Monday, October 31, 2016
Recreational, commuter biking linked to lower cardiovascular disease risk
People who bike regularly, either for pleasure or as a way to commute, appear to have a lower risk of cardiovascular disease, according to two separate studies published simultaneously in the American Heart Association's journal Circulation and Journal of the American Heart Association, the AHA/ASA's Open Access Journal.
While structured cycling as part of a formal workout routine is already known to guard against cardiovascular illness, little is known about the effects of habitual biking done for leisure or as a way to commute. Together, the findings from the newly published studies suggest that leisure and commuter biking may be an important public health strategy in large-scale efforts to reduce cardiovascular risk.
In the Circulation study, 45,000 Danish adults (aged 50 to 65) who regularly biked for recreation or to commute had between 11 percent and 18 percent fewer heart attacks during a 20-year follow-up (1993-2013).
The analysis showed that as little as half an hour of biking per week provided some protection against coronary artery disease. Additionally, people who took up biking during the first five years the authors followed them had about a 25 percent lower risk of developing heart disease, compared with those who remained non-bikers in the subsequent 15-year period.
Researchers caution that their findings do not prove definitively that riding a bike for leisure or to and from work can prevent heart attacks. However, they say, the lower number of cardiovascular events observed among those who biked on a regular basis is a strong indicator that such activity can boost cardiovascular health.
"Finding time for exercise can be challenging for many people, so clinicians working in the field of cardiovascular risk prevention should consider promoting cycling as a mode of transportation," said Anders Grøntved, M.Sc., M.P.H., Ph.D., senior study author and associate professor of physical activity epidemiology at the University of Southern Denmark.
Researchers also tracked participants' overall exercise habits, activity levels and frequency of bicycle riding, along with heart disease risk factors, such as blood pressure, weight, cholesterol, smoking, diet and alcohol consumption. Participants were asked to provide information about cycling habits at the onset of the study and once more in five years.
In all, there were 2,892 heart attacks during the 20-year follow-up. Researchers estimate that more than 7 percent of all heart attacks could have been averted by taking up cycling and keeping it up on a regular basis.
"Because recreational and commuter biking is an easy way to make physical activity part of one's routine in a non-structured and informal fashion, based on the results, public health authorities, governments and employers ought to consider initiatives that promote bicycle riding as a way to support large-scale cardiovascular disease prevention efforts," said Kim Blond, M.Sc, lead author and research assistant at the University of Southern Denmark.
The Journal of the American Heart Association study revealed that middle-aged and older Swedish adults who biked to work were less likely than non-bikers to be obese, have high cholesterol, high blood pressure or pre-diabetes -- all critical drivers of cardiovascular risk.
Researchers followed more than 20,000 people in their 40s, 50s and 60s over 10 years and monitored their commuting habits, weight, cholesterol levels, blood glucose and blood pressure.
At the beginning of the study, active commuters (biked to work) were 15 percent less likely to be obese, 13 percent less likely have high blood pressure, 15 percent less likely to have high cholesterol and 12 percent less likely to have pre-diabetes or diabetes, compared with passive commuters (used public transportation or drove to work).
During a follow-up exam 10 years later, the portion of study participants who switched from passive commuting to active commuting also had an improved risk profile. They were less likely to be obese, have diabetes, hypertension or elevated cholesterol, compared with non-bikers.
Collectively, at the 10-year follow-up, those who maintained biking or took up biking at some point had a 39-percent lower risk of obesity, 11 percent lower risk of high blood pressure, 20 percent lower risk of high cholesterol and 18 percent lower diabetes risk.
"We found active commuting, which has the additional advantages of being time-efficient, cheaper and environmentally friendly is also great for your health," said Paul Franks, Ph.D., senior study author, professor in the Department of Clinical Sciences at Lund University in Sweden and guest professor at Umeå University in Sweden. "The multiple advantages of active commuting over structured exercise may help clinicians convey a message that many patients will embrace more readily than being told to join a gym, go for a jog or join a sports team."
Researchers noted that there was no minimum amount of time or distance required to reduce one's risk, even though people who biked longer or more often experienced small additional gains in risk reduction.
Because the study was observational, it is difficult to establish a cause-and-effect relationship between improved cardiovascular health and commuter biking, but the findings do indicate a strong cardio-protective effect from cycling.
Based on their findings, researchers also estimated that maintaining biking habits or switching from passive commuting to biking may have prevented 24 percent of obesity cases, 6 percent of hypertension diagnoses, 13 percent of high cholesterol diagnoses, and 11 percent of the cases of diabetes.
"The really good news here is that it's never too late to benefit from an active lifestyle," Franks said. "People who switched from passive to active commuting saw considerable gains in their cardiovascular health."
Blood pressure that spikes only in the doctor's office is no concern for most, but it is for some
White coat hypertension, where patients have high blood pressure readings in a medical setting but normal blood pressure outside the doctor's office, is most likely an innocuous condition that is not a predictor of heart disease or stroke -- except in a small group of older patients, according to a study published online today in the Journal of the American College of Cardiology.
White coat hypertension, identified more than 30 years ago, is a common condition that is thought to be the result of patients feeling stressed in a medical setting or in the presence of clinicians in "white coats," though some research has suggested it is associated with health risks. Recent studies have shown white coat hypertension occurs more frequently in older patients and the difference between the blood pressure readings in the two settings becomes larger with age.
To find out if white coat hypertension is an indicator of increased risk for heart disease, a researcher from the University of California, Irvine, in collaboration with the International Database on Ambulatory blood pressure in relation to Cardiovascular Outcomes, looked at 653 patients identified with white coat hypertension from the international hypertension database and compared them to 653 patients of similar age and similar risk for developing heart disease.
The researchers, led by Stanley S. Franklin, M.D., found that during a follow up period of about 10.6 years there was no difference in the number of new heart-related health events between younger subjects, below age 60, with normal blood pressure and those of a similar age and risk profile with white coat hypertension.
A difference was seen in older patients. Out of 92 high-risk subjects age 60 and older, there were 18 more new cardiovascular events in the follow up period for those diagnosed with white coat hypertension than the same number of subjects of similar age and otherwise similar risk profile with normal blood pressure.
Researchers said the results support the hypothesis that a small number of patients considered to have white coat hypertension actually have isolated systolic hypertension, a common condition where the top number in the blood pressure reading (systolic blood pressure) is too high, but the bottom number (the diastolic blood pressure) is normal. Isolated systolic hypertension can be an indicator of risk for future heart disease or stroke.
The authors conclude multiple blood pressure readings, including readings outside a clinical setting, are necessary to accurately identify cardiovascular risk, especially in older high-risk patients.
In an accompanying editorial, Giuseppe Mancia, M.D., and Guido Grassi, M.D., of the University of Milano Bicocca, Milan, Italy, said that the study group may not have been large enough or studied over a long enough time period to identify risk in the younger patients, so conclusions about younger patients may not be accurate, and more research is needed to fully understand the complexities of white coat hypertension.
Raising HDL does not likely reduce a person's risk of heart disease
Low and very high levels of HDL, or "good cholesterol" are associated with a higher risk of dying from heart disease, cancer and other causes, according to a study today in the Journal of the American College of Cardiology. The findings from the first of its kind study suggest that a low level of good cholesterol may not be a heart disease risk factor on its own and that raising HDL does not likely reduce a person's risk of heart disease.
To reduce risk of suffering a cardiac episode, many patients are treated to lower their LDL, or "bad cholesterol," with statins--a medication used to block the enzyme needed in the body to produce cholesterol. However, some people don't respond to this treatment, so researchers have been studying HDL and whether raising levels of "good cholesterol" could have the same benefits as lowering "bad cholesterol."
Researchers studied over 631,000 individuals without prior cardiovascular conditions through the CANHEART cohort, a research database that links together multiple individual-level population-based datasets on sociodemographics, cardiac risk factors and comorbidities, medications, etc., in Ontario, Canada. Patients were between 40 and 105 years old, with an average age of 57.2, and lived in Ontario for at least two years as of January 1, 2008. This was the first study to evaluate the association between HDL and death in individuals living in the same environment and exposed to the same health care system.
The study cohort was divided into groups based on their HDL to allow researchers to examine the relationship between HDL levels and mortality. Researchers compared the HDL levels of people with healthier lifestyles to those with less healthy habits. The lowest levels of HDL were seen in people who were socioeconomically disadvantaged and who had less healthy lifestyle behaviors, more cardiac risk factors and more medical comorbidities.
However, even when adjusting for lifestyle factors, lower HDL levels were still associated with increased risk of both cardiovascular death and non-cardiovascular related death, such as death from cancer. Individuals with very high HDL levels had an increased risk of non-cardiovascular related death.
Researchers said their findings are similar to other studies showing low HDL levels are associated with a higher risk of cardiovascular disease death, but this study is among the first to show a similar relationship between HDL and cancer death and other causes of death.
Researchers said they are unsure why very high levels of HDL increased levels of non-cardiovascular related death, but other studies have suggested this could be related to increased alcohol intake.
In conclusion, researchers said this study casts doubt on HDL being used as an independent risk factor for cardiovascular disease or for raising HDL levels to be used by itself as an intervention to reduce the risk of dying from heart disease.
"The link between good cholesterol and heart disease is complex, but it seems certain that there is a connection between people with low good cholesterol levels and other well-known risk factors for heart disease such as poor diet and exercise habits and other medical conditions," said Dennis T. Ko, M.D., M.Sc., lead author of the study and an associate professor at the Institute for Clinical Evaluative Sciences in Toronto. "Focusing on raising HDL is likely not going to help these patients, but these findings show that one of the best interventions in treating and preventing heart disease continues to be lifestyle changes."
Limitations of the study include that researchers were unable to examine some potentially important aspects of HDL such as the relationship of particle sizes, subclasses or function with cardiovascular or non-cardiovascular mortality because these data are not available at the population level. Also, they did not have smoking status or alcohol use data for the entire population studied, but were able to supplement that data from an additional survey.
Diet can impact migraines
Eliminating that morning 'Cup of Joe,' consuming processed foods high in nitrites or monosodium glutamate (MSG) and enjoying too much alcohol are potential headache triggers for individuals battling migraines, says Vincent Martin, MD, professor in the Department of Internal Medicine at the University of Cincinnati (UC) College of Medicine.
There are two different approaches to preventing headaches with diet. The first approach would be an elimination diet that avoids foods and beverages known to trigger headaches. The second approach would be follow a comprehensive diet whose very composition may prevent headaches, explains Martin, co-director of the Headache and Facial Pain Center at UC Gardner Neuroscience Institute and an expert in the area of migraine. His conclusions and others for migraineurs come after performing an exhaustive literature review of more than 180 research studies on the subject of migraine and diet.
Martin's two-part review, "Diet and Headache" is available online in the scholarly publication Headache: The Journal of Head and Face Pain. It is co-authored by Dr. Brinder Vij, associate professor in the UC Department of Neurology and Rehabilitation Medicine.
"One of the most important triggers for headache is the withdrawal of caffeine," says Martin, who also sees patients at UC Health. "Let's say you regularly pound down three or four cups of coffee every morning and you decide to skip your morning routine one day, you will likely have full-fledged caffeine withdrawal headache that day."
That said, too much coffee may also present a risk, no more than 400 milligrams daily--one cup is 125 milligrams--is probably the maximum for migraine patients, says Martin. "Large amounts of caffeine can bring on anxiety and depressive symptoms as well as headaches," he explains.
Another trigger for migraine is MSG, which is a flavor enhancer used in a variety of processed foods, including frozen or canned foods, soups, international foods, snack foods, salad dressing, seasoning salts, ketchup, barbecue sauce, and heavily in Chinese cooking, says Martin.
"You eliminate it by eating fewer processed foods," explains Martin. "You eat more natural things such as fresh vegetables, fresh fruits and fresh meats. MSG is most provocative when consumed in liquids such as soups."
Nitrites are preservatives food in processed meats such as bacon, sausage, ham and lunch meat to preserve color and flavor. Martin says a diary study found that five percent of individuals with migraine were statistically more likely to have an attack on days when they consume nitrites. Use of nitrites in foods has declined with stronger government regulation though checking labels remains a good idea, he explains.
Alcohol is one of the most commonly reported dietary trigger factors for migraine and studies suggest vodka and red wines, especially those with highest histamine content are problematic, says Martin. There is a lot of interest in gluten-free diets, but they are only helpful in lessening headaches if the individuals suffer from celiac disease, which can be established by a positive blood test or intestinal biopsy, he adds.
There have been three comprehensive diets whose very composition may prevent headaches such as low fat and low carbohydrate diets as well as those that increase the amount of omega-3 fatty acids and decrease the amount of omega-6 fatty acids, according to Martin.
Vij says low fat diets restrict the amount of fat in the diet to less than 20 percent of your daily energy requirements. "The beauty of these diets is that they not only reduce headaches, but may produce weight loss and prevent heart disease", says Vij.
Low carbohydrate diets such as ketogenic diets can reduce headache frequency, but it's not something to consider without strict physician supervision. The diet limits carbohydrates more than the well-known Atkins diet, Vij explains.
One of the most promising diets for those with more frequent attacks of migraine is one that boosts your omega-3 fats while lessoning your omega-6 levels and that means tossing out polyunsaturated vegetable oils (corn, sunflower, safflower, canola and soy) in favor of flaxseed oil, says Martin. Foods to consume would include flaxseed, salmon, halibut, cod and scallops while those to avoid would be peanuts and cashews.
"Persons with headache and migraine have more dietary options than ever. Ultimately a healthy headache diet excludes processed foods, minimizes caffeine and includes a lot of fruits, vegetables, fish and lean meats", Martin says. He adds, "After all, you are what you eat."
Friday, October 28, 2016
Vitamin E can modify the risk of pneumonia in some older men depending on their lifestyle
Many people have been advised to take vitamin supplements to
boost their immune systems. However, a recent study published in the British
Journal of Nutrition found that taking vitamin E supplements led to an
increased risk of pneumonia for more than one in four older men (28%) who
smoked and did not exercise. However, the opposite effect was true for older
men who exercised and did not smoke - in that vitamin E actually decreased
their risk of contracting pneumonia.
The findings of this study - which
focused on men aged 50 to 69 years old at the baseline of the trial- are
particularly striking because analyses in nutritional epidemiology usually
assume a uniform effect of a nutrient. However, the author of the study - Dr.
Harri Hemilä of the University of Helsinki, Finland - found that the effect of
vitamin E on health outcomes may depend on various characteristics of people
and their lifestyles. Therefore, a single universal estimate of the vitamin E
effect might be substantially misleading for some population groups.
The author studied the effect of
vitamin E on the risk of pneumonia in a large randomised trial
(Alpha-Tocopherol Beta-Carotene Cancer Prevention Study - ATBC) conducted in
Finland between 1985 and 1993. There were 898 cases of pneumonia among 29,133
participants of the study.
Drawing on the I2 statistic for the
first time for this type of analysis, Dr. Hemilä concluded that nearly all
variation in the vitamin E effect on pneumonia risk over five subgroups was
explained by true differences in the vitamin E effect rather than by chance
variation.
Vitamin E increased pneumonia risk by
68% among men who had the highest exposure to smoking and who did not exercise
(22% of the ATBC participants), while vitamin E actually decreased pneumonia
risk by 69% among participants who had the least exposure to smoking and who
exercised during their leisure time (7·6% of the ATBC participants). The author
claims that these findings refute there being a uniform effect of vitamin E
supplementation on the risk of pneumonia.
The high level of true heterogeneity
in the effect of vitamin E on pneumonia has important implications. First, it
provides a strong argument against the opinion that subgroup analyses of
randomised trials should be strongly discouraged because they can lead to false
positive findings due to the multiple comparison problem. Second, the average
effects of vitamin E that are calculated in meta-analyses may not be valid for
many population groups. Third, in cohort studies, confounders are adjusted to
allow the calculation of a single estimate of effect over the study population.
However, when several variables modify the effect of vitamin E, it is evident
that the effects of vitamin E should be investigated separately in
subpopulations with those characteristics.
Given the current limited
understanding about who might benefit, Dr. Hemilä recommends that vitamin E
should not be suggested for the general population for improving the immune
system. The author concludes that there is a need for further research on
vitamin E for non-smoking elderly men who exercise in their leisure time.
High blood pressure can impair cognitive function, pose risk for Alzheimer's
High blood pressure in middle age can lead to impaired cognition and is a potential risk factor for Alzheimer's disease, according to a statement from the American Heart Association co-authored by Loyola Medicine neurologist José Biller, MD.
Dr. Biller is a member of the multidisciplinary panel of experts that wrote the statement, published in the heart association journal Hypertension. Dr. Biller is chair of the department of neurology of Loyola University Chicago Stritch School of Medicine. The panel is chaired by Constantino Iadecola, MD, of Weill Cornell Medicine and co-chaired by Kristine Yaffe, MD, of the University of California San Francisco.
Dementia affects an estimated 30 to 40 million people worldwide, and the number is expected to triple by 2050 due to an aging population and other factors.
An estimated 80 million people in the United States have hypertension, and the brain is among the organs most affected. Except for age, hypertension is the most important risk factor for vascular problems in the brain that lead to stroke and dementia.
There is consistent evidence that chronic high blood pressure during middle age (40 to 64) is associated with altered cognitive function in both middle age and late life (65 to 84). Cognitive abilities that are affected include memory, speed of processing and executive function (ability to organize thoughts, manage time, make decisions, etc.)
The effect of high blood pressure in late life is less clear. Some studies suggest it's harmful, while other research suggests it may improve cognition. This highlights "the complexities of recommending uniform levels of blood pressure across the life course," the expert panel wrote.
Observational studies have demonstrated that high blood pressure causes atherosclerosis (hardening of the arteries) and other damage to the brain's blood vessels, leading to reduced blood flow to brain cells. But evidence from clinical trials that treating blood pressure improves cognition is not conclusive.
After carefully reviewing available studies, the panel concluded there are not enough data to make evidence-based recommendations. However, judicious treatment of high blood pressure, taking into account goals of care and the patient's individual characteristics, "seems justified to safeguard vascular health and, as a consequence, brain health," the panel concluded.
The paper is titled, "Impact of hypertension on cognitive function: a scientific statement from the American Heart Association."
Excess lutein supplements linked to formation of crystal deposits in the eyes
In the past decade, ophthalmologists have been prescribing nutritional supplements to be taken daily to prevent or slow vision loss from age-related macular degeneration (AMD). Now, using nutritional supplements for eye health has become more common. But does increasing the recommended dose increase your protection?
A case report appearing online in JAMA Ophthalmology from the Moran Eye Center at the University of Utah reveals what can happen when a patient takes more of a supplement than their body needs.
In the article, Crystalline Maculopathy Associated with High-Dose Lutein Supplementation, principal investigator Paul Bernstein, M.D., Ph.D., describes a patient with no AMD or vision problems who was referred to the retinal clinic for crystal deposits in the macular region of the retina in both eyes. With physician follow-up, it was learned that for the past eight years, the patient took a daily lutein supplement (20 mg) in addition to a diet rich in lutein, which included a broccoli, kale, spinach, and avocado smoothie every morning; she was therefore consuming much more than twice the recommended dose of lutein for an AMD patient (10 mg per day).
Lutein is part of the AMD prevention supplement regimen that was created based on results from the AREDS2 (Age-Related Eye Disease Study 2) clinical trial. In that trial, researchers found that patients at high risk for visual loss from AMD who took lutein (10 mg) and zeaxanthin (2 mg) supplements reduced their risk of progressing to late stage AMD. Lutein and zeaxanthin are carotenoids--antioxidants made by plants--that are believed to neutralize light-induced damage in the eye. Humans don't make carotenoids, so they can only be added to the body by eating plants or taking supplements.
"When we looked at the patient's carotenoid levels in serum, skin, and the retina, all measurements were at least two times greater than carotenoid levels in patients not taking nutritional supplements," said Bernstein. "The patient quit taking the lutein supplement, but maintained her diet rich in lutein, and, after seven months, the crystals in the right eye disappeared."
While AREDS2 supplements are recommended to patients at higher risk for AMD, there has also been increased use in the general population. Bernstein's advice for his patients is that "everyone should eat an 'eye-healthy' diet rich in colorful fruits and vegetables, and individuals should take an AREDS2 supplement if their ophthalmologist detects signs of AMD." This case report must followed up by a larger clinical trial before the results can be considered conclusive but it serves as an indicator that there may be negative effects from consuming lutein considerably higher than the recommended AREDS2 dose.
Thursday, October 27, 2016
Optimal walking and cycling speeds to reduce air pollution inhalation
Cyclists should be riding at speeds between 12 and 20 kilometres per hour (7-12 mph) on city roads, while pedestrians should be moving at two to six kilometres per hour (1.2-3.6 mph) to minimize their inhalation of air pollution while still getting the health benefits of exercise, according to new UBC research.
"The faster you move, the harder you breathe and the more pollution you could potentially inhale, but you also are exposed to traffic for a shorter period of time. This analysis shows where the sweet spot is," said Alex Bigazzi, a UBC transportation expert in the department of civil engineering and school of community and regional planning who conducted this analysis.
Using a U.S. Census-based computer model of 10,000 people, Bigazzi calculated ideal travel speeds that he calls the minimum-dose speeds (MDS) for different age and sex groups. For female cyclists under 20, the ideal speed linked to the least pollution risk is 12.5 kilometres per hour on average on a flat road. For male cyclists in the same age group, it's 13.3 kilometres per hour. Ideal travel speeds were at 13 and 15 kilometres per hour for female and male cyclists in the 20-60 age group.
Female and male pedestrians under 20 years old should be walking at speeds around three kilometres per hour, while their older counterparts should look at reaching at least four kilometres per hour, to breathe in the least amount of pollution over a trip. Bigazzi also computed these ideal travel speeds for other road grades.
"If you move at much faster speeds than the MDS--say, cycling around 10 kilometres faster than the optimal range--your inhalation of air pollution is significantly higher," said Bigazzi. "The good news is, the MDS numbers align pretty closely with how fast most people actually travel."
The findings, which build on Bigazzi's recent research on the high amounts of toxic chemicals absorbed by cyclists on busy city streets, are described in a paper published recently in the International Journal of Sustainable Transportation.
Vitamin D can reduce asthma attacks
A recent Cochrane Review has found evidence from randomised trials, that taking an oral vitamin D supplement in addition to standard asthma medication is likely to reduce severe asthma attacks.
Asthma is a common chronic disease affecting about 300 million people worldwide. The symptoms of asthma include wheezing, coughing, chest tightness and shortness of breath.
Low blood levels of vitamin D have been linked to increased risk of asthma attacks in children and adults with asthma. There has been a growing interest in the potential role of vitamin D in asthma management because it might help to reduce upper respiratory infections, (such as the common cold) that can lead to exacerbations of asthma. Several clinical trials have tested whether taking vitamin D as a supplement has an effect on asthma attacks, symptoms and lung function in children and adults with asthma.
The team of Cochrane researchers found seven trials involving 435 children and two studies, involving 658 adults. The study participants were ethnically diverse, reflecting the broad range of global geographic settings, involving Canada, India, Japan, Poland, the UK, and the U.S. The majority of people recruited to the studies had mild to moderate asthma, and a minority had severe asthma. Most people continued to take their usual asthma medication while participating in the studies. The studies lasted for between six and 12 months
The researchers found that giving an oral vitamin D supplement reduced the risk of severe asthma attacks requiring hospital admission or emergency department attendance from 6% to around 3%.They also found that vitamin D supplementation reduced the rate of asthma attacks needing treatment with steroid tablets. These results are based largely on trials in adults. They also found that vitamin D did not improve lung function or day-to-day asthma symptoms, and that it did not increase the risk of side effects at the doses that were tested.
The Cochrane Review's lead author, Professor Adrian Martineau from the Asthma UK Centre for Applied Research, Queen Mary University of London, said, "We found that taking a vitamin D supplement in addition to standard asthma treatment significantly reduced the risk of severe asthma attached, without causing side effects."
He added, "This is an exciting result, but some caution is warranted. First, the findings relating to severe asthma attacks come from just three trials: most of the patients enrolled in these studies were adults with mild or moderate asthma. Further vitamin D trials in children and in adults with severe asthma are needed to find out whether these patient groups will also benefit. Second, it is not yet clear whether vitamin D supplements can reduce risk of severe asthma attacks in all patients, or whether this effect is just seen in those who have low vitamin D levels to start with. Further analyses to investigate this questions are on-going, and results should be available in the next few months."
Exercise is an excellent preventive and curative treatment for many diseases
Researchers, it is hoped, will one day find a miracle cure for all kinds of diseases. Yet over and over again it has been shown that even if it takes a little more effort than swallowing a little pill, exercise is an excellent preventive and curative treatment for many diseases. A new study, whose preliminary results will be presented today at the Canadian Cardiovascular Congress and soon be published in the Journal of Cardiopulmonary Rehabilitation and Prevention, also supports this finding. The study shows that even low physical fitness, up to 20% below the average for healthy people, is sufficient to produce a preventive effect on most of the risk factors that affect people with cardiovascular disease.
"This is great news for people with heart disease who have difficulty adhering to a regular -- mainly aerobic -- exercise program," said Daniel Curnier, a professor at the University of Montreal's Department of Kinesiology, who led the study. "Small improvements in their fitness level are enough. You don't have to be an great athlete to benefit from these effects."
"We know from many studies that good physical fitness reduces cardiovascular mortality, and that physical activity has a positive impact on cardiovascular risk factors following a rehab program," said Maxime Caru, a doctoral student in human kinetics at UdeM and lead author of the study. "However, the impact of physical fitness level on risk factors has remained an open question. That is why our research team asked the following question: "Is good physical condition required to produce a preventive effect on these cardiovascular risk factors?"
Pedalling with heart
Changes in society, marked by industrialization, have had a significant impact on the physical activity of humans, who have become increasingly sedentary over the years. The increase in risk factors, including abdominal circumference, depression, diabetes, dyslipidemia, hypertension, obesity, excess weight, and smoking -- along with physical inactivity -- provides the perfect storm for developing heart disease, which is one of the leading causes of death in the world, representing 31% of global mortality. And it has continued to grow in recent years.
"It is common to meet people entering a cardiac rehab centre who are totally out of shape and whose exercise is irregular or non-existent, which has a harmful effect on general and cardiovascular health," said Caru, who is also a doctoral student in psychology at the University of Paris-Nanterre.
To measure the impact of physical fitness on heart disease risk factors, the researchers selected 205 men and 44 women with heart disease, including coronary artery disease, stroke, congestive heart failure, and heart valve disease, and had them undergo a cycle ergometer (stationary bike) stress test to determine their fitness level.
The results showed that normal physical fitness, even up to 20% below the population average, is sufficient to have a preventive effect on five of the eight risk factors affecting people with cardiovascular disease -- abdominal circumference, diabetes, hypertension, obesity, and excess weight. Normal physical fitness means having the physical fitness of a person of the same weight, height, sex, and age, and who is disease-free. The easiest way to achieve this is to follow the recommendations of the World Health Organization -- 150 minutes per week of moderate exercise or 75 minutes of vigorous exercise.
Depression: higher standards
Depression is a significant risk factor for cardiovascular disease because cardiac patients who have experienced a depressive episode have recurring heart problems. The results of the study have demonstrated the importance of a good fitness level, before and after a heart attack, to produce the preventive effect on depression.
The study sheds new light on the overall role of physical fitness in the development of cardiovascular risk factors in patients with cardiovascular disease. However, the researchers stress the importance for cardiac patients to consult their doctor before embarking on an exercise program and to consult a kinesiologist: "Only these professionals are able to know which type of exercise is safe for your condition and how to implement an exercise program," warn the authors.
About the study
Maxime Caru and Daniel Curnier presented "Preventive fraction of physical fitness on risk factors in cardiac patients" at the Canadian Cardiovascular Congress on October 21, 2016. The scientific article, signed by Maxime Caru, Laurence Kern, Marc Bousquet, and Daniel Curnier will soon be published in the Journal of Cardiopulmonary Rehabilitation and Prevention.
Tuesday, October 25, 2016
New guideline on calcium and vitamin D supplementation
A new evidence-based clinical guideline from the National Osteoporosis Foundation (NOF) and the American Society for Preventive Cardiology (ASPC) says that calcium with or without vitamin D intake from food or supplements that does not exceed the tolerable upper level of intake (2,000 to 2,500 mg/d) should be considered safe from a cardiovascular standpoint. Obtaining calcium from food sources is preferred, but supplements can be used to address dietary shortfalls. The guideline is published in Annals of Internal Medicine.
Calcium supplements have been recommended for persons who do not consume adequate calcium from their diet as a standard strategy for preventing osteoporosis-related fractures. Conflicting reports have suggested that calcium intake, particularly from supplements, may have either beneficial or harmful effects on cardiovascular outcomes. To update the evidence on calcium and vitamin D, investigators from the Tufts University School of Medicine reviewed randomized trials and prospective cohort studies published since their last evidence report in 2009. Their findings were used to inform the joint clinical guideline from NOF and ASPC.
A total of 31 studies were included in the review. Of the four randomized trials reviewed, none found a statistically significant difference in risk for cardiovascular events or mortality between groups receiving supplements of calcium alone or calcium plus vitamin D compared to those receiving placebo. None of the 27 cohort studies included in the review conclusively linked total, dietary, or supplemental calcium intake levels to cardiovascular disease and cerebrovascular disease, mortality, or all-cause mortality. Because excessive calcium intake is nearly impossible to achieve via diet, safety of supplementation had been an area of concern. Of the three supplementation-specific trials included in the review, none found a statistically significant effect of calcium supplementation on cardiovascular disease outcomes. Based on this moderate-quality evidence, the review team concluded that calcium intake from food or supplement sources at levels within the recommended tolerable range should be considered safe for generally healthy adults.
Increasing muscle strength can improve brain function
Increased muscle strength leads to improved brain function in adults with Mild Cognitive Impairment (MCI), new results from a recent trial led by the University of Sydney has revealed.
With 135 million people forecast to suffer from dementia in 2050, the study's findings--published in the Journal of American Geriatrics today--have implications for the type and intensity of exercise that is recommended for our growing ageing population.
Mild Cognitive Impairment defines people who have noticeably reduced cognitive abilities such as reduced memory but are still able to live independently, and is a precursor to Alzheimer's disease.
Findings from the Study of Mental and Resistance Training (SMART) trial show, for the first time, a positive causal link between muscle adaptations to progressive resistance training and the functioning of the brain among those over 55 with MCI.
The trial was conducted in collaboration with the Centre for Healthy Brain Ageing (CHeBA) at University of New South Wales and the University of Adelaide.
"What we found in this follow up study is that the improvement in cognition function was related to their muscle strength gains" said lead author Dr Yorgi Mavros, from the Faculty of Health Sciences, at University of Sydney.
"The stronger people became, the greater the benefit for their brain."
SMART was a randomised, double-blind trial involving 100 community-dwelling adults with MCI, aged between 55 and 86. They were divided into four groups doing either:Resistance exercise and computerised cognitive training;
- Resistance exercise and a placebo computerised training (watching nature videos);
- Brain training and a placebo exercise program (seated stretching/calisthenics); or
- Placebo physical exercise and placebo cognitive training.
The primary outcomes of a paper published in 2014 found these participants' global cognition improved significantly after the resistance training, as measured by tests including the Alzheimer's disease Assessment Scale-Cognitive scale. The cognitive training and placebo activities did not have this benefit. The benefits persisted even 12 months after the supervised exercise sessions ended.
"The more we can get people doing resistance training like weight lifting, the more likely we are to have a healthier ageing population," said Dr Mavros.
"The key however is to make sure you are doing it frequently, at least twice a week, and at a high intensity so that you are maximising your strength gains. This will give you the maximum benefit for your brain."
These new findings reinforce research from the SMART trial published earlier this year, whereby MRI scans showed an increase in the size of specific areas of the brain among those who took part in the weight training program. These brain changes were linked to the cognitive improvements after weight lifting.
"The next step now is to determine if the increases in muscle strength are also related to increases in brain size that we saw," said senior author Professor Maria Fiatarone Singh, geriatrician at University of Sydney.
"In addition, we want to find the underlying messenger that links muscle strength, brain growth, and cognitive performance, and determine the optimal way to prescribe exercise to maximise these effects."
Long-term exposure to air pollution linked to high blood pressure
Long-term exposure to air pollution is linked to a greater incidence of high blood pressure, according to the largest study to investigate the effects of both air pollution and traffic noise by following over 41,000 people in five different countries for five to nine years.
The study, which is published today (Tuesday) in the European Heart Journal [1], found that among adults, up to one extra person per 100 people of the same age group living in the most polluted areas of cities would develop high blood pressure (hypertension) compared to those living in the less polluted areas. This risk is similar to the effect of being overweight with a body mass index (BMI) between 25-30 compared to people with normal weight (BMI 18.5-25). High blood pressure is the most important risk factor for premature illness and death.
This study is one of the first to investigate both air pollution and traffic noise simultaneously and it found that traffic noise is associated with an increase in cases of hypertension as well. The way the study was conducted enabled the researchers to estimate the risk that was linked to air pollution and the risk linked to noise separately. The association of air pollution with hypertension remained even when exposure to traffic noise was considered in the analysis. The researchers say this is an important finding because there are differing ways of reducing air pollution and noise.
A total of 41,072 people living in Norway, Sweden, Denmark, Germany and Spain participated in the study, which was part of the "European Study of Cohorts for Air Pollution Effects" (ESCAPE) project that is investigating long-term effects of exposure to air pollution on human health in Europe. Information on blood pressure was gathered when the participants joined the study and during a follow-up examination in later years. None had hypertension when they joined the study, but during the follow-up period 6,207 people (15%) reported that they developed hypertension or started to take blood pressure-lowering medications.
Between 2008 and 2011, the researchers measured air pollution during three separate two-week periods (to allow for seasonal effects). They used filters to capture information on concentrations of polluting particles known as "particulate matter" (PM) of different sizes: PM10 (particles less than or equal to 10 microns [2] in diameter), PM2.5 (less than or equal to 2.5 microns), PMcoarse (PM10 minus PM2.5) and PM2.5 absorbance (a measurement of soot particles). These measurements were taken at 20 sites in each of the areas being studied, and measurements of nitrogen oxides were measured at 40 different sites in each area. Traffic density was assessed outside the homes of the participants and traffic noise was modelled according to the EU Directive on environmental noise.
The researchers found that for every five micrograms [3] per cubic metre (5 μg/m3) of PM2.5, the risk of hypertension increased by a fifth (22%) in people living in the most polluted areas compared to those in the least polluted areas. Higher soot concentrations also increased the risk.
For exposure to chronic traffic noise, the researchers found that people living in noisy streets, where there were average night time noise levels of 50 decibels, had a six percent increased risk of developing hypertension compared to those living on quieter streets where average noise levels were 40 decibels during the night.
Professor Barbara Hoffmann, Professor of Environmental Epidemiology at the Centre for Health and Society at Heinrich-Heine-University of Düsseldorf, Germany, who led the analysis, said: "Our findings show that long-term exposure to particulate air pollution is associated with a higher incidence of self-reported hypertension and with intake of anti-hypertensive medication. As virtually everybody is exposed to air pollution for all of their lives, this leads to a high number of hypertension cases, posing a great burden on the individual and on society.
"Exposure to traffic noise shares many of the same sources with air pollution and so has the potential to confound the estimates of the adverse effects of pollution on human health. However, this study controlled for traffic noise exposure and found that the associations of air pollution with hypertension did not vanish. This is important because preventive measures for air pollution and noise differ.
"One very important aspect is that these associations can be seen in people living well below current European air pollution standards. This means, the current legislation does not protect the European population adequately from adverse effects of air pollution. Given the ubiquitous presence of air pollution and the importance of hypertension as the most important risk factor for cardiovascular disease, these results have important public health consequences and call for more stringent air quality regulations."
The study found there were higher average levels of pollution in the central and southern European study areas - Germany and Spain - than in the Scandinavian areas - Norway, Sweden and Denmark. Exposure to traffic noise and traffic load was highest in the study areas of Sweden and Spain.
The researchers say that it is possible that air pollution and noise affect different, or not completely overlapping, pathways involved in disturbances in the way the body normally functions. Possible biological mechanisms for the adverse effect of air pollution on the functioning of the heart and blood vessels include local and systemic inflammation, oxidative stress (a build-up of damaging molecules in the body), and an imbalance in correct functioning of the nervous system. Noise is thought to affect the functioning of both the nervous and hormonal systems.
Cut dietary omega 6 and boost omega 3 to curb soaring obesity rates
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Governments and international bodies should ditch their obsession with calories and energy expenditure to curb soaring obesity rates, and instead focus on restoring the correct balance of omega 6 and omega 3 fatty acids in the food supply chain and diet, urge experts in an editorial in the online journal Open Heart.
Nutrition policies based purely on the mismatch between 'calories in and energy out' in the belief that all calories are equal, have "failed miserably over the past 30 years," argue Drs Artemis Simopoulos of the Center for Genetics, Nutrition, and Health, Washington DC, and James DiNicolantonio of Saint Luke's Mid America Heart Institute, Kansas.
So much so, that 1.5 billion people around the globe are now overweight while 500 million are obese.
Major changes in food supply over the past century, as a result of technological advances and modern farming methods, have distorted the omega 6 to omega 3 fatty acid ratio in the typical Western diet, which developing countries are now also increasingly adopting, say the authors.
The production of vegetable oils high in omega 6, such as sunflower, safflower, and corn oils, has soared, while animal feeds have switched from grass, which contains omega 3, to grain, resulting in higher levels of omega 6 in meat, eggs, and dairy products.
This matters because while the body needs both types of fatty acid, human beings evolved to eat a diet containing equal amounts of omega 6 and omega 3 in it. But that dietary ratio is now a belt-busting 16:1 rather than the healthy 1: 2/1, the authors contend.
Fatty acids act directly on the central nervous system, influencing food intake and the sensitivity of the hormones involved in blood sugar control (insulin) and appetite suppression (leptin).
But too much omega 6 promotes inflammation and is prothrombotic (increasing the risk of blood clotting) as well as boosting production of white fat tissue that is stored rather than 'good' energy-burning brown fat tissue.
And copious amounts of white fat and chronic inflammation are the hallmarks of obesity, the authors point out, as well as being linked to type 2 diabetes, cardiovascular disease, metabolic syndrome, and cancer.
Furthermore, different populations metabolise fatty acids differently, making them more or less vulnerable to the consequences of an imbalance, they add.
They point to several key studies that have shown a strong link between the dietary omega 6 to omega 3 ratio and long term weight gain.
"The time has come to return the omega 3 fatty acids in the food supply and decrease the omega 6 fatty acids by changing the cooking oils and eating less meat and more fish," they write. "The composition of the food supply must also change to be consistent with the evolutionary aspects of diet and the genetics of the population," they add.
"The scientific evidence to balance the omega 6 to omega 3 ratio is robust and necessary for normal growth and development, prevention and treatment of obesity and its comorbidities, including diabetes, cardiovascular disease and cancer," they continue.
And they conclude: "It is the responsibility of governments and international organisations to establish nutrition policies based on science and not continue along the same path of focusing exclusively on calories and energy expenditure, which have failed miserably over the past 30 years."
Governments and international bodies should ditch their obsession with calories and energy expenditure to curb soaring obesity rates, and instead focus on restoring the correct balance of omega 6 and omega 3 fatty acids in the food supply chain and diet, urge experts in an editorial in the online journal Open Heart.
Nutrition policies based purely on the mismatch between 'calories in and energy out' in the belief that all calories are equal, have "failed miserably over the past 30 years," argue Drs Artemis Simopoulos of the Center for Genetics, Nutrition, and Health, Washington DC, and James DiNicolantonio of Saint Luke's Mid America Heart Institute, Kansas.
So much so, that 1.5 billion people around the globe are now overweight while 500 million are obese.
Major changes in food supply over the past century, as a result of technological advances and modern farming methods, have distorted the omega 6 to omega 3 fatty acid ratio in the typical Western diet, which developing countries are now also increasingly adopting, say the authors.
The production of vegetable oils high in omega 6, such as sunflower, safflower, and corn oils, has soared, while animal feeds have switched from grass, which contains omega 3, to grain, resulting in higher levels of omega 6 in meat, eggs, and dairy products.
This matters because while the body needs both types of fatty acid, human beings evolved to eat a diet containing equal amounts of omega 6 and omega 3 in it. But that dietary ratio is now a belt-busting 16:1 rather than the healthy 1: 2/1, the authors contend.
Fatty acids act directly on the central nervous system, influencing food intake and the sensitivity of the hormones involved in blood sugar control (insulin) and appetite suppression (leptin).
But too much omega 6 promotes inflammation and is prothrombotic (increasing the risk of blood clotting) as well as boosting production of white fat tissue that is stored rather than 'good' energy-burning brown fat tissue.
And copious amounts of white fat and chronic inflammation are the hallmarks of obesity, the authors point out, as well as being linked to type 2 diabetes, cardiovascular disease, metabolic syndrome, and cancer.
Furthermore, different populations metabolise fatty acids differently, making them more or less vulnerable to the consequences of an imbalance, they add.
They point to several key studies that have shown a strong link between the dietary omega 6 to omega 3 ratio and long term weight gain.
"The time has come to return the omega 3 fatty acids in the food supply and decrease the omega 6 fatty acids by changing the cooking oils and eating less meat and more fish," they write. "The composition of the food supply must also change to be consistent with the evolutionary aspects of diet and the genetics of the population," they add.
"The scientific evidence to balance the omega 6 to omega 3 ratio is robust and necessary for normal growth and development, prevention and treatment of obesity and its comorbidities, including diabetes, cardiovascular disease and cancer," they continue.
And they conclude: "It is the responsibility of governments and international organisations to establish nutrition policies based on science and not continue along the same path of focusing exclusively on calories and energy expenditure, which have failed miserably over the past 30 years."
Cranberry disrupts bacteria associated with problematic and pervasive infections ability to communicate, spread and become virulent
Scientists from McGill University and INRS-Institut Armand-Frappier in Canada recently released a novel investigation showing that cranberry extract successfully interrupted the communication between bacteria associated with problematic and pervasive infections. The authors of the data published in Nature's Scientific Reports, Eric Déziel, professor-investigator at INRS-Institut Armand-Frappier and Nathalie Tufenkji, professor at McGill University, state that not only do the results provide insights into how cranberry compounds may work, they also have implications for the development of alternative approaches to control infections.
Previously published work has shown that the American cranberry (Vaccinium macrocarpon L) contains compounds -- such as proanthocyanidins (PACs) -- that provide meaningful antioxidant, anti-adhesion and anti-microbial properties that help fend off illness. Given this, the scientific team hypothesized that cranberries may also have an anti-virulence potential. They wanted to know if these cranberry compounds could help manage bacterial infections. By feeding fruit flies -- a commonly used model for studying human infections -- cranberry extract, the team discovered that cranberry provided flies protection from a bacterial infection and they lived longer than their cranberry-free counterparts. In essence, the cranberry extract reduced the severity of the bacterial infection.
Study author, Dr. Tufenkji, elaborates on what this might mean for humans, as opposed to flies, "This means that cranberries could be part of the arsenal used to manage infections and potentially minimize the dependence on antibiotics for the global public."
To further explain cranberries' impact on bacteria, Dr. Déziel said, "Cranberry PACs interrupt the ability for bacteria to communicate with each other, spread and become virulent -- a process known as quorum sensing. The cranberry extract successfully interferes with the chain of events associated with the spread and severity of chronic bacterial infections."
Added to the evidence of cranberry's role in preventing recurrent urinary tract infections by blocking bacteria from sticking to cell walls, the current study suggests that PACs may help control the virulence or spread of potentially dangerous bacterial infections around the world.
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The complete study can be accessed here: Cranberry-derived proanthocyanidins impair virulence and inhibit quorum sensing of Pseudomonas aeruginosa.
Protein quality matters when it comes to building muscle
Attention Crossfit®, HIIT, Orange Theory® and absolutely anyone who cares about maintaining muscle mass - Tier 1 Canada Research Chair in Skeletal Muscle Health, Dr. Stuart M. Phillips of MacMaster University, reasons that the quality of protein you consume for muscle building with resistance training may be more important than you realize. In a recent article in Nutrition and Metabolism, Dr. Phillips reviewed the current science to examine the effects of the quality of supplemental protein on changes in muscle mass, strength and body composition when combined with strength training. His comprehensive inquiry suggests that based on the new proposed method to evaluate protein quality using its indispensable (or essential) amino acid composition and its digestibility, protein sources that provide leucine (an essential amino acid) - such as whey protein - are the strongest determinant of muscle protein synthesis and likely muscle growth.
"My assessment of the data on protein supplementation and resistance exercise reveals that the amount of leucine in a protein supplement has the greatest impact on muscle protein synthesis," said, Dr. Phillips. "Leucine is not only a building block for protein, but a trigger for working muscles to synthesize more protein. In essence, it turns on muscle protein synthesis like a light switch so that over time, there could be greater gains in lean body mass and strength, and subsequently, body composition improvements."
Proteins with the greatest content of leucine include whey protein isolate or concentrate. Whey protein is a milk protein that is considered high-quality due to its amino acid profile and high score for digestibility. Based on the culmination of data inspecting protein types and muscle protein synthesis, whey protein rated higher than other protein sources such as soy, pea or rice.
"The outcome of this review isn't just applicable to strength trainers," Dr. Phillips notes. "As we age, muscle loss becomes prevalent if we don't thwart the decline. Leucine-rich whey protein supplementation, combined with resistance exercise, may be one way to help preserve muscle mass throughout the lifespan."
While more research is warranted to further characterize proteins based on their quality, digestibility and amino acid profile, as well as to identify their impact on the aging population - at this point, consumers should reach for a leucine-containing protein supplement, like whey, to maximize gains from hard workouts.
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To read the complete review: http://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-016-0124-8
Toss eggs onto salads to increase Vitamin E absorption
Adding whole eggs to a colorful salad boosts the amount of Vitamin E the body absorbs from the vegetables, according to research from Purdue University.
"Vitamin E is the second-most under-consumed nutrient in the average American diet, which is problematic because this fat-soluble nutrient has antioxidant and anti-inflammatory properties," said Wayne Campbell, a professor of nutrition science. "Now consumers can easily improve their diets by adding eggs to a salad that boasts a variety of colorful vegetables."
Jung Eun Kim, a postdoctoral researcher in Purdue's Department of Nutrition Science, said, "We found Vitamin E absorption was 4- to 7-fold higher when three whole eggs were added to a salad. This study is novel because we measured the absorption of Vitamin E from real foods, rather than supplements, which contain mega-dose amounts of Vitamin E."
Vitamin E, which is absorbed along with dietary fats, is often found in oils, seeds and nuts. Eggs, a nutrient-rich food containing essential amino acids, unsaturated fatty acids and B vitamins, also contain a small amount of Vitamin E. This study accounted for how much total Vitamin E was absorbed when Vitamin E containing foods were co-consumed with whole eggs. This research supports a way to increase the absorption of Vitamin E found in foods that contain low dietary fat. Also, this research highlights how one food can improve the nutrition value of another food when they are consumed together.
The findings are published in The Journal of Nutrition, and the study was supported by the American Egg Board's Egg Nutrition Center, National Institutes of Health and Purdue Ingestive Behavior Research Center.
This research is an extension of a study that Campbell and Kim, along with Mario Ferruzzi, a professor at North Carolina State University, reported in June 2015 showing that by adding eggs to a salad there was an overall increased absorption of the vegetables' carotenoids. Both studies had 16 participants consume a raw mixed-vegetable salad with no eggs, a salad with one and a half eggs, and a salad with three eggs, 0 grams, 75 grams and 150 grams of eggs, respectively. All salads were served with three grams of canola oil, and the eggs were served scrambled to ensure the whole egg was consumed. In the 2015 study, the absorption of carotenoids - including alpha-carotene, beta-carotene, lutein, zeaxanthin and lycopene - was 3- to 8-fold higher when the salad included three eggs compared to no eggs.
Previous research conducted by Campbell and Ferruzzi also has shown that more carotenoids are absorbed when one larger salad is consumed at a meal, compared to smaller salads consumed at two meals during the day.
Saturday, October 22, 2016
My Diet
I eat a basically
Mediterranean diet (Health Benefits of a Mediterranean Diet)
with lots! of olive oil and nuts (Health Benefits of Olive Oil and Nuts).
For breakfast:
oats and barley (Health Benefits of Oatmeal and Barley)
with blueberries or strawberries. (Health Benefits of Blueberries and Strawberries)
or one or two eggs (Health Benefits of Eggs)
For lunch:
dark greens (Health Benefits of Leafy Green Vegetables)
with tomatoes and peppers-red, green,orange, yellow(Health Benefits of Tomatoes and Peppers)
and anchovies! -sometimes with a gefilte fish chaser.
My dinners have a base of onions
brocoli, cauliflower,red cabbage (Health Benefits of Cruciferous Vegetables: broccoli, cabbage and cauliflower)
and carrots
with a variety of add-ons including tomato sauce,
a large variety of Goya Beans,peas,and green beans (Health Benefits of beans, peas, chickpeas and lentils)
seafood, brown rice and chicken.
I try to have a glass of red wine or a bottle of beer every evening, (Health Benefits of Moderate Alcohol Consumption)
and dark chocolate for dessert.(Health Benefits of Chocolate)
I also drink a lot of coffee (Health Benefits of Coffee)
and white tea. (Health Benefits of White and Green Tea Consumption)
Health Benefits of Oatmeal and Barley
Health Benefits of Fiber: Overall Health
Eating barley or foods containing barley significantly reduced levels
of two types of "bad cholesterol" associated with cardiovascular risk, a
St. Michael's Hospital research paper has found.
Barley reduced both low-density lipoprotein, or LDL, and non-high-density lipoprotein, or non-HDL, by seven per cent. The review also indicated that barley had similar cholesterol-lowering effects as oats, which is often the go-to grain for health benefits. The research review, published today in The European Journal of Clinical Nutrition, included 14 studies on clinical trials conducted in seven countries, including Canada. It is the first study to look at the effects of barley and barley products on both LDL and non-HDL cholesterol in addition to apolipoprotein B, or apoB, a lipoprotein that carries bad cholesterol through the blood. Measuring non-HDL and apoB provides a more accurate assessment for cardiovascular risk, as they account for the total 'bad cholesterol' found in the blood. "The findings are most important for populations at high risk for cardiovascular disease, such as Type 2 diabetics, who have normal levels of LDL cholesterol, but elevated levels of non-HDL or apo B," said Dr. Vladimir Vuksan, research scientist and associate director of the Risk Factor Modification Centre of St. Michael's. "Barley has a lowering effect on the total bad cholesterol in these high-risk individuals, but can also benefit people without high cholesterol." High cholesterol and diabetes are major risk factors for cardiovascular disease and stroke, historically treated with medications. However, Dr. Vuksan's research and work focuses on how dietary and lifestyle changes can reduce these risk factors. "Barley's positive effect on lowering cholesterol is well-documented and has been included in the Canadian strategy for reducing cardiovascular risk," said Dr. Vuksan. "Health Canada, the FDA and several health authorities worldwide have already approved health claims that barley lowers LDL cholesterol, but this is the first review showing the effects on other harmful lipids." Despite its benefits Dr. Vuksan said barley is not as well-established as some other health-recommended foods -- such as oats. Barley consumption by humans has fallen by 35 per cent in the last 10 years. Canada is one of the top five world producers of barley -- almost 10 megatonnes per year -- but human consumption accounts for only two per cent of the crop yield, with livestock making up the other 98 per cent. "After looking at the evidence, we can also say that barley is comparably effective as oats in reducing overall risk of cardiovascular disease" said Dr. Vuksan. Barley is higher in fibre, has twice the protein and almost half the calories of oats, which are important considerations for those with weight or dietary concerns. Dr. Vuksan said barley can be enjoyed in a variety of ways. He recommends trying to incorporate barley into existing recipes, using it as a substitute for rice or even on its own -- just like oatmeal. Barley can help improve blood sugar levels and reduce appetiteA recent study from Lund University in Sweden shows that barley can rapidly improve people's health by reducing blood sugar levels and risk for diabetes. The secret lies in the special mixture of dietary fibres found in barley, which can also help reduce people's appetite and risk for cardiovascular disease. "It is surprising yet promising that choosing the right blend of dietary fibres can -- in a short period of time -- generate such remarkable health benefits", says Anne Nilsson, Associate Professor at the Food for Health Science Centre and one of the researchers behind the study. The study was conducted with healthy middle-aged participants who were asked to eat bread largely made out of barley kernels (up to 85%) for three days -- at breakfast, lunch and dinner. Approximately 11-14 hours after their final meal of the day participants were examined for risk indicators of diabetes and cardiovascular disease. The researchers found that the participants' metabolism improved for up to 14 hours, with additional benefits such as decreases in blood sugar and insulin levels, increases in insulin sensitivity and improved appetite control. The effects arise when the special mixture of dietary fibres in barley kernel reaches the gut, stimulating the increase of good bacteria and the release of important hormones. "After eating the bread made out of barley kernel, we saw an increase in gut hormones that regulate metabolism and appetite, and an increase in a hormone that helps reduce chronic low-grade inflammation, among the participants. In time this could help prevent the occurrence of both cardiovascular disease and diabetes", says Anne Nilsson. In a previous related study conducted with a team from the University of Gothenburg in Sweden researchers also found that dietary fibres from barley kernel generate an increase of the gut bacteria Prevotella copri, which have a direct regulatory effect on blood sugar levels and help decrease the proportion of a type of gut bacteria that is considered unhealthy. The effects from barley kernel are influenced by the composition of the individual's gut microbiota, meaning people with low concentrations of the Prevotella copri bacteria experienced less effect from their intake of barley products. Eating more barley could, however, help stimulate growth of the bacteria. The results are timely as rates of obesity and type 2 diabetes have significantly increased in the past few years. Researchers hope that more knowledge about the impact of specific dietary fibres on people's health will result in stores keeping more food products with healthy properties such as barley kernels. The ambition is also to get more people to use barley in meals, for example in salads, soups, stews, or as an alternative to rice or potatoes. The researchers' advice for how to maintain a healthy blood sugar level:
The bread used in the study was 85% made out of barley grains, which had been boiled and mixed with wheat flour. If you want to reduce the amount of barley grains, you can replace some of it with whole grains. |
Health Benefits of Oatmeal: Appetite
Oatmeal for breakfast results in greater fullness and lower calorie intake at lunch
A new study suggests that your breakfast cereal choice may affect how full you feel and how much you eat for lunch, especially if you're overweight. According to new research published in the latest issue of the Annals of Nutrition and Metabolism, scientists found that having oatmeal (Quaker Oats Quick 1-minute™) for breakfast resulted in greater fullness, lower hunger ratings and fewer calories eaten at the next meal compared to a calorie-matched breakfast of a ready-to-eat cereal (RTEC) - sugared corn flakes.
Scientists from the New York Obesity Nutrition Research Center at Mount Sinai St. Luke's Hospital randomly assigned 36 subjects (18 normal weight and 18 overweight) to each receive three different breakfasts. The breakfasts consisted of 350 calories of similar amounts of carbohydrates, fat and liquid from either quick-cook oatmeal or sugared corn flakes. A third control breakfast was only 1.5 cups of water. To evaluate appetite, ratings of hunger and fullness were obtained at frequent intervals before and after the breakfast until a lunch test meal 3 hours later. Researchers measured the calorie intake of the lunch meal consumed to compare the effects of the corn flakes, oatmeal or water breakfasts. Blood samples were collected just after each of the appetite ratings to assess levels of glucose, insulin, acetaminophen (a marker for how quickly the breakfast emptied from the stomach into the intestine) and various hormones related to appetite, in response to each breakfast.
"Our results show that despite eating the same number of calories at breakfast, satiety values were significantly greater after consuming oatmeal compared to sugared corn flakes. After three hours, subjects reported the same level of hunger after having a corn flakes breakfast as they did when they consumed only water," explained lead researcher Allan Geliebter, PhD, research psychologist in the Department of Psychiatry at Mount Sinai St. Luke's Hospital. "Interestingly, the results were more pronounced for the participants who were overweight, suggesting that overweight individuals may be more responsive to the satiety effects of the dietary fiber in oatmeal."
The results showed statistically significant higher ratings of fullness, lower ratings of hunger, and 31% fewer calories consumed at lunch after consuming oatmeal compared to sugared corn flakes or water. The overall satiety effect was greater among overweight subjects, who consumed 50% fewer calories at lunch after eating oatmeal.
The study authors suggested that the greater satiety effect of oatmeal cereal compared to sugared corn flakes or water might be due to a slower gastric emptying (oatmeal took longer to leave the stomach). Given that the results were more pronounced in overweight subjects, researchers suggested that a longer-term weight control study testing daily oatmeal for breakfast is warranted.
A new study revealed that your cereal choice at breakfast might have an impact on how much you eat for lunch. Newly published research in the Journal of the American College of Nutrition showed that a hearty bowl of instant oatmeal helped curb food intake at lunch better than a leading oat-based, cold cereal -- even when each bowl provided the same number of calories.
The statistically significant results of the randomized, controlled crossover study (n=47) showed that a 250-calorie instant oatmeal serving (with an additional 113 calories of skim milk) enhanced satiety and feelings of fullness, reduced the desire to eat and may even lead to a lower caloric intake at lunch, compared to a 250-calorie serving of cold, oat-based cereal, also served with an additional 113 calories of skim milk.
"The satiety benefits of instant oatmeal alone were important findings," remarked lead author Candida Rebello, MS, RD, of Pennington Biomedical Research Center at Louisiana State University. "When we took it a step further and evaluated the intake four hours post-breakfast, we found that after consuming instant oatmeal, the participants chose to eat significantly less at lunch compared to those who ate the oat-based, cold cereal."
After an analysis of the types of fiber in each cereal, the researchers suspected that the higher molecular viscosity of the beta-glucan in the instant oatmeal contributed to its satiating effect over the oat-based, cold cereal. Authors stated that the processing of the cold cereal might lead to changes in the oat fiber that reduced its ability to enhance satiety.
Researchers presented the participants with a lunch meal of their choice - turkey, ham, roast beef or vegetable patty sandwiches and a calorie-free or calorie-containing beverage, alongside potato crisps and cookies. The lunches offered ranged from 2,600 to 2,800 calories and participants were told to "eat to satisfaction." Total calorie intake was significantly lower following consumption of instant oatmeal compared to the cold cereal, as were fat and protein intake. Grams of carbohydrate and total weight of the foods were not significantly different.
Health Benefits of Coffee-Miscellaneous and Comprehensive
Benefits of drinking coffee outweigh risks
Coffee is enjoyed by millions of people every
day and the 'coffee experience' has become a staple of our modern life
and culture. While the current body of research related to the effects
of coffee consumption on human health has been contradictory, a study in
the June issue of Comprehensive Reviews in Food Science and Food Safety,
which is published by the Institute of Food Technologists (IFT), found
that the potential benefits of moderate coffee drinking outweigh the
risks in adult consumers for the majority of major health outcomes
considered.
The review was used to create an exhaustive list of the potential health benefits and risks of coffee consumption on the following health outcomes:
- Total Mortality
- Cardiovascular Disease
- Cancer
- Metabolic Health
- Neurological Disorders
- Gastrointestinal Conditions
- Other Miscellaneous Health Outcomes
The authors noted causality of risks and benefits cannot be established for either with the research currently available as they are largely based on observational data. Further research is needed to quantify the risk-benefit balance for coffee consumption, as well as identify which of coffee's many active ingredients, or indeed the combination of such, that could be inducing these health benefits.
Moderate coffee drinking reduces many risks
Although the American Society for Nutrition’s popular “controversy session” at Experimental Biology 2007 focuses on the health effects of coffee drinking, panel chair Dr. James Coughlin, a toxicology/safety consultant at Coughlin & Associates, says that recent advances in epidemiologic and experimental knowledge have transformed many of the negative health myths about coffee drinking into validated health benefits.
Indeed, panel co-chair Dan Steffen, who follows coffee and health issues in the Scientific and Regulatory Affairs group of Kraft Foods, note that the “controversy” is often to educate a wider audience about this transformation in understanding.
Coffee is among the most widely consumed beverages in the world, and Dr. Coughlin says that the preponderance of scientific evidence - some by the panelists - suggests that moderate coffee consumption (3-5 cups per day) may be associated with reduced risk of certain disease conditions, such as Parkinson’s disease. Some research in neuropharamacology suggests that one cup of coffee can halve the risk of Parkinson’s disease. Other studies have found it reduces the risk of Alzheimer's disease, kidney stones, gallstones, depression and even suicide.
Dr. Coughlin and two distinguished researchers discussed some of the benefits - and a couple of the remaining increased risk factors (possible increase in blood pressure and plasma homocysteine) - on April 30 at the Experimental Biology meeting in Washington, DC.
Dr. Rob van Dam, an epidemiologist at the Harvard School of Public Health and the Harvard Medical School, studies the link between diet and the development of type 2 diabetes. Worldwide, an estimated 171 million persons have diabetes, mostly type 2 diabetes, and an alarming increase to 366 million persons is expected for the year 2030. While increased physical activity and restriction of energy intake can substantially reduce risk of type 2 diabetes, he believes insight into the role of other lifestyle factors may contribute to additional prevention strategies for type 2 diabetes.
In recent epidemiological studies in the U.S., Europe and Japan, persons who were heavy coffee consumers had a lower risk of type 2 diabetes than persons who consumed little coffee. Interestingly, he says, associations were similar for caffeinated and decaffeinated coffee, suggesting that coffee components other than caffeine may be beneficial for glucose metabolism.
Coffee contains hundreds of components including substantial amounts of chlorogenic acid, caffeine, magnesium, potassium, vitamin B3, trigonelline, and lignans. Limited evidence suggests that coffee may improve glucose metabolism by reducing the rate of intestinal glucose absorption and by stimulating the secretion of the gut hormone glucagon-like peptide-1 (GLP-1) that is beneficial for the secretion of insulin. However, most mechanistic research on coffee and glucose metabolism has been done in animals and in lab tubes and therefore metabolic studies in humans are currently being conducted. Further research may lead to the development or selection of coffee types with improved health effects.
Dr. Lenore Arab, a nutritional epidemiologist in the David Geffen School of Medicine at UCLA, notes that the first coffee controversy dates back 430 years when in 1570 some monks petitioned the pope to condemn this drink, so popular among Muslims. Pope Clement VIII, liking how it kept the monks from falling sleep during mass, purportedly blessed it instead. The rest, including the United States’ wholesale conversion to coffee following the Boston Tea Party, is history.
In reviewing the latest epidemiologic literature on cancers and coffee, Dr. Arab has found there to be close to 400 studies of the associations between coffee consumption and cancers various at various sites. The earlier controversy with regard to colon cancer was based on flawed analyses, she says. More thorough analyses and the accumulation of evidence suggest no negative effect on the incidence of colon cancer, and possible protective effects for adenomas of the colon as well as for rectal cancer and liver cancer. Mechanisms which might contribute to a possible anticarcinogenic effect include reduction in cholesterol, bile acid and neutral sterol secretion in the colon, increased colonic motility and reduced exposure of epithelium to carcinogens, the ability of diterpenes to reduce genotoxicity of carcinogens, and lower DNA adduct formation, and the ability of caffeic acid and chlorogenic acid to decreased DNA methylation. In other cancers - breast, ovarian, and prostate - the evidence is not suggestive of either risk or protection. There are two areas, says Dr. Arab, in which there is some evidence of increased risk: leukemia and stomach cancer. The evidence for the former is intriguing, for the latter insubstantial. She concludes that a systematic review of the newer data for liver, rectal, stomach cancer and for childhood leukemia is due.
Caffeine intake associated with reduced levels of erectile dysfunction
Men who drink the equivalent caffeine level of two to three cups of coffee a day are less likely to have erectile dysfunction (ED), according to researchers from The University of Texas Health Science Center at Houston (UTHealth).
The results of a study published (May 2015) in PLOS ONE found that men who consumed between 85 and 170 milligrams of caffeine a day were 42 percent less likely to report ED, while those who drank between 171 and 303 milligrams of caffeine a day were 39 percent less likely to report ED compared to those who drank zero to seven milligrams a day. This trend was also true among overweight, obese and hypertensive men.
"Even though we saw a reduction in the prevalence of ED with men who were obese, overweight and hypertensive, that was not true of men with diabetes. Diabetes is one of the strongest risk factors for ED, so this was not surprising," said David S. Lopez, Dr.P.H., M.P.H., lead author and assistant professor at UTHealth School of Public Health.
According to the journal article, the suggested biological mechanism is that caffeine triggers a series of pharmacological effects that lead to the relaxation of the penile helicine arteries and the cavernous smooth muscle that lines cavernosal spaces, thus increasing penile blood flow.
In the United States, 18.4 percent of men 20 years and older have ED, suggesting that more than 18 million men are affected. Caffeine is consumed by more than 85 percent of adults, according to previous research.
Data for the study came from the National Health and Nutrition Examination Survey and ED was assessed by a single question during a computer-assisted interview. Caffeine sources in the study included coffee, tea, soda and sports drinks.
New evidence that caffeine is a healthful antioxidant in coffee
Scientists are reporting an in-depth analysis of how the caffeine in coffee, tea, and other foods seems to protect against conditions such as Alzheimer's disease and heart disease on the most fundamental levels. The report, which describes the chemistry behind caffeine's antioxidant effects, appears in ACS' The Journal of Physical Chemistry.
Annia Galano and Jorge Rafael León-Carmona describe evidence suggesting that coffee is one of the richest sources of healthful antioxidants in the average person's diet. Some of the newest research points to caffeine (also present in tea, cocoa, and other foods) as the source of powerful antioxidant effects that may help protect people from Alzheimer's and other diseases. However, scientists know little about exactly how caffeine works in scavenging the so-called free radicals that have damaging effects in the body. And those few studies sometimes have reached contradictory conclusions.
In an effort to bolster scientific knowledge about caffeine, they present detailed theoretical calculations on caffeine's interactions with free radicals. Their theoretical conclusions show "excellent" consistency with the results that other scientists have report from animal and other experiments, bolstering the likelihood that caffeine is, indeed, a source of healthful antioxidant activity in coffee.
Drinking coffee may be associated with a lower risk of developing multiple sclerosis
Drinking
coffee may be associated with a lower risk of developing multiple
sclerosis (MS), according to a study released today that will be
presented at the American Academy of Neurology's 67th Annual Meeting in
Washington, DC, April 18 to 25, 2015.
"Caffeine intake has been associated with a reduced risk of
Parkinson's and Alzheimer's diseases, and our study shows that coffee
intake may also protect against MS, supporting the idea that the drug
may have protective effects for the brain," said study author Ellen
Mowry, MD, MCR, with Johns Hopkins University School of Medicine in
Baltimore and a member of the American Academy of Neurology.For the study, researchers looked at a Swedish study of 1,629 people with MS and 2,807 healthy people, and a U.S. study of 1,159 people with MS and 1,172 healthy people. The studies characterized coffee consumption among persons with MS one and five years before MS symptoms began (as well as 10 years before MS symptoms began in the Swedish study) and compared it to coffee consumption of people who did not have MS at similar time periods. The study also accounted for other factors such as age, sex, smoking, body mass index, and sun exposure habits.
The Swedish study found that compared to people who drank at least six cups of coffee per day during the year before symptoms appeared, those who did not drink coffee had about a one and a half times increased risk of developing MS. Drinking large amounts of coffee five or 10 years before symptoms started was similarly protective.
In the US study, people who didn't drink coffee were also about one and a half times more likely to develop the disease than those who drank four or more cups of coffee per day in the year before symptoms started to develop the disease.
"Caffeine should be studied for its impact on relapses and long-term disability in MS as well," said Mowry.
Drinking coffee may reduce the risk of liver cirrhosis
Regular consumption of coffee was linked with a reduced risk of liver cirrhosis in a review of relevant studies published before July 2015.
In patients with cirrhosis, the liver becomes scarred often as a result of long-term and persistent injury from toxins like alcohol and viruses like hepatitis C. It can be fatal because it increases the risk of liver failure and cancer.
The analysis found that an extra 2 cups of coffee per day may reduce the risk of cirrhosis by 44%, and it may nearly halve the risk of dying from cirrhosis.
"Coffee appeared to protect against cirrhosis.This could be an important finding for patients at risk of cirrhosis to help to improve their health outcomes," said Dr. O. J. Kennedy, lead author of the analysis in the journal Alimentary Pharmacology and Therapeutics. "However, we now need robust clinical trials to investigate the wider benefits and harms of coffee so that doctors can make specific recommendations to patients."
Caffeine consumption = decreased risk of liver disease
Caffeine consumption has long been associated with decreased risk of liver disease and reduced fibrosis in patients with chronic liver disease. Now, newly published research confirms that coffee caffeine consumption reduces the risk of advanced fibrosis in those with nonalcoholic fatty liver disease (NAFLD). Findings published in the February, 2012 issue of Hepatology, a journal of the American Association for the Study of Liver Diseases, show that increased coffee intake, specifically among patients with nonalcoholic steatohepatitis (NASH), decreases risk of hepatic fibrosis.
The steady increase in rates of diabetes, obesity, and metabolic syndrome over the past 20 years has given rise to greater prevalence of NAFLD. In fact, experts now believe NAFLD is the leading cause of chronic liver disease in the U.S., surpassing both hepatitis B and C. The majority of patients will have isolated fatty liver which has a very low likelihood of developing progressive liver disease. However, a subset of patients will have NASH, which is characterized by inflammation of the liver, destruction of liver cells, and possibly scarring of the liver. Progression to cirrhosis (advanced scarring of the liver) may occur in about 10-11% of NASH patients over a 15 year period, although this is highly variable.
To enhance understanding of the correlation between coffee consumption and the prevalence and severity of NAFLD, a team led by Dr. Stephen Harrison, Lieutenant Colonel, U.S. Army at Brooke Army Medical Center in Fort Sam Houston, Texas surveyed participants from a previous NAFLD study as well as NASH patients treated at the center's hepatology clinic. The 306 participants were asked about caffeine coffee consumption and categorized into four groups: patients with no sign of fibrosis on ultrasound (control), steatosis, NASH stage 0-1, and NASH stage 2-4.
Researchers found that the average milligrams in total caffeine consumption per day in the control, steatosis, Nash 0-1, and Nash 2-4 groups was 307, 229, 351 and 252; average milligrams of coffee intake per day was 228, 160, 255, and 152, respectively. There was a significant difference in caffeine consumption between patients in the steatosis group compared to those with NASH stage 0-1. Coffee consumption was significantly greater for patients with NASH stage 0-1, with 58% of caffeine intake from regular coffee, than with NASH stage 2-4 patients at only 36% of caffeine consumption from regular coffee.
Multiple analyses showed a negative correlation between coffee consumption and risk of hepatic fibrosis. "Our study is the first to demonstrate a histopatholgic relationship between fatty liver disease and estimated coffee intake," concludes Dr. Harrison. "Patients with NASH may benefit from moderate coffee consumption that decreases risk of advanced fibrosis. Further prospective research should examine the amount of coffee intake on clinical outcomes."
Increased Caffeinated Coffee Consumption Associated With Decreased Risk of Depression in Women
The risk of depression appears to decrease for women with increasing consumption of caffeinated coffee, according to a report in the September 26, 2011 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Caffeine is the most frequently used central nervous system stimulant in the world, and approximately 80 percent of consumption is in the form of coffee, according to background information in the article. Previous research, including one prospective study among men, has suggested an association between coffee consumption and depression risk. Because depression is a chronic and recurrent condition that affects twice as many women as men, including approximately one of every five U.S. women during their lifetime, “identification of risk factors for depression among women and the development of new preventive strategies are, therefore, a public health priority,” write the authors. They sought to examine whether, in women, consumption of caffeine or certain caffeinated beverages is associated with the risk of depression.
Michel Lucas, Ph.D., R.D., from the Harvard School of Public Health, Boston, and colleagues studied 50,739 U.S. women who participated in the Nurses’ Health Study. Participants, who had a mean (average) age of 63, had no depression at the start of the study in 1996 and were prospectively followed up with through June 2006. Researchers measured caffeine consumption through questionnaires completed from May 1980 through April 2004, including the frequency that caffeinated and noncaffeinated coffee, nonherbal tea, caffeinated soft drinks (sugared or low-calorie colas), caffeine-free soft drinks (sugared or low-calorie caffeine-free colas or other carbonated beverages) and chocolate were usually consumed in the previous 12 months. The authors defined depression as reporting a new diagnosis of clinical depression and beginning regular use of antidepressants in the previous two years.
Analysis of the cumulative mean consumption included a two-year latency period; for example, data on caffeine consumption from 1980 through 1994 were used to predict episodes of clinical depression from 1996 through 1998; consumption from 1980 through 1998 were used for the 1998 through 2000 follow-up period; and so on. During the 10-year follow-up period from 1996 to 2006, researchers identified 2,607 incident (new-onset) cases of depression. When compared with women who consumed one cup of caffeinated coffee or less per week, those who consumed two to three cups per day had a 15 percent decrease in relative risk for depression, and those consuming four cups or more per day had a 20 percent decrease in relative risk. Compared with women in the lowest (less than 100 milligrams [mg] per day) categories of caffeine consumption, those in the highest category (550 mg per day or more) had a 20 percent decrease in relative risk of depression. No association was found between intake of decaffeinated coffee and depression risk.
“In this large prospective cohort of older women free of clinical depression or severe depressive symptoms at baseline, risk of depression decreased in a dose-dependent manner with increasing consumption of caffeinated coffee,” write the authors. They note that this observational study “cannot prove that caffeine or caffeinated coffee reduces the risk of depression but only suggests the possibility of such a protective effect.” The authors call for further investigations to confirm their results and to determine whether usual caffeinated coffee consumption could contribute to prevention or treatment of depression/
Coffee W/O Milk Fights Bad Breath
We all know why Starbucks puts boxes of breath mints close to the cash register. Your morning latte can create a startling aroma in your mouth, strong enough to startle your co-workers too.
But intriguing research from Tel Aviv University by renowned breath specialist Prof. Mel Rosenberg of TAU's Sackler Faculty of Medicine finds that a coffee extract can inhibit the bacteria that lead to bad breath. laboratory tests have shown that the extract prevents malodorous bacteria from making their presence felt — or smelt.
"Everybody thinks that coffee causes bad breath," says Prof. Rosenberg, "and it's often true, because coffee, which has a dehydrating effect in the mouth, becomes potent when mixed with milk, and can ferment into smelly substances."
But not always. "Contrary to our expectations, we found some components in coffee that actually inhibit bad breath," explains Prof. Rosenberg.
In the laboratory, the team monitored the bacterial odor production of coffee in saliva. In the study, three different brands of coffee were tested: the Israeli brand Elite coffee, Landwer Turkish coffee, and Taster's Choice. Prof. Rosenberg expected to demonstrate the malodor-causing effect of coffee in an in vitro saliva assay developed by Dr. Sarit Levitan in his laboratory. To his surprise, the extracts had the opposite effect.
"The lesson we learned here is one of humility," says Prof. Rosenberg. "We expected coffee would cause bad breath, but there is something inside this magic brew that has the opposite effect."
Prof. Rosenberg would love to isolate the bacterial-inhibiting molecule in order to reap the biggest anti-bacterial benefits from coffee. "It's not the raw extract we will use, he says, "but an active material within it." His latest discovery could be the foundation for an entirely class of mouthwash, breath mints and gum. Purified coffee extract can be added to a breath mint to stop bacteria from forming, stopping bad breath at its source, instead of masking the smell with a mint flavor.
Prof. Rosenberg is a successful scientist and inventor who has already developed a popular mouthwash sold widely in Europe, a pocket-based breath test, and an anti-odor chewing gum.
Coffee consumption may lower blood uric acid levels
High uric acid levels in the blood are a precursor of gout, the most common inflammatory arthritis in adult men. It is believed that coffee and tea consumption may affect uric acid levels but only one study has been conducted to date. A large-scale study published in the June 2007 issue of Arthritis Care & Research (http://www.interscience.wiley.com/journal/arthritiscare) examined the relationship between coffee, tea, caffeine intake, and uric acid levels and found that coffee consumption is associated with lower uric acid levels but that this appears to be due to components other than caffeine.
Coffee is one of the most widely consumed beverages in the world; more than 50 percent of Americans drink it at the average rate of 2 cups per day. Because of this widespread consumption, its potential effects have important implications for public and individual health. Led by Hyon K. Choi, of the University of British Columbia in Vancouver, Canada, the current study was based on the U.S. Third National Health and Nutrition Examination Survey, conducted between 1988 and 1994. It included over 14,000 men and women at least 20 years old who consented to a medical exam in which blood and urine specimens were obtained. Coffee and tea consumption were determined based on responses to a food questionnaire that assessed intake over the previous month. Researchers estimated the amount of caffeine per cup of coffee or tea using data from the U.S. Department of Agriculture.
The results showed that levels of uric acid in the blood significantly decreased with increasing coffee intake, but not with tea intake. In addition, there was no association between total caffeine intake from beverages and uric acid levels. These results were similar to those found in the only previous study on the topic, which was conducted in Japan. Interestingly, there was an association between decaffeinated coffee consumption and uric acid levels. "These findings suggest that components of coffee other than caffeine contribute to the observed inverse association between coffee intake and uric acid levels," the researchers state.
A recent study found that coffee was associated lower C peptide levels (a marker of insulin levels). The researchers in the current study suggest that because there is a strong relationship between insulin resistance and elevated uric acid levels, the decreased insulin levels associated with coffee consumption may lead to lower uric acid levels. Coffee is also a major source of chlorogenic acid, a strong antioxidant, which may improve insulin sensitivity. Chlorogenic acid also helps inhibit glucose absorption in the intestine; in another study decaffeinated coffee seemed to delay intestinal absorption of glucose and increase concentrations of glucagon-like peptide 1, which is well known for its beneficial effects on insulin secretion and action. The researchers note further that their results could be due to an effect of non-caffeine components found in coffee, which would also explain why coffee affected uric acid levels but tea did not.
To examine how coffee consumption might aggravate or protect against this common and excruciatingly painful condition, researchers at the Arthritis Research Centre of Canada, University of British Columbia in Canada, Brigham and Women’s Hospital, Harvard Medical School, and Harvard School of Public Health in Boston conducted a prospective study on 45,869 men over age 40 with no history of gout at baseline. Over 12 years of follow-up, Hyon K. Choi, MD, DrPH, and his associates evaluated the relationship between the intake of coffee and the incidence of gout in this high risk population. Their findings, featured in the June 2007 issue of Arthritis & Rheumatism (http://www.interscience.wiley.com/journal/arthritis), provide compelling evidence that drinking 4 or more cups of coffee a day dramatically reduces the risk of gout for men.
Subjects were drawn from an ongoing study of some 50,000 male health professionals, 91 percent white, who were between 40 and 75 years of age in 1986 when the project was initiated. To assess coffee and total caffeine intake, Dr. Choi and his team used a food-frequency questionnaire, updated every 4 years. Participants chose from 9 frequency responses – ranging from never to 2 to 4 cups per week to 6 or more per day – to record their average consumption of coffee, decaffeinated coffee, tea, and other caffeine-containing comestibles, such as cola and chocolate.
Through another questionnaire, the researchers documented 757 newly diagnosed cases meeting the American College of Rheumatology criteria for gout during the follow-up period. Then, they determined the relative risk of incident gout for long-term coffee drinkers divided into 4 groups – less than 1 cup per day, 1 to 3 cups per day, 4 to 5 cups per day, and 6 or more cups per day – as well as for regular drinkers of decaffeinated coffee, tea, and other caffeinated beverages. They also evaluated the impact of other risk factors for gout – body mass index, history of hypertension, alcohol use, and a diet high in red meat and high-fat dairy foods among them – on the association between coffee consumption and gout among the study participants.
Most significantly, the data revealed that the risk for developing gout decreased with increasing coffee consumption. The risk of gout was 40 percent lower for men who drank 4 to 5 cups a day and 59 percent lower for men who drank 6 or more cups a day than for men who never drank coffee. There was also a modest inverse association with decaffeinated coffee consumption. These findings were independent of all other risk factors for gout. Tea drinking and total caffeine intake were both shown to have no effect on the incidence of gout among the subjects. On the mechanism of these findings, Dr. Choi speculates that components of coffee other than caffeine may be responsible for the beverage’s gout-prevention benefits. Among the possibilities, coffee contains the phenol chlorogenic acid, a strong antioxidant.
While not prescribing 4 or more cups a day, this study can help individuals make an informed choice regarding coffee consumption. "Our findings are most directly generalizable to men age 40 years and older, the most gout-prevalent population, with no history of gout," Dr. Choi notes. "Given the potential influence of female hormones on the risk of gout in women and an increased role of dietary impact on uric acid levels among patients with existing gout, prospective studies of these populations would be valuable."
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