Tuesday, February 28, 2017
The risk of acute myocardial infarction for the elderly living in and around small cities is increased by air pollution caused by biomass burning from woodstoves.
It is well documented that air pollution in big cities causes heart and lung problems. But what are its consequences on people in smaller urban centres?
By comparing pollution data from three cities in British Columbia (Prince George, Kamloops and Courtenay/Comox) with hospital admissions, researchers from McGill and Health Canada found that rising concentrations of fine particulate air pollution caused by wood burning were associated with increased hospitalization for myocardial infarction. During the cold season, when pollution from woodstoves is at its highest, the risk of heart attacks among subjects of 65 years and older increased by 19%.
"We noticed that the association was stronger when more of the air pollution came from wood burning, says McGill University professor Scott Weichenthal, lead author of a new study published in Epidemiology. This suggests that the source of pollution matters and that all particulate air pollution is perhaps not equally harmful when it comes to cardiovascular disease."
Improving public health
Scott Weichenthal thinks the findings might push cities across Canada to tackle air pollution caused by fireplaces and woodstoves. Increasing winter smog alerts have prompted cities such as Montreal to bring forward bylaws forcing homeowners to register and, eventually, replace their stoves with cleaner sources of heating. The study, says Weichenthal, gives credence to "initiatives aimed at reducing air pollution from residential wood burning in the interest of public health."
Monday, February 27, 2017
Flashbacks of scenes from traumatic events often haunt those suffering from psychiatric conditions, such as Post Traumatic Stress Disorder (PTSD). "The close relationship between the human imagery system and our emotions can cause deep emotional perturbations", says Dr Svetla Velikova of Smartbrain in Norway. "Imagery techniques are often used in cognitive psychotherapy to help patients modify disturbing mental images and overcome negative emotions." Velikova and her team set out to see if such techniques could become self-guided and developed at home, away from the therapist's chair.
Healthy people are also emotionally effected by what we see and the images we remember. Velikova explains, "if we visually remember an image from an unpleasant interaction with our boss, this can cause an increased level of anxiety about our work and demotivation." There is great interest in ways to combat such everyday negative emotional responses through imagery training. But she warns, "this is a challenging task and requires a flexible approach. Each day we face different problems and a therapist teaches us how to identify topics and strategies for imagery exercises."
To find out if we can train ourselves to use imagery techniques and optimize our emotional state, Velikova and co-workers turned to 30 healthy volunteers. During a two-day workshop the volunteers learnt a series of imagery techniques. They learnt how to cope with negative emotions from past events through imagery transformation, how to use positive imagery for future events or goals, and techniques to improve social interactions and enhance their emotional balance in daily life. They then spent the next 12 weeks training themselves at home for 15-20 minutes a day, before attending another similar two-day workshop.
Velikova compared the results of participant psychological assessment and brain activity, or electroencephalographic (EEG), measurement, before and after the experiment. "The psychological testing showed that depressive symptoms were less prominent. The number of those with subthreshold depression, expressing depressive symptoms but not meeting the criteria for depression, was halved. Overall, volunteers were more satisfied with life and perceived themselves as more efficient" she explains.
Following analysis, the EEG data showed significant changes in the beta activity in the right medial prefrontal cortex of the brain. Velikova notes that this region is known to be involved in imaging pleasant emotions and contributing to the degree of satisfaction with life. There were also changes in the functional connectivity of the brain, including increased connectivity between the temporal regions from both hemispheres, which Velikova attributes to enhanced coordination of networks linked to processing of images. She concludes, "this combination of EEG findings also suggests a possible increase in the activity of GABA (gamma -aminobutyric acid), well known for its anti-anxiety and antidepressant properties."
Velikova and co-workers' results indicate that self-guided emotional imagery training has great potential to improve the everyday emotional wellbeing in healthy people. The team is now further exploring how the approach affects the cognitive function of healthy people. With minimal professional intervention, this technique could be developed to be a cost-effective aid for those with subthreshold depression. It could also be promoted by businesses to help improve workforce morale and drive up productivity.
After a heart attack, it is important for patients to take medication that lowers cholesterol levels. In a new study published in the European Journal of Preventive Cardiology, researchers at Uppsala and Umeå Universities have found that general cognitive ability (intelligence) has a bearing, in the first year and two years after the heart attack, on how well men take statins prescribed for them.
Patients who have had heart attacks almost always get prescriptions for statins, which are among the key drugs for secondary prevention and effectively reduce cholesterol levels. Not taking one's statins raises the risk of suffering from a new heart attack or premature death. Nonetheless, some patients choose not to continue taking them. The risk of discontinuing statins is associated with various factors, such as side-effects, degree of morbidity and socioeconomic status.
The study in question included more than 20 variables, such as age, diabetes, employment status, medications at discharge, and self-assessed physical and mental health. The cognitive ability of more than 2,500 patients had been measured roughly 30 years before the heart attack, when their compulsory military service began, and the researchers found an association between low general cognitive ability and an elevated risk of not taking the statins prescribed.
'It's very important for the patients themselves to take personal responsibility for their health after the heart attack -- taking their medication, eating a healthy diet, taking exercise and not smoking. This study inspires hope that we might be able to improve tailor-made care, based on the patients' cognitive capacity,' says John Wallert, a clinical psychologist and PhD student at Uppsala University.
Jointly with epidemiologist Claudia Lissåker, cardiologist Claes Held, psychologist Erik Olsson and Professor Guy Madison, Wallert used data from men aged 60 or younger whose first heart attack occurred between 2006 and 2011, as registered in the SWEDEHEART national quality register. Data was linked with the Swedish National Archives' register for military conscription, INSARK, containing data on cognitive ability from male conscript testing in 1965-1997. The Swedish Pharmaceuticals Registry and self-reported medication then provided information about the patients' statin intake.
'Data in this study are limited to relatively young men and follow-up studies should also include older people and women,' Wallert says.
'Current treatment and aftercare guidelines for heart attacks don't pinpoint the significance of cognitive ability, which is vital for planning, memory and executive function in everyday life. Previous studies have shown that cognitive ability is extremely stable between the ages of 18 and 65 in its systematic variation from one individual to another. What we have here is a previously unknown long-term predictor that seems to contribute to whether these patients take their statins or not. We hope this may be useful in healthcare and communication with patients,' Wallert says.
'Several studies have shown that cognitive ability predicts a range of established lifestyle risk factors, such as smoking, physical inactivity, diabetes, and now also non-compliance with taking statins after a heart attack. With tailor-made care, aggregate research suggests that we should take patients' cognitive ability into account as well. Today, secondary prevention after heart attack has a clear structure, based on repeat visits to the cardiologist and cardiac nurse, which are a vital requirement for tailor-made care. There may possibly be a risk of some patients with lower cognitive ability falling through the cracks of present-day care at the stage when patients need to make key behavioural changes that, in turn, affect their risk of having another heart attack and dying prematurely.'
Older adults with higher levels of physical activity have pain modulation patterns that might help lower their risk of developing chronic pain, reports a study in PAIN®, the official publication of the International Association for the Study of Pain (IASP). The journal is published by Wolters Kluwer.
In tests of pain processing by the central nervous system, physically active older adults have lower pain perception and are better able to block responses to painful stimuli, according to the new research by Kelly M. Naugle, PhD, and colleagues of Indiana University-Purdue University Indianapolis. "This study provides the first objective evidence suggesting that physical activity behavior is related to the functioning of the endogenous pain modulatory systems in older adults," the researchers write.
Being More Active, Less Sedentary, Affects Pain Perceptions in Older Adults
Dr. Naugle and colleagues performed a series of experiments in 51 healthy adults, aged 60 to 77. All wore an activity monitor device for one week to measure their level of physical activity. They then underwent two tests of pain modulation--functions affecting the way pain is interpreted and perceived by the central nervous system.
One test, called "temporal summation," measured the production (facilitation) of pain responses to repeated pain stimuli. The other test, called "conditioned pain modulation," assessed the reduction (inhibition) of pain responses to competing pain stimuli.
In both tests, pain modulation was significantly related to daily physical activity level. Older adults with more frequent moderate-to-vigorous physical activity had lower pain scores on the temporal summation test--indicating less pain facilitation. Those who did more light physical activity or had less sedentary time per day had lower pain scores on the conditioned pain modulation test--indicating better pain inhibition.
In other words, older adults who did more moderate to vigorous physical activity perceived less facilitation of pain, while those who did at least some activity were better able to block pain perceptions. These differences may be relevant to the "central sensitization" process believed to be responsible for the transition from acute to chronic pain.
Previous studies have shown that pain modulation processes are dysregulated in patients with chronic pain syndromes--for example, arthritis, back pain, and fibromyalgia. People with higher pain facilitation and lower pain inhibition are more likely to develop problems with chronic pain.
The results are consistent with studies in younger adults suggesting that higher levels of physical activity are related to "more efficient conditioned pain modulation." Older adults are more likely to be physically inactive, which might make them more vulnerable to chronic pain.
"Our data suggest that low levels of sedentary behavior and greater light physical activity may be critical in maintaining effective endogenous pain inhibitory function in older adults," Dr. Naugle and coauthors write. Further studies will be needed to test the implications for physical activity programs to reduce and prevent pain in older adults. For example, it might be possible to match the patient's specific dysfunctional pain modulation pattern to the type of physical activity that can best improve their pain response patterns
People living in neighborhoods with more birds, shrubs and trees are less likely to suffer from depression, anxiety and stress
People living in neighbourhoods with more birds, shrubs and trees are less likely to suffer from depression, anxiety and stress, according to research by academics at the University of Exeter, the British Trust for Ornithology and the University of Queensland.
The study, involving hundreds of people, found benefits for mental health of being able to see birds, shrubs and trees around the home, whether people lived in urban or more leafy suburban neighbourhoods.
The study, which surveyed mental health in over 270 people from different ages, incomes and ethnicities, also found that those who spent less time out of doors than usual in the previous week were more likely to report they were anxious or depressed.
After conducting extensive surveys of the number of birds in the morning and afternoon in Milton Keynes, Bedford and Luton, the study found that lower levels of depression, anxiety and stress were associated with the number of birds people could see in the afternoon. The academics studied afternoon bird numbers - which tend to be lower than birds generally seen in the morning - because are more in keeping with the number of birds that people are likely to see in their neighbourhood on a daily basis.
In the study, common types of birds including blackbirds, robins, blue tits and crows were seen. But the study did not find a relationship between the species of birds and mental health, but rather the number of birds they could see from their windows, in the garden or in their neighbourhood.
Previous studies have found that the ability of most people to identify different species is low (e.g. Dallimer et al. 2012), suggesting that for most people it is interacting with birds, not just specific birds, that provides well-being.
University of Exeter research fellow Dr Daniel Cox, who led the study, said: "This study starts to unpick the role that some key components of nature play for our mental well-being".
Birds around the home, and nature in general, show great promise in preventative health care, making cities healthier, happier places to live".
The positive association between birds, shrubs and trees and better mental health applied, even after controlling for variation in neighbourhood deprivation, household income, age and a wide range of other socio-demographic factors.
Following current dietary recommendations may lead to small improvements in overall heart health in overweight individuals, according to a study published today in the Journal of the American College of Cardiology.
The most recent recommendations of the U.S. Dietary Guidelines Advisory committee support three dietary patterns to prevent chronic disease--the healthy American diet, the Mediterranean diet and a vegetarian diet--all of which advise individuals to eat more fruit, vegetables and whole grains, plus more cholesterol lowering "functional" foods such as oats, barley, nuts and plant protein foods such as soy.
Researchers randomized 919 adult participants in Toronto who had a body mass index of more than 25 kg/m2 to receive either one of three treatments or to a control group. Participants who were members of the same family were all assigned the same treatment. All participants received a copy of Health Canada's Food Guide. No further advice was given to the control group.
The first treatment group received additional dietary advice weekly for the first month and monthly for the following five months through 20 to 30 minute telephone interviews. Individuals were advised regarding benefits, strategies for change and barriers to change and were encouraged to increase intake of fruit, vegetables, whole grain cereals and cholesterol lowering functional food, and to reduce the intake of meat and sweets. The second group received a weekly food basket for six months reflecting advice given to the first group but did not receive dietary advice. The third treatment group received the weekly food basket and dietary advice.
After six months, only small increases were observed in the intake of fruits, vegetables, whole grains and cholesterol lowering foods across all groups, and the only consistent increases were seen in the group that received both food provisions and advice. At 18 months, small increases remained for the intake of healthy foods, but these increases were significantly reduced from the already modest six month increases.
Small reductions in body weight, waist circumference and blood pressure were observed in the control and treatment groups at six months. Reductions in body weight and weight circumference were maintained at the 18-month follow-up, while blood pressure reduced significantly during this time. Levels of high-density lipoprotein cholesterol rose between six and 18 months.
"These data demonstrate the difficulty in effectively promoting fruit, vegetable and whole grain cereals to the general population using recommendations that, when followed, decrease risk factors for chronic disease," said David J.A. Jenkins, MD, PhD, DSc, professor and Canada Research Chair in Nutrition and Metabolism at the department of nutritional science at the University of Toronto and lead author of the paper. "They indicate an urgent need for innovative approaches to support the implementation of current dietary advice."
According to the researchers, the success of dietary advice may be influenced by the perception of immediate benefit from the intervention. Greater emphasis is required on the long-term health benefits of sustaining a healthy diet for otherwise healthy people. Individuals are also prone to habits that are resistant to change, making it important to develop supportive food environments and to emphasize overcoming barriers related to methods of food preparation and to illustrate situations in which desired foods can be eaten, such as meals and snacks.
Researchers analyzed nutrition studies in a new review published today in the Journal of the American College of Cardiology, which intends to cut through the confusion about the best dietary patterns to reduce heart disease. The review concludes current evidence strongly supports eating plenty of fruits, vegetables, whole grains, legumes, and nuts in moderation. Although more controversial, some heart-healthy diets may also include very limited quantities of lean meat, fish, low-fat and nonfat dairy products, and liquid vegetable oils.
"There is a great amount of misinformation about nutrition fads, including antioxidant pills, juicing and gluten-free diets," said Andrew Freeman, MD, director of cardiovascular prevention and wellness in the division of cardiology at National Jewish Health in Denver and the paper's lead author. "However, there are a number of dietary patterns that have clearly been demonstrated to reduce the risk of many chronic diseases, including coronary heart disease."
The review examined several of these dietary patterns as well as "hypes and controversies" surrounding nutrition to provide clinicians with information to aid in discussions with patients about dietary habits.
"There is a growing consensus that a predominantly plant-based diet that emphasizes green, leafy vegetables, whole grains, legumes and fruit is where the best improvements are seen in heart health," Freeman said.
Other nutrition topics covered in the review include:
- Eggs and cholesterol. Although a government report issued in 2015 dropped specific recommendations about upper limits for cholesterol consumption, the review concludes, "it remains prudent to advise patients to significantly limit intake of dietary cholesterol in the form of eggs or any high cholesterol foods to as little as possible."
- Vegetable oils. Coconut oil and palm oil should be discouraged due to limited data supporting routine use. The most heart-healthy oil is olive oil, though perhaps in moderation as it is still higher calorie, research suggests.
- Berries and antioxidant supplementation. Fruits and vegetables are the healthiest and most beneficial source of antioxidants to reduce heart disease risk. There is no compelling evidence adding high-dose antioxidant dietary supplements benefits heart health.
- Nuts. Nuts can be part of a heart-healthy diet. But beware of consuming too many, because nuts are high in calories.
- Juicing. While the fruits and vegetables contained in juices are heart-healthy, the process of juicing concentrates calories, which makes it is much easier to ingest too many. Eating whole fruits and vegetables is preferred, with juicing primarily reserved for situations when daily intake of vegetables and fruits is inadequate. If you do juice, avoid adding extra sugar by putting in honey, to minimize calories.
- Gluten. People who have celiac disease or other gluten sensitivity must avoid gluten--wheat, barley and rye. For patients who don't have any gluten sensitivities, many of the claims for health benefits of a gluten-free diet are unsubstantiated, the researchers conclude.
"In addition, it's very hard to separate the effects of specific nutrients in a food. For example, an apple contains many components including proteins, vitamins and fiber," he said.
Many people who eat a healthy diet also have other healthy lifestyle behaviors, such as regular physical activity, getting enough sleep, and not smoking, and it can be hard to pinpoint the diet's effect separate from these other behaviors.
"And some nutrition studies tend to be based on surveys that rely on people's memories of what they ate, which isn't always reliable," Freeman said.
"The founder of modern medicine, Hippocrates, said, 'Let food be thy medicine,'" Freeman said. "But the vast majority of doctors have little nutrition training. If we can get doctors, and especially cardiologists, to understand the value of nutrition in medical practice, we can have a greater impact on reducing heart disease, and it is certainly cost-effective."
Lack of exercise and excessive weight are strongly associated with a type of heart failure that has a particularly poor prognosis, UT Southwestern Medical Center researchers determined in an analysis of data from three large studies.
Heart failure is a chronic condition in which the heart is unable to supply enough oxygenated blood to meet the demands of the body. Heart failure is approximately equally divided between two subtypes: heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). Ejection fraction refers to the percentage of the blood that exits the heart with each contraction.
"Previous studies have consistently found an association between low levels of physical activity, high BMI, and overall risk of heart failure, but this study shows that the association is more pronounced for heart failure with preserved ejection fraction, the type of heart failure that is the most challenging to treat," said preventive cardiologist Dr. Jarett Berry, Associate Professor of Internal Medicine at UT Southwestern, and the study's senior author.
The study appears in the Journal of the American College of Cardiology.
In heart failure with preserved ejection fraction, the heart stiffens. Instead of being soft, it's rigid and it resists expansion. Cardiologists often explain the difference between the two types of heart failure by saying that in heart failure with preserved ejection fraction, the heart doesn't relax enough, while in heart failure with reduced ejection fraction the heart doesn't squeeze enough. Many treatments have been developed for treating the latter but there are no evidence-based treatments for the former.
"The five-year survival rate among heart failure with preserved ejection fraction patients is around 30 to 40 percent. While heart failure with reduced ejection fraction survival has improved significantly over the years, heart failure with preserved ejection fraction prognosis is little changed," said Dr. Ambarish Pandey, a cardiology fellow in Internal Medicine at UT Southwestern Medical Center and first author of the study.
The pooled analysis looked at data from 51,000 participants in three cohort studies, the Women's Health Initiative, the Multiethnic Study of Atherosclerosis (MESA), and the Cardiovascular Health Study. Among the 51,000 participants, there were 3,180 individuals who developed heart failure. Of these, 39 percent were heart failure with preserved ejection fraction, 29 percent were heart failure with reduced ejection fraction, and 32 percent had not been classified when the data was gathered.
The incidence of heart failure with preserved ejection fraction was 19 percent lower for individuals who exercised at recommended levels. Similarly, body mass index (BMI) had an inverse relationship with heart failure with preserved ejection fraction. Higher BMI levels were more strongly associated with heart failure with preserved ejection fraction than with heart failure with reduced ejection fraction.
Heart failure with preserved ejection fraction is a growing problem as the population ages, and is particularly a problem among elderly women.
Medications such as ACE inhibitors, beta blockers, and aldosterone antagonists have been shown in large-scale randomized trials to reduce mortality in patients with heart failure with reduced ejection fraction. Clinical trials have not identified medications that reduce mortality in patients with heart failure with preserved ejection fraction. Heart transplant is the ultimate option for some patients with heart failure with reduced ejection fraction but is not an option for patients with heart failure with preserved ejection fraction, all of which means that prevention is crucial for heart failure with preserved ejection fraction.
"These findings highlight the importance of lifestyle interventions such as increasing physical activity levels and reducing weight to combat the growing burden of this disease," said Dr. Berry, Dedman Family Scholar in Clinical Care.
Thursday, February 23, 2017
In a large multiethnic study, being underweight was linked with an increased risk of early death among postmenopausal women. Also, a higher waist circumference--but not being overweight or slightly obese--was associated with premature mortality, indicating that abdominal fat is more deadly than carrying excess weight.
Interestingly, Hispanic women in the study had a lower mortality rate at any given body mass index or waist circumference compared with non-Hispanic whites or African-Americans.
"We have used data from the large prospective cohort of the US Women's Health Initiative to add evidence on the relationship of general and central obesity with all-cause mortality in older women, especially in African American and Hispanic American older women, who have not been well represented in previous research on this topic," said Dr. Zhao Chen, lead author of the Journal of the American Geriatrics Society study. "Our study findings have called public health attention to reduce central obesity in older women from different racial/ethnic groups and to reconsider recommendations on the range of healthy body mass index in older women."
A study from the Research Institute of the McGill University Health Centre (RI-MUHC) shows that physician-delivered step count prescriptions, combined with the use of a pedometer, can lead to a 20 per cent increase in daily steps, as well as measurable health benefits, such as lower blood sugar and lower insulin resistance, for patients with hypertension and/or type 2 diabetes.
Scientific research clearly indicates that at least 30 minutes of daily exercise can reduce the risk of cardiovascular disease, some types of cancer and high blood pressure. Regular walking can lead to a 40 per cent reduction in both mortality and vascular event rates over the next decade for adults with type 2 diabetes. Despite this evidence, the current low level of physical activity among Canadians remains a dominant public health concern.
"As physicians, we have to face reality and admit that for many patients, just telling them to be more physically active simply doesn't work," says Dr. Kaberi Dasgupta, a physician researcher at the RI-MUHC and principal author of the study. "A lot of people want to be active, but it is very difficult to change health behaviors. The idea in this study is to use step counts almost as a medication."
Dr. Dasgupta's work focuses on the prevention and the management of blood vessel disease in people with diabetes or who are at risk for diabetes. She has been interested in the impact of step counting on people's health for many years. "Our physical activity is often divided throughout our day, so measuring distance can be complicated. With step-counting, it is easier to quantify your daily physical activity, especially for people who do not run or go to the gym."
This study involved 364 patients and 74 doctors from different Montreal hospitals. Co-leading the trial with Dr Dasgupta were Drs Stella Daskalopoulou and Ellen Rosenberg. All patients continued their normal medical routine with their physicians but some patients also had written step count prescriptions and were given a pedometer to monitor their activity. After one year, patients who were prescribed steps walked 1,200 steps more per day on average than patients who were not. Those with type 2 diabetes lowered their blood sugar levels and there were also improvements in insulin resistance. The study, which was published in the journal Diabetes, Obesity, and Metabolism, is the first to show that a written step prescription can be beneficial to patient health.
Dr. Dasgupta's team aims to take this study -- and patients -- a step further. "If we want doctors to prescribe physical activities, it needs to be aligned and integrated in the medical routine and added to health guidelines, which we plan on doing in the near future."
It is recommended that people walk at least 10,000 steps daily to experience health benefits. People walking under 5,000 steps have high risk of developing hypertension and type 2 diabetes - conditions that can ultimately lead to heart attacks, strokes and blindness.
For the first time a "tipping point" molecular link between the blood sugar glucose and Alzheimer's disease has been established by scientists, who have shown that excess glucose damages a vital enzyme involved with inflammation response to the early stages of Alzheimer's.
Abnormally high blood sugar levels, or hyperglycaemia, is well-known as a characteristic of diabetes and obesity, but its link to Alzheimer's disease is less familiar.
Diabetes patients have an increased risk of developing Alzheimer's disease compared to healthy individuals. In Alzheimer's disease abnormal proteins aggregate to form plaques and tangles in the brain which progressively damage the brain and lead to severe cognitive decline.
Scientists already knew that glucose and its break-down products can damage proteins in cells via a reaction called glycation but the specific molecular link between glucose and Alzheimer's was not understood.
But now scientists from the University of Bath Departments of Biology and Biochemistry, Chemistry and Pharmacy and Pharmacology, working with colleagues at the Wolfson Centre for Age Related Diseases, King's College London, have unraveled that link.
By studying brain samples from people with and without Alzheimer's using a sensitive technique to detect glycation, the team discovered that in the early stages of Alzheimer's glycation damages an enzyme called MIF (macrophage migration inhibitory factor) which plays a role in immune response and insulin regulation.
MIF is involved in the response of brain cells called glia to the build-up of abnormal proteins in the brain during Alzheimer's disease, and the researchers believe that inhibition and reduction of MIF activity caused by glycation could be the 'tipping point' in disease progression. It appears that as Alzheimer's progresses, glycation of these enzymes increases.
The study is published in the journal Scientific Reports.
Professor Jean van den Elsen, from the University of Bath Department of Biology and Biochemistry, said: "We've shown that this enzyme is already modified by glucose in the brains of individuals at the early stages of Alzheimer's disease. We are now investigating if we can detect similar changes in blood.
"Normally MIF would be part of the immune response to the build-up of abnormal proteins in the brain, and we think that because sugar damage reduces some MIF functions and completely inhibits others that this could be a tipping point that allows Alzheimer's to develop.
Dr Rob Williams, also from the Department of Biology and Biochemistry, added: "Knowing this will be vital to developing a chronology of how Alzheimer's progresses and we hope will help us identify those at risk of Alzheimer's and lead to new treatments or ways to prevent the disease.
Dr Omar Kassaar, from the University of Bath, added: "Excess sugar is well known to be bad for us when it comes to diabetes and obesity, but this potential link with Alzheimer's disease is yet another reason that we should be controlling our sugar intake in our diets."
Globally there are around 50 million people with Alzheimer's disease, and this figure is predicted to rise to more than 125 million by 2050. The global social cost of the disease runs into the hundreds of billions of dollars as alongside medical care patients require social care because of the cognitive effects of the disease.
The study was funded by the Dunhill Medical Trust. Human brain tissue for this study was provided through Brains for Dementia Research, a joint initiative between Alzheimer's Society and Alzheimer's Research UK in association with the Medical Research Council.
You've heard it a thousand times, that little catchphrase with the magic number encouraging you to eat "five a day" of fruits and vegetables for better health. But it turns out that the real magic number is eight, according to a new comprehensive study just published in the International Journal of Epidemiology.
The study, spearheaded by Dagfinn Aune, from the Norwegian University of Science and Technology (NTNU) and Imperial College London, shows that 7.8 million deaths worldwide could be prevented each year if people ate more fruits and vegetables. Aune says the more you eat, the lower the overall risk of heart disease, stroke, cancer and premature death.
"The results support recommendations to increase the amount of fruits and vegetables people eat," said Aune.
The study shows that the risk of dying prematurely from all causes was reduced by almost a third, and the risk of cardiovascular disease by about a quarter in people who ate 800 grams of fruit and vegetables every day, compared with those who ate very little or no fruits and vegetables.
"We see a gradual reduction in risk with increasing consumption, so a low or moderate intake is better than not eating fruits and vegetables at all," he said.
Eight a day
It should be no surprise to anyone that eating fruits and vegetables is linked to better health, but none of the previous analyses that have established this link have examined how much you should eat to increase health benefits.
The meta-analysis undertaken by Aune and his colleagues is by far the largest on this topic to date. The researchers looked at a total of 142 publications from 95 different population studies that studied the relationship between consumption of fruits and vegetables and the subsequent risk of chronic diseases. Each analysis included information on several hundred thousand people.
"The risk of heart disease, strokes and premature death decreased by 10.8 per cent for each 200 gram increase in consumption of fruit or vegetables--up to an intake of 800 grams," Aune said.
He stressed that the greatest impact from increasing a person's daily intake of fruit and vegetables appears to be in people do not eat fruit and vegetables at all, or who eat very little of them. But there were also benefits from additional increases in fruit and vegetable consumption for people whose diets already include some fruit and vegetables.
Many national health authorities recommend that people eat at least "five a day," which corresponds to approximately 500 grams of fruit and vegetables. In other words, the new analysis suggests that the risk of disease and premature death can be reduced even more by eating more fruits and vegetables than recommended.
Do fruit and vegetables really have a protective effect?
People who eat lots of fruits and vegetables are more likely to be healthy in other ways.
For example, they are generally more physically active, smoke less, and are more likely to avoid large amounts of alcohol and red or processed meat compared to people who eat less fruit and vegetables.
Perhaps that means there are factors other than fruit and vegetables that are behind the reduced risk of cardiovascular disease, cancer and premature death that the researchers found?
"Many, but not all of the studies in our analysis adjusted for these factors. We saw pretty much no significant difference in the results of studies with and without this kind of adjustment. Nevertheless, we cannot completely exclude that the results are due to factors we have not been able to take into account," says Aune.
Reductions in premature deaths
The researchers also calculated how many premature deaths that could be prevented each year worldwide if everyone ate 800 grams of fruit and vegetables every day. The figure they arrived at was 7.8 million deaths each year. If everyone ate 500 grams of fruits and vegetables a day, that figure would be 5.4 million deaths.
Two to four million deaths related to cardiovascular disease could be prevented a year if everyone ate the optimal amount of fruits and vegetables, the researchers said, while for cancer that number was approximately 660,000 deaths.
"Part of what is most fascinating about this study is that the association between fruit and vegetables and mortality is greater than one would expect only on the basis of the relationships we find with cardiovascular disease and cancer, so it is conceivable that fruit and vegetables are beneficial in preventing other diseases and causes of death as well," Aune said. "But since we had very limited data, we could not do analyses for other causes of death. This is something we want to pursue."
Which fruits and vegetables protect most, and why?
The meta-analysis is also the first to examine subcategories and individual varieties of fruits and vegetables that can be connected to a reduced risk of various diseases and premature death.
Apples and pears, citrus fruit, fruit juice, green leafy vegetables and fruits and vegetables rich in vitamin C were among the types of fruit and vegetables that were linked to a reduced risk of cardiovascular disease and premature death.
Canned fruits, however, were linked to increased risk of cardiovascular disease and premature death.
"However, we need more studies on specific types of fruit and vegetables because relatively few of the studies in our analysis had looked at this issue," said Aune.
Fruits and vegetables contain fiber, vitamin C, antioxidants, potassium and flavonoids, all of which have been directly linked to good health. A high intake of fiber can help lower cholesterol, blood pressure and inflammation in the body, improve blood vessel function and prevent people from becoming overweight and obese.
Antioxidants can prevent free radicals and other reactive oxygen species from damaging the body's genetic material. Fruits and vegetables can also have a positive effect on bacteria in the intestines.
"Supplementing with antioxidants and vitamins does not have the same beneficial effects, so probably it's the whole package of beneficial substances that you get from eating fruits and vegetables that acts synergistically," said Aune, who was recently awarded his doctorate from NTNU. He is now an associate professor at Bjørknes University College in Oslo.
Wednesday, February 22, 2017
Weekly Tai Chi exercise sessions may reduce stroke risk by lowering high blood pressure and increasing the good cholesterol, or high-density lipoprotein (HDL), according to research presented at the American Stroke Association's International Stroke Conference 2017.
Researchers studied how Tai Chi compared to brisk walking for reducing stroke risk in 246 adults with known stroke risk factors, including high blood pressure. Participants were randomly assigned to a group that participated in two 60-minute Tai Chi sessions each week; a walking group that walked briskly for 30 minutes every day; or a control group, which was told to maintain the activities they were doing before the study.
At three months into the assigned activities, researchers found:
The Tai Chi group had notably greater reductions of 10.25 mm Hg in systolic (upper number) and 6.5 mm Hg in diastolic (lower number) blood pressure measurements than those in the control group.
The Tai Chi group also had an average 0.16 millimole (mmol/L) increase in HDL, compared to the control group.
There were no notable differences in blood pressure or HDL in the walking group.
None of the groups experienced notable changes in total cholesterol, blood sugar levels, body mass index, waist circumference or body fat percentage.
A study longer than three months is needed to monitor the effects of continuing Tai Chi and brisk walking for stroke prevention, researchers suggested.
People who have heart disease risks in middle age - such as diabetes, high blood pressure or smoking - are at higher risk for dementia later in life, according to research presented at the American Stroke Association's International Stroke Conference 2017.
"The health of your vascular system in midlife is really important to the health of your brain when you are older," said Rebecca F. Gottesman, M.D., Ph.D., lead researcher and associate professor of neurology and epidemiology at the Johns Hopkins University in Baltimore.
In an ongoing study that began in 1987 and enrolled 15,744 people in four U.S. communities, the risk of dementia increased as people got older. That was no surprise, but heart disease risks detected at the start of the study, when participants were between 45-64 years of age, also had a significant impact on later dementia, researchers noted. Dementia developed in 1,516 people during the study, and the researchers found that the risk of dementia later in life was:
- 41 percent higher in midlife smokers than in non-smokers or former smokers;
- 39 percent higher in people with high blood pressure (?140/90 mmHg) in middle age, and 31 percent higher in those with pre-hypertension (between 120/80 mmHg and 139/89 mmHg) compared to those with normal blood pressure; and
- 77 percent higher in people with diabetes in middle age than in non-diabetics.
Diabetes raises the risk almost as much as the most important known genetic risk factor for Alzheimer's disease," Gottesman said.
Overall, the risk of dementia was 11 percent lower in women. The risk was highest in individuals who were black, had less than a high school education, were older, carried the gene known to increase Alzheimer's risk, or had high blood pressure, diabetes or were current smokers at the time of initial evaluation.
Smoking and carrying the gene known to increase the chance of Alzheimer's were stronger risk factors in whites than in blacks, the researchers noted.
"If you knew you carried the gene increasing Alzheimer's risk, you would know you were predisposed to dementia, but people don't necessarily think of heart disease risks in the same way. If you want to protect your brain as you get older, stop smoking, watch your weight, and go to the doctor so diabetes and high blood pressure can be detected and treated," said Gottesman.
Because Atherosclerosis Risk in Communities is an observational study, the current study could not test whether treating heart risk factors will result in a lessened dementia risk later in life.
"The benefit is that this is a long-term study and we know a lot about these people. Data like these may supplement data from clinical trials that look at the impact of treatment for heart disease risks," Gottesman said.
Data from the Framingham Heart Study has shown that people who consistently sleep more than nine hours each night had double the risk of developing dementia in 10 years as compared to participants who slept for 9 hours or less. The findings, which appear in the journal Neurology, also found those who slept longer had smaller brain volumes.
It is believed that the number of Americans with Alzheimer's disease and other dementias will grow each year as the size and proportion of the U.S. population age 65 and older continues to increase. By 2025 the number of people age 65 and older with Alzheimer's disease is estimated to reach 7.1 million.
A large group of adults enrolled in the Framingham Heart Study (FHS), were asked to indicate how long they typically slept each night. Participants were then observed for 10 years to determine who developed dementia, including dementia due to Alzheimer's disease. Researchers from Boston University School of Medicine (BUSM) then analyzed the sleep duration data and examined the risk of developing dementia.
"Participants without a high school degree who sleep for more than 9 hours each night had six times the risk of developing dementia in 10 years as compared to participants who slept for less. These results suggest that being highly educated may protect against dementia in the presence of long sleep duration," explained co-corresponding author Sudha Seshadri, MD, professor of neurology at BUSM and FHS senior investigator.
According to the researchers the results suggest that excessive sleep may be a symptom rather than a cause of the brain changes that occur with dementia. Therefore, interventions to restrict sleep duration are unlikely to reduce the risk of dementia.
"Self-reported sleep duration may be a useful clinical tool to help predict persons at risk of progressing to clinical dementia within 10 years. Persons reporting long sleep time may warrant assessment and monitoring for problems with thinking and memory," added co-corresponding author Matthew Pase, PhD, fellow in the department of neurology at BUSM and investigator at the FHS.
The researchers believe screening for sleeping problems may aid in the early detection of cognitive impairment and dementia. The early diagnosis of dementia has many important benefits, such as providing a patient the opportunity to more activity direct their future plans and health care decisions.
Taking popular heartburn drugs for prolonged periods has been linked to serious kidney problems, including kidney failure. The sudden onset of kidney problems often serves as a red flag for doctors to discontinue their patients' use of so-called proton pump inhibitors (PPIs), which are sold under the brand names Prevacid, Prilosec, Nexium and Protonix, among others.
But a new study evaluating the use of PPIs in 125,000 patients indicates that more than half of patients who develop chronic kidney damage while taking the drugs don't experience acute kidney problems beforehand, meaning patients may not be aware of a decline in kidney function, according to researchers at Washington University School of Medicine in St. Louis and the Veterans Affairs St. Louis Health Care System. Therefore, people who take PPIs, and their doctors, should be more vigilant in monitoring use of these medications.
The study is published Feb. 22 in Kidney International.
The onset of acute kidney problems is not a reliable warning sign for clinicians to detect a decline in kidney function among patients taking proton pump inhibitors, said Ziyad Al-Aly, MD, the study's senior author and an assistant professor of medicine at Washington University School of Medicine. "Our results indicate kidney problems can develop silently and gradually over time, eroding kidney function and leading to long-term kidney damage or even renal failure. Patients should be cautioned to tell their doctors if they're taking PPIs and only use the drugs when necessary."
More than 15 million Americans suffering from heartburn, ulcers and acid reflux have prescriptions for PPIs, which bring relief by reducing gastric acid. Many millions more purchase the drugs over-the-counter and take them without being under a doctor's care.
The researchers -- including first author Yan Xie, a biostatistician at the St. Louis VA -- analyzed data from the Department of Veterans Affairs databases on 125,596 new users of PPIs and 18,436 new users of other heartburn drugs referred to as H2 blockers. The latter are much less likely to cause kidney problems but often aren't as effective.
Over five years of follow up, the researchers found that more than 80 percent of PPI users did not develop acute kidney problems, which often are reversible and are characterized by too little urine leaving the body, fatigue and swelling in the legs and ankles.
However, more than half of the cases of chronic kidney damage and end-stage renal disease associated with PPI use occurred in people without acute kidney problems.
In contrast, among new users of H2 blockers, 7.67 percent developed chronic kidney disease in the absence of acute kidney problems, and 1.27 percent developed end-stage renal disease.
End-stage renal disease occurs when the kidneys can no longer effectively remove waste from the body. In such cases, dialysis or a kidney transplant is needed to keep patients alive.
"Doctors must pay careful attention to kidney function in their patients who use PPIs, even when there are no signs of problems," cautioned Al-Aly, who also is the VA's associate chief of staff for research and education and co-director of the VA's Clinical Epidemiology Center. "In general, we always advise clinicians to evaluate whether PPI use is medically necessary in the first place because the drugs carry significant risks, including a deterioration of kidney function."
An innovative psychological treatment can help older people who are suffering from lower-severity depression, say researchers at the University of York. It can also prevent more severe depression from developing.
Depression is common amongst older people, with one in seven meeting the criteria for full-blown depression. Older people at the greatest risk of depression are those who suffer from loneliness and long-term illnesses, both of which affect this age group disproportionately.
Being depressed can also make health problems worse and older people with depression are at an increased risk of dying. The CASPER clinical trial focussed on older people with lower-severity symptoms who are at the highest risk of becoming clinically depressed.
CASPER is the largest-ever study of its kind and is reported in the Journal of the American Medical Association (JAMA). York based researchers showed that a simple and low-cost intervention reduced the symptoms of depression in older people (aged 65 and over).
Those who received the intervention were also less likely to be more severely depressed after a year. Older people were also less anxious and had improved quality of life compared to people who just received care from their GP.
"We developed our Collaborative Care intervention after consulting with older people and considering evidence about effective treatments for depression." said study manager, Kate Bosanquet, from the University of York's Department of Health Sciences.
"We used a simple psychological approach known as behavioural activation. Older people were encouraged to re-engage with social activity and to find alternative ways of being mentally or physically active. This is important since people with depression commonly withdraw from these types of activities and this makes things worse."
"Older people found Collaborative Care to be an acceptable way of accessing help,' said Della Bailey, one of the therapists working on the study.
"We mostly worked with people over the telephone and found that participants appreciated this approach. This also meant that older people did not have to travel to hospital to receive psychological care."
The study team, which also included researchers from the NHS, other universities and the Hull York Medical School are now planning to train NHS therapists in Collaborative Care to ensure that older people all over the UK can benefit from this intervention.
"'This is the largest rigorous study of its kind and we are very grateful to the National Institute for Health Research, which funded our work, and to the hundreds of older people who participated in the study," said Chief Investigator, Professor Simon Gilbody.
Tuesday, February 21, 2017
A product of digesting a micronutrient found in soy may hold the key to why some people seem to derive a heart-protective benefit from eating soy foods, while others do not, a University of Pittsburgh Graduate School of Public Health-led study discovered.
Japanese men who are able to produce equol -- a substance made by some types of "good" gut bacteria when they metabolize isoflavones (micronutrients found in dietary soy)--have lower levels of a risk factor for heart disease than their counterparts who cannot produce it, according to the research published in the British Journal of Nutrition.
"Scientists have known for some time that isoflavones protect against the buildup of plaque in arteries, known as atherosclerosis, in monkeys, and are associated with lower rates of heart disease in people in Asian countries," said senior author Akira Sekikawa, M.D., Ph.D., an associate professor of epidemiology at Pitt Public Health. "We were surprised when a large trial of isoflavones in the U.S. didn't show the beneficial effects among people with atherosclerosis in Western countries. Now, we think we know why."
All monkeys can produce equol, as can 50 to 60 percent of people in Asian countries. However, only 20 to 30 percent of people in Western countries can.
Sekikawa and his colleagues, who include scientists in Japan, recruited 272 Japanese men aged 40 to 49 and performed blood tests to find out if they were producing equol. After adjusting for other heart disease risk factors such as high blood pressure, cholesterol, smoking and obesity, the team found that the equol-producers had 90-percent lower odds of coronary artery calcification, a predictor of heart disease, than the equol non-producers.
The daily intake of dietary isoflavones -- found in traditional soy foods such as tofu, miso and soymilk--is 25 to 50 milligrams in China and Japan, while it is less than 2 milligrams in Western countries. Equol is available as a supplement--bypassing the need for gut bacteria to produce it--though no clinical trials have been performed to determine a safe dosage for heart protective effects, or if it even does provide such protection.
"I do not recommend that people start taking equol to improve their heart health or for any other reason unless advised by their doctor," said Sekikawa. "Much more study is needed."
Sekikawa and his team are pursuing funding for a much larger observational study to expand on their findings and eventually a randomized clinical trial to examine the effect of taking equol on various medical conditions and diseases.
"Our discovery about equol may have applications far beyond heart disease," said Sekikawa. "We know that isoflavones may be associated with protecting against many other medical conditions, including osteoporosis, dementia, menopausal hot flashes, and prostate and breast cancers. Equol may have an even stronger effect on these diseases."
For patients with breast cancer, physical activity and avoiding weight gain are the most important lifestyle choices that can reduce the risk of cancer recurrence and death, according to an evidence-based review published in CMAJ (Canadian Medical Association Journal).
"Of all lifestyle factors, physical activity has the most robust effect on breast cancer outcomes," writes Dr. Ellen Warner, Sunnybrook Health Sciences Centre, Toronto, Ontario, with coauthor Julia Hamer. "Weight gain of more than 10% body weight after a breast cancer diagnosis increases breast cancer mortality and all-cause mortality. However, there are good reasons to discourage even moderate weight gain because of its negative effects on mood and body image," the authors state.
The review of 67 published articles looks at a variety of lifestyle factors, such as exercise, weight, diet, smoking and more, and examines the changes women can make to improve their chances of survival and reduce the risk of cancer recurring. About one-quarter of women diagnosed with early stage disease will eventually die of later metastases.
As the review contains practical recommendations of interest to patients, their families, physicians and other health care professionals, it is open-access and freely available to a global audience.
While evidence is inconclusive on the impact of some lifestyle behaviours, such as specific diets, alcohol consumption and vitamin supplements, the authors have summarized easy-to-follow key findings and unanswered questions in charts.
- Avoid weight gain -- weight gain during or after breast cancer treatment is linked to breast cancer-related death. Women who are overweight or obese at diagnosis also have poorer prognoses.
- Exercise -- patients should engage in at least 30 minutes of moderate exercise a day, five days a week, or 75 minutes of vigorous exercise per week. Two to three sessions of strength training for large muscle groups are also recommended.
- Diet -- no specific type of diet has been shown to reduce the risk of breast cancer recurrence. Evidence indicates that patients do not need to avoid soy, and it may help with weight management if used to replace higher-calorie meat protein.
- Vitamin supplementation -- moderate consumption of vitamin C may be helpful although more evidence is needed. Vitamin D supplements may be taken to maintain adequate levels for bone strength, since chemotherapy and hormonal treatments can reduce bone density.
- Smoking -- stop smoking. While it is unclear if stopping smoking after a breast cancer diagnosis affects recurrence, the risk of death from smoking-related health issues is a strong reason to quit.
- Alcohol intake -- limiting consumption to one or fewer alcoholic drinks per day may help reduce the risk of a second breast cancer.
Physicians can play an important role in helping patients make positive changes.
"Because it is common for patients to reduce their level of physical activity after a breast cancer diagnosis, it is important for health care professionals to promote and encourage exercise in this patient population," the authors write. "Simply receiving advice from an oncologist to exercise more has been shown to increase patients' level of activity."
An important point to emphasize is that the breast cancer patients in the studies showing the benefits of lifestyle changes were also receiving conventional anticancer therapy; lifestyle changes should never be used as a substitute for standard therapy.
The authors caution that these recommendations are not a silver bullet for all women with breast cancer. Some breast cancers have aggressive biology and will recur despite the most meticulous lifestyle behaviours.
"Patients should not be made to feel that inadequate lifestyle changes have led to recurrence of their cancer," they conclude.
Five new JAMA and JAMA Internal Medicine studies published online compare a variety of health outcomes in men with low testosterone who used testosterone.
Four of the five testosterone-related studies are from the Testosterone Trials, a group of placebo-controlled, coordinated trials designed to determine the efficacy of testosterone gel use by men 65 or older with low testosterone for no apparent reason other than age. The studies examined the health outcomes of memory and cognitive function, bone density, coronary artery plaque volume and anemia.
A fifth study, which was not part of the Testosterone Trials, examined the association of testosterone replacement therapy with cardiovascular outcomes.
In this study, researchers tested if treating older men with low testosterone with a testosterone gel for a year would slow the progression of coronary artery plaque volume compared with a placebo gel. The study included 138 men (73 who received testosterone gel and 65 who received placebo gel).
Findings: Among the men, using testosterone gel for one year compared with placebo gel increased the amount of coronary artery noncalcified plaque, an early sign of increased risk of heart problems. Larger studies are needed to understand the clinical implications of this finding.
Researchers also wanted to know if older men with low testosterone who used testosterone gel for one year compared with placebo gel improved their memory and cognitive function. Among 493 men with age-associated memory impairment (AAMI), 247 received testosterone gel and 246 received placebo for one year.
Findings: Using testosterone gel for one year compared with placebo gel was not associated with improved memory or cognitive function.
JAMA Internal Medicine
In this study, researchers wanted to determine if older men with low testosterone and mild anemia could improve their anemia by using testosterone gel for one year. Of the 788 men enrolled in the Testosterone Trials, 126 were anemic at the start and, of those, 62 had anemia of known causes.
Findings: Testosterone gel increased hemoglobin levels and corrected the anemia (of both known and unknown causes) in older men with low testosterone more than placebo gel.
JAMA Internal Medicine
Another question researchers examined was whether using testosterone gel would help older men with low testosterone improve their bone density and strength. This study included 211 men, of whom 110 received testosterone gel and 101 got the placebo gel.
Findings: Using testosterone gel for one year by older men with low testosterone increased bone density and strength compared with placebo, more so in the spine than hip and more so in trabecular bone than cortical-rich peripheral bone.
JAMA Internal Medicine
This study, which was not part of the Testosterone Trials, examined the association between testosterone replacement therapy (TRT) and cardiovascular outcomes in men 40 or older with low testosterone at Kaiser Permanente California. The study, which was observational, included 8,808 men who were ever prescribed TRT given by injection, orally or topically.
Findings: Among men with low testosterone, dispensed testosterone prescriptions were associated with a lower risk of cardiovascular outcomes over a median follow-up of about three years.
A study published in the Journal of Clinical Lipidology found that higher levels of EPA and DHA omega-3 polyunsaturated fatty acids (PUFA) in red blood cells were associated with a lower risk of all-cause mortality in postmenopausal women. The study specifically examined associations with the omega-3 index, a measure of EPA and DHA levels in red blood cells. Over a 15-year period, the research found that women ages 65 to 80 with omega-3 blood levels in the highest quartile were 20 percent less likely to die from any cause than those in the lowest quartile.
The study analyzed data from more than 6,500 women aged 65-80 who participated in the Women's Health Initiative Memory Study, which began in 1996. The women's PUFA levels were measured in 1996 and then the health outcomes were tracked through August 2014, with the primary outcome being all-cause mortality. After a median of 14.9 years of follow-up, 28.5 percent of the women had passed away. The analysis was adjusted for a wide variety of lifestyle and other factors such as smoking, physical activity and history of cardiovascular disease. This was a prospective cohort study, or a study that follows a group of similar people (a cohort) over time to observe correlations between various factors and health outcomes.
"This is the largest -but far from the only - study to confirm that blood levels of EPA and DHA omega-3 fatty acids, in this case the omega-3 index, are independent predictors of risk for death," said Dr. William Harris, lead author of the study and founder of OmegaQuant Analytics (where the samples were analyzed). "These findings support the view that higher EPA and DHA omega-3 levels are associated with better overall health."
Although this study was observational and did not analyze the effect of a specific intervention, the authors estimated that intakes of approximately 1g of EPA and DHA per day were required to increase omega-3 status from the lowest quartile observed in this study (3.6 percent) to the highest quartile (7.1percent). This approximately equals two and a half to three salmon fillets per week according to the USDA Nutrient Database, or the amount that could be obtained from 1-3 softgels or one teaspoon of a liquid omega-3 supplement daily.
"This study adds to a larger body of evidence demonstrating the positive correlation between higher omega-3 index levels and general wellness," said Adam Ismail, Executive Director of the Global Organization for EPA and DHA Omega-3s (GOED). "The results gathered over a 15-year period support the notion that adequate omega-3 intake is an important part of a healthy lifestyle, just like exercise and following a well-balanced diet."
To put the results of this study in context, a recent paper by Murphy et al found that the omega-3 status of more than 80 percent of Americans was below the omega-3 index observed in the highest quartile in this study. Another paper by Stark et al found that very low omega-3 levels "were observed in North America, Central and South America, Europe, the Middle East, Southeast Asia, and Africa." Thirteen prior studies have also been conducted in this area, twelve of which have found statistically significant reductions in mortality risk associated with the highest levels of omega-3s. These studies can be found in the supplementary data of the Harris paper, with the addition of two studies by Miura et al published last month.
To increase omega-3 intake, it's important to consume specific fish species that contain high levels of EPA and DHA, like salmon, tuna and sardines. Depending on which other foods someone incorporates into his or her diet, a typical person might spend up to $40 per month on these fish to reach this level of omega-3 status. It's also possible to obtain this level of EPA and DHA for about $16 per month with supplement use.
The FDA considers dosages of EPA and DHA up to 3g per day Generally Recognized as Safe (GRAS), a higher level than the 1g per day estimated as a requirement to move from the lowest to highest quartile of omega-3 status in this study. However, consumers should always consult a healthcare provider if they have any concerns or questions before making significant changes to their diet or supplementation habits, and can ask to have their omega-3 levels tested.
Eating a Mediterranean diet could decrease the chances an overweight person will experience regular pain, new research suggests.
A well-established connection between body weight and chronic pain might be explained by inflammation in the body, and the study points to anti-inflammatory foods including fish, nuts and beans as a key to preventing or reducing that pain, said lead researcher Charles Emery, a professor of psychology at The Ohio State University.
"We found that a healthy diet explained the link between weight and pain and specifically that seafood and plant proteins such as peas and nuts and beans were key," said Emery, who is a member of Ohio State's Institute for Behavioral Medicine Research.
"It appears to be telling us that it's not just the quantity of the food you eat that plays a role in pain for heavier individuals, but the quality of food as well."
The researchers developed a model to help them determine whether components of an anti-inflammatory diet high in fruits and vegetables, whole grains and healthy fats, played a role in the likelihood a person's weight would contribute to pain.
And they found a clear pattern. Eating more fish and plant-based proteins such as nuts and beans was linked with less pain, regardless of body weight.
The study also upheld previous research showing that people who are overweight or obese are more likely to experience pain. It included 98 men and women 20 to 78 years old and appears this month in the journal Pain.
"Obesity and pain are significant public health problems. This was an attempt to take a very detailed snapshot of how they might be related," Emery said. "We were interested in the possibility of an inflammatory mechanism explaining the connection because we know there's a high degree of inflammation associated with obesity and with pain."
The mediation model he and his team developed took into account weight, an analysis of self-reported dietary patterns (the Health Eating Index, a measure of diet quality based on U.S. dietary guidelines) and results of a two-question pain survey. Researchers spent three hours with each participant in his or her home.
The researchers accounted for other factors that could influence their results, including age, depression, analgesic medication use and joint pain.
And they tested the model using three different measures of weight - body mass index, waist circumference and body fat percentage. In all three cases, they found evidence that anti-inflammatory proteins may explain the link between increased weight and pain.
"For people with obesity, it's kind of like a cloud hanging over them because they experience high levels of pain and inflammation," Emery said.
The data came from a larger initial study that examined the home environment's role on psychological and social functioning of obese people and people at a healthy weight.
Potential weaknesses of the study include the lack of blood samples that would allow the researchers to look at inflammatory markers and the brevity of the pain measurement. The pain evaluation provides an indicator of pain experienced during the previous month, but does not account for chronic pain of a longer duration.
Emery said his next step is to examine body fat and pain using biomarkers associated with inflammation.
"I'm interested in how our work can contribute to effective treatments for overweight and obese individuals," he said.
A unique study recently published in the authoritative Pediatric Nephrology medical journal shows that excess lipoproteins and fatty acids from high fat diets may be associated with the development of painful and often chronic kidney stones in children.
The breakthrough study, led by DMC's Children's Hospital of Michigan Urology Department Multidisciplinary Pediatric Stone Clinic Medical Director Larisa G. Kovacevic, MD, could have major implications for the diagnosis and treatment of a disorder that currently causes more than half a million emergency room visits in the United States each year. A growing percentage of kidney stone patients today are infants, children and teenagers, according to the latest data from the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.
The newly published prospective controlled trial study (Marked Increase in Urinary Excretion of Apolipoproteins in Children with Nephrolithiasis Associated with Hypercalciuria) found that "abnormalities in lipid [fat] metabolism may play a role in kidney stone formation" -- and also noted that taking steps to identify such fat-metabolism problems in children "may have preventive and therapeutic benefits."
In order to reach that conclusion, the three-year study looked for the presence of a specialized group of "lipid metabolism and transport-related proteins" in 16 children with kidney stones, then compared the results with the levels of similar transport proteins in 14 children who were free of the stones.
The comparison revealed "a significant association between" a high level of lipid metabolism and transport-related proteins and pediatric kidney stones, according to Dr. Kovacevic.
"This is the first study to ever show that there is a marked increase in urinary excretion of these lipid metabolism and transport-related proteins in children with kidney stones," said Dr. Kovacevic, who led the Children's Hospital of Michigan Pediatric Urology Stone Clinic-based research team.
"This finding does suggest -- even though it's preliminary and based on data from only a small number of pediatric subjects -- that what we [pediatric clinicians] may need to do to provide better treatment for kids with kidney stones is to start checking their cholesterol and triglyceride blood levels . . . and if they are elevated, to then treat such patients accordingly by modifying their diets to reduce their intake of fat or providing effective medications, where appropriate."
Dr. Kovacevic said she is grateful for the funding she and her colleagues received from the Children's Hospital of Michigan Foundation, which made the study possible. She added that "these new findings are quite promising and we are excited about the implications for diagnosis and treatment of children with kidney stones."
Dr. Kovacevic also stated that the study was a "collaborative effort" of the Children's Hospital of Michigan Pediatric Stone Clinic and research team and acknowledged the help and support of Dr. Yegappan Lakshmanan, chief of Urology at the Children's Hospital of Michigan, and the major contributions of Dr. Hong Lu, Dr. Joseph A. Caruso and Dr. Ronald Thomas. Additionally, she recognized the continuous support of the entire Children's Hospital of Michigan Urology staff.
"The Children's Hospital of Michigan Pediatric Stone Clinic is unique in Michigan," she said, "because it takes a truly multidisciplinary approach to treating children with this problem. The team includes a nephrologist, a urologist, and a dietitian- which means that we can bring a wide variety of trained specialists to the crucial task of helping children who struggle with this disorder.
"Kidney stones are extremely painful, and they often recur. That means that these children miss school at times, along with other activities, and their parents often go through a great deal of stress and expense in caring for them."
Dr. Kovacevic, who has spent much of the past eight years as a clinical nephrologist specializing in diagnosing and treating kidney stone disorders in the Urology Department at the Children's Hospital of Michigan, said she hopes the just-published study in Pediatric Nephrology will help other researchers to achieve similar breakthroughs.
"As a pediatric kidney specialist who's been attending seminars and giving presentations about this condition all around the world in recent years, I'm greatly encouraged by these new findings," she said. "What we need now is to expand our research into the causes of this disorder and into devising better treatment tools for children with kidney stones.
"Additional new findings in this area could very well lead to new treatment options in which reducing fat intake, along with preventing childhood obesity and overweight, could become important goals in helping to lessen the impact of this often debilitating health condition."
The Children's Hospital of Michigan CEO Luanne Thomas Ewald, while congratulating Dr. Kovacevic and the Pediatric Kidney Stone Clinic on their breakthrough study, said it was "a compelling example of how clinical research can help to improve patient care, day in and day out, by helping to find new treatment modalities and new diagnostic methods.
"Our goal at the Children's Hospital of Michigan is to provide better outcomes for our patients, and this new publication in Pediatric Nephrology seems very likely to help accomplish that."
Physicians and patients like to believe that early detection of cancer extends life, and quality of life. If a cancer is present, you want to know early, right?
Not so fast.
An analysis of cancer screenings by a University of Virginia statistician and a researcher at the National Cancer Institute indicates that early diagnosis of a cancer does not necessarily result in a longer life than without an early diagnosis. And screenings - such as mammograms for breast cancer and prostate-specific antigen tests for prostate cancer - come with built-in risks, such as results mistakenly indicating the presence of cancer (false positives), as well as missed diagnoses (false negatives). Patients may undergo harsh treatments that diminish quality of life while not necessarily extending it.
Yet the benefits of early diagnosis through screening often are touted over the risks.
"It is difficult to estimate the effect of over-diagnosis, but the risk of over-diagnosis is a factor that should be considered," said Karen Kafadar, a UVA statistics professor and co-author of a study being presented Sunday at a session of the 2017 meeting of the American Association for the Advancement of Science. "How many diagnosed cases would never have materialized in a person's lifetime, and gone successfully untreated? Treatments sometimes can cause harm, and can shorten life or reduce quality of life."
Kafadar is not advocating against screening, but her findings show that frequent screening comes with its own risks. As a metric for evaluation, reduction in mortality is considered the standard. So if a disease results in 10 deaths per 100,000 people in a year, and screening reduces the deaths to six per 100,000 people, then there seems to be an impressive 40 percent reduction in mortality.
However, a more meaningful metric, Kafadar said, may be: "How much longer can a person whose case was screen-detected be expected to live, versus a case that was diagnosed only after clinical symptoms appeared?" This issue becomes harder to discern - how long a patient survives after a diagnosis versus how long the patient might have lived anyway. Some cancer cases might never become apparent during a person's lifetime without screening, but with screening might be treated unnecessarily, such as for a possibly non-aggressive cancer. And some aggressive forms of disease may shorten life even when caught early through screening.
Kafadar and her collaborator, National Cancer Institute statistician Philip Prorok, gathered long-term data from several study sources, including health insurance plans and the National Cancer Institute's recently completed long-term randomized control trial on prostate, lung, colorectal and ovarian cancer, to consider several factors affecting the value of screening - over-diagnosis, lead time on a diagnosis and other statistical distortions - to look at not just how many people die, but also life extension.
"People die anyway of various causes," Kafadar said, "but most individuals likely are more interested in, 'How much longer will I live?' Unfortunately, screening tests are not always accurate, but we like to believe they are."
Because the paper considers together the factors that affect statistical understanding of the effectiveness of screening, rather than looking at each of these factors in isolation as previous studies have done, it offers a new statistical methodology for teasing out the relative effects of cancer screening's benefits and risks.
Eating fish and seafood with higher levels of mercury may be linked to a higher risk of amyotrophic lateral sclerosis (ALS), according to a preliminary study released today that will be presented at the American Academy of Neurology's 69th Annual Meeting in Boston, April 22 to 28, 2017. However, fish and seafood consumption as a regular part of the diet was not associated with ALS.
"For most people, eating fish is part of a healthy diet," said study author Elijah Stommel, MD, PhD, of Dartmouth College in Hanover, N.H., and a Fellow of the American Academy of Neurology. "But questions remain about the possible impact of mercury in fish."
While the exact cause of ALS is unknown, some previous studies have suggested mercury to be a risk factor for the disease. In the United States, the primary source of exposure to mercury is through eating fish contaminated with the neurotoxic metal.
Often referred to as Lou Gehrig's disease, ALS is a progressive neurological disease that takes away the ability of nerve cells to interact with the body's muscles. Early symptoms of the disease can include muscle twitching and weakness in a limb. It typically develops into complete paralysis of the body, including the muscles needed to speak, eat and breathe. There is no cure for ALS, and eventually the disease is fatal.
For the study, researchers surveyed 518 people, 294 of whom had ALS, and 224 of whom didn't, on how much fish and seafood they ate. Participants reported the types of fish they ate, and whether they were purchased from stores or caught when they were fishing.
Researchers estimated the annual exposure to mercury by looking up the average mercury levels in the types of fish and the frequency that the participants reported eating them. Swordfish and shark are examples of fish that are considered high in mercury, while salmon and sardines typically have lower levels. Researchers also measured the levels of mercury found in toenail samples from participants with ALS and compared those levels to people without ALS.
The study found that among participants who ate fish and seafood regularly, those in the top 25 percent for estimated annual mercury intake were at double the risk for ALS compared to those with lower levels. A total of 61 percent of people with ALS were in the top 25 percent of estimated mercury intake, compared to 44 percent of people who did not have ALS. They also found that higher mercury levels measured in toenail clippings were associated with an increased risk of ALS. Those in the top 25 percent of mercury levels, based on fish-related intake or toenail clippings, were at a two-fold higher risk of ALS. These findings need to be replicated in additional studies.
The authors emphasize that this study does not negate the fact that eating fish provides many health benefits. However, the study suggests that the public may want to choose species that are known to have a lower mercury content, and avoid consuming fish caught in waters where mercury contamination is well-recognized. More research is needed before fish-consumption guidelines for neurodegenerative illness can be made.
Currently, U.S. Food and Drug Administration (FDA) health recommendations for women of childbearing age and children are to eat two to three weekly meals of species such as salmon or sardines that have low mercury, but are also high in nutrients such as potentially beneficial omega-3 fatty acids. The FDA recommends avoiding fish with the highest mercury levels, such as shark and swordfish. Check for waterbody-specific fish advisories when consuming fish caught by family or friends.
As mindfulness practices rise in popularity and evidence of their worth continues to accumulate, those who work with aging populations are looking to use the techniques to boost cognitive, emotional and physiological health.
But studies so far have shown mixed results in the elderly, and more investigation is needed to determine exactly how best to apply mindfulness in that population, a new review of the research to date has found.
A majority of the 27 studies in the review suggest that the focused attention at the core of mindfulness benefits older people, but others don't point to improvements. And that should prompt more rigorous investigations in search of interventions likely to do the most good, researchers from The Ohio State University found. Their analysis appears in the journal Frontiers in Aging Neuroscience.
"Mindfulness is a practice that really serves as a way to foster a greater quality of life and there's been some thought that it could help with cognitive decline as we age," said Stephanie Fountain-Zaragoza, lead author of the study and a graduate student in psychology.
"Given the growing interest in mindfulness in general, we wanted to determine what we know right now so that researchers can think about where we go from here," she said.
The good news so far: The evidence from a variety of studies points to some benefits for older adults, suggesting that mindfulness training might be integrated into senior centers and group homes, the researchers found.
Older people are an especially important population to study given diminished social support, physical limitations and changes in cognitive health, the researchers point out.
Studies of mindfulness meditation usually involve three types of practices. The first, focused attention, involves sustained attention to a single thing (such as the breath) and an effort to disengage from other distractions.
Open monitoring meditation, often seen as the next step up in mindfulness, includes acknowledging the details of multiple phenomena (sensations, sounds, etc.) without selectively focusing on one of them.
"This includes being open to experiencing thoughts and sensations and emotions and taking them as they come and letting them go," Fountain-Zaragoza said.
Loving-kindness meditation encourages a universal state of love and compassion toward oneself and others.
"The goal with this is to foster compassionate acceptance," said senior author Ruchika Shaurya Prakash, director of Ohio State's clinical neuroscience laboratory and an expert in mindfulness.
In addition to looking at how mindfulness contributed - or did not - to behavioral and cognitive functioning and to psychological wellbeing, some of the research also looked at its potential role in inflammation, which contributes to a variety of diseases.
In all categories of study, including inflammatory processes, Prakash and Fountain-Zaragoza found mixed results.
The hope is that mindfulness could help the elderly preserve attention and capitalize on emotional regulation strategies that naturally improve as we age, Prakash said.
"Around 50 percent of our lives, our minds are wandering and research from Harvard University has shown that the more your mind wanders, the less happy you are," she said.
"Mindfulness allows you to become aware of that chaotic mind-wandering and provides a safe space to just breathe."
In older people, mindfulness ideally has the potential to help with cognition, emotion and inflammation, but little research has been done so far and those studies that have been done have had mixed results and scientific limitations.
While most of the studies in the review showed positive results, the field is limited and would benefit greatly from larger randomized controlled trials, Fountain-Zaragoza said.
"We want to really be able to say that we have strong evidence that mindfulness is driving the changes we see," she said.
Thursday, February 16, 2017
Dr Jonathan Peake and Dr Oliver Neubauer, from QUT's Institute of Health and Biomedical Innovation, led a research review of studies about exercise and immunity.
They found the best way to avoid unfavourable changes in the immune system during a post-workout recovery was consuming carbs during or immediately after the exercise.
The paper was published in the Journal of Applied Physiology.
"There is intense interest in what athletes can do to recover faster from exercise," Dr Peake said.
"Among various nutritional strategies to counteract immune depression during exercise recovery, carbohydrates have proven the most effective. Ingesting carbohydrates during vigorous exercise may help, because carbohydrates maintain blood sugar levels.
"Having stable blood sugar levels reduces the body's stress response, which in turn, moderates any undesirable mobilisation of immune cells. However, more research is warranted to verify that this also helps to prevent infections and illnesses."
Dr Peake said exercise can increase and decrease the number of immune cells in blood.
But he said studies did not support the long-held belief that exercising regularly without allowing sufficient time for the immune system to return to normal increased the risk of a weakened immune system.
"People often have fewer natural killer white blood cells after a workout but we now believe they move to other parts of the body, rather than being destroyed.
"Exercise is a form of stress and more vigorous exercise creates more physiological stress which causes physiological and biochemical changes in the body. To tackle the potential threats these changes highlight, the immune cells may simply move out of the blood stream to the lungs, for example.
"This still leaves our bodies vulnerable to infections and, generally speaking, the more strenuous the exercise, the longer it takes for the immune system to return to normal.
"Epidemiological evidence suggests that regular moderate exercise protects against upper respiratory illnesses, like the common cold, whereas regular intense exercise increases the risk of upper respiratory illnesses."
Dr Neubauer said the research suggested most people only need carbohydrates during high-intensity or prolonged exercise of 90 minutes or more.
"The consumption of carbohydrates before and during strenuous exercise not only improves endurance performance, but it can also minimise exercise-related immune disturbances," he said.
"Between 30 and 60 grams of carbohydrates every hour during exercise help to support normal immune function. Examples of carbohydrates that could be consumed during exercise include carbohydrate-containing fluids, gels and bars consisting of different carbohydrates such as glucose and fructose. Alternatively, bananas may also do the job.
"As general advice for people who train for and participate in endurance events, any products should be tested if they are tolerated in the field.
"Consuming carbohydrates in the first few hours immediately after strenuous exercise also helps to restore immune function. This is especially important in situations where the recovery duration between two consecutive exercise sessions is short, which is often the case for athletes."
The researches did not find sufficient evidence to recommend 'immune-boosting' supplements, for example antioxidants.
"A diversified and well-balanced diet is most likely sufficient to help maintain immune function following longer-term exercise training.
"Sleep is recognised as important for maintaining immune function. However more research is needed to understand the influence of sleep on immunity in athletes."
A new study led by American Cancer Society researchers in collaboration with leading experts concludes that physical activity should be routinely assessed during the doctor-patient encounter, and that clinicians should design in collaboration with their patients a detailed physical activity plan with goals that should be set and monitored. The study uses concepts from public health and behavioral economics to provide practical advice to clinicians on effective counseling to patients.
The study appears early online in CA: A Cancer Journal for Clinicians. Below are highlights of the study:
- Despite abundant evidence linking physical inactivity to increased risk for numerous chronic conditions, such as some types of cancer, heart disease, type 2 diabetes, stroke, and even depression, physical inactivity is prevalent in modern society.
- In the United States, 51% of adults report not meeting aerobic physical activity guidelines, while objective measurement using accelerometers finds about 96.5% of adults ages 20 to 59 years do not meet those guidelines.
- The study, led by Kerem Shuval, PhD, and Tammy Leonard, PhD reports that because physicians' advice is respected and physician-patient encounters are frequent, these meetings can be used to provide consistent and comprehensive physical activity counseling, which may be an important vehicle for reducing the risk of chronic diseases and premature death.
- Physical activity should be routinely assessed at the clinic visit, a detailed physical activity plan should be jointly designed with the patient, and goals should be set and monitored.
- Specific strategies should be provided to patients to overcome impediments to activity. Both conscious and unconscious factors affect patients' behaviors and should be taken into account by the clinician and patient.
- Although the primary care setting is an important avenue to pursue physical activity promotion, it is not the only one. Policies aimed at changing the environment to one that is conducive to an active lifestyle are necessary to encourage sustainable changes.
What if you could lose weight and reduce your risk of life-threatening disease without any changes in what you eat -- other than a five-day special diet once every few months?
That's what happened for 71 adults who were placed on three cycles of a low-calorie, "fasting-mimicking" diet. The phase II trial, conducted by researchers at the USC Leonard Davis School of Gerontology, demonstrated a host of benefits from the regimen.
The diet reduced cardiovascular risk factors including blood pressure, signs of inflammation (measured by C-reactive protein levels), as well as fasting glucose and reduced levels of IGF-1, a hormone that affects metabolism. It also shrank waistlines and resulted in weight loss, both in total body fat and trunk fat, but not in muscle mass.
In effect, the diet reduced the study participants' risks for cancer, diabetes, heart disease and other age-related diseases, according to the findings published Feb. 15 in Science Translational Medicine.
"This study provides evidence that people can experience significant health benefits through a periodic, fasting-mimicking diet that is designed to act on the aging process," said Valter Longo, director of the USC Longevity Institute and a professor of biological sciences for USC Davis and Dornsife. "Prior studies have indicated a range of health benefits in mice, but this is the first randomized clinical trial with enough participants to demonstrate that the diet is feasible, effective and safe for humans.
"Larger FDA studies are necessary to confirm its effects on disease prevention and treatment," he added.
One hundred people participated in the trial from April 2013 to July 2015. The participants, ages 20 to 70 and all generally healthy, were divided into two groups for the randomized trial.
Participants in the first group, the control group, were asked to continue their normal eating habits for three months. People in the second group were placed on a three-month test of the fasting-mimicking diet.
Those on the special diet were required to eat food products supplied by the nutrition company L-Nutra during the fasting periods of five days each month. The diet, which was designed to mimic the results of a water-only fast, allowed for participants to consume between 750 and 1,100 calories per day. The meals for the fast-mimicking diet contained precise proportions of proteins, fats and carbohydrates.
After three months, participants in the control group were moved onto the special diet.
The researchers found that participants on the fasting-mimicking diet lost an average of about 6 pounds. Their waistlines shrank by 1 to 2 inches. Their systolic blood pressure, which was in the normal range when the study began, dropped by 4.5 mmHG, while their diastolic blood pressure dropped by 3.1 mmHg. Also, their levels of IGF-1 dropped to between 21.7 ng/mL and 46.2 ng/mL, reaching a range associated with lower cancer risk.
"After the first group completed their three months on the fasting diet, we moved over participants in the control group to see if they also would experience similar results," Longo said. "We saw similar outcomes, which provides further evidence that a fasting-mimicking diet has effects on many metabolic and disease markers. Our mouse studies using a similar fasting-mimicking diet indicate that these beneficial effects are caused by multi-system regeneration and rejuvenation in the body at the cellular and organ levels.
"Our participants retained those effects, even when they returned to their normal daily eating habits," he added.
The researchers also noted that participants considered "at risk" because they had risk factors such as high IGF-1, cholesterol, blood pressure or blood sugar levels, made significant progress toward better health.
For example, baseline fasting glucose levels for participants with high blood sugar levels (putting them at risk for diabetes) dropped into the healthy range, below 99 mg/dl -- but these levels didn't drop among participants who already had healthy levels at the beginning of the study. Cholesterol was reduced by 20 mg/dl in those with high cholesterol levels, and by about 5 mg/dl in all participants.
"Fasting seems to be the most beneficial for patients who have the great risk factors for disease, such as those who have high blood pressure or pre-diabetes or who are obese," Longo said.
The researchers had invited participants in the study for one last set of tests three months later, at the end of the diet. The research team found that the beneficial effects -- from weight loss, smaller waistlines and lower glucose, blood pressure and IGF-1 levels -- were sustained.
The next step for researchers is a large, FDA phase III clinical trial to test the FMD on patients diagnosed with age-related diseases or at high risk for them. The researchers said further investigation will determine whether the benefits of the diet can continue for several months.