Friday, March 29, 2013

Salt is making us sick


The love affair between U.S. residents and salt is making us sick: high sodium intake increases blood pressure, and leads to higher rates of heart attack and strokes. Nonetheless, Americans continue to ingest far higher amounts of sodium than those recommended by physicians and national guidelines.

A balanced review of the relevant literature has been published in the March 27, 2013 edition of The New England Journal of Medicine. Theodore A. Kotchen, M.D., professor of medicine (endocrinology), and associate dean for clinical research at the Medical College of Wisconsin, is the lead author of the article.

Dr. Kotchen cites correlations between blood pressure and salt intake in a number of different studies; typically, the causation between lowering salt intake and decreased levels of blood pressure occur in individuals who have been diagnosed with hypertension. Although not as pronounced, there is also a link between salt intake and blood pressure in non-hypertensive individuals. Additionally, recent studies have demonstrated that a reduced salt intake is associated with decreased cardiovascular disease and decreased mortality.

In national studies in Finland and Great Britain, instituting a national salt-reduction program led to decreased sodium intake. In Finland, the resulting decrease in systolic and diastolic blood pressures corresponded to a 75 – 80 percent decrease in death due to stroke and coronary heart disease. Neverthelesss, not all investigators concur with population-based recommendations to lower salt intake, and the reasons for this position are reviewed.

"Salt is essential for life, but it has been difficult to distinguish salt need from salt preference," said Dr. Kotchen. "Given the medical evidence, it seems that recommendations for reducing levels of salt consumption in the general population would be justifiable at this time." However, in terms of safety, the lower limit of salt consumption has not beeen clearly identified. In certain patient groups, less rigorous targets for salt reduction may be appropriate.

Eating more fiber may lower risk of first-time stroke



Study Highlights:

- Eating foods with more fiber was linked to a lower risk of first-time stroke.
- Every seven-gram increase in total dietary fiber was associated with a 7 percent lower risk of first-time stroke.
- The results reinforce the importance of a diet that includes at least 25 grams of fiber daily.

Eating more fiber may decrease your risk of first-time stroke, according to new research in the American Heart Association journal Stroke.

Dietary fiber is the part of the plant that the body doesn’t absorb during digestion. Fiber can be soluble, which means it dissolves in water, or insoluble.

Previous research has shown that dietary fiber may help reduce risk factors for stroke, including high blood pressure and high blood levels of low-density lipoprotein (LDL) “bad” cholesterol.

In the new study, researchers found that each seven-gram increase in total daily fiber intake was associated with a 7 percent decrease in first-time stroke risk. One serving of whole wheat pasta, plus two servings of fruits or vegetables, provides about 7 grams of fiber, researchers said.

“Greater intake of fiber-rich foods – such as whole-grains, fruits, vegetables and nuts – are important for everyone, and especially for those with stroke risk factors like being overweight, smoking and having high blood pressure,” Diane Threapleton, M.Sc., and Ph.D. candidate at the University of Leeds’ School of Food Science & Nutrition in Leeds, United Kingdom.

Researchers analyzed eight studies published between 1990-2012. Studies reported on all types of stroke with four specifically examining the risk of ischemic stroke, which occurs when a clot blocks a blood vessel to the brain. Three assessed hemorrhagic stroke, which occurs when a blood vessel bleeds into the brain or on its surface.

Findings from the observational studies were combined and accounted for other stroke risk factors like age and smoking.

The results were based on total dietary fiber. Researchers did not find an association with soluble fiber and stroke risk, and lacked enough data on insoluble fiber to make any conclusions.

The average daily fiber intake among U.S. adults is lower than the American Heart Association’s recommendation of at least 25 grams per day. Six to eight servings of grains and eight to 10 servings of fruits and vegetables can provide the recommended amount.

Most people do not get the recommended level of fiber, and increasing fiber may contribute to lower risk for strokes,” Threapleton said. “We must educate consumers on the continued importance of increasing fiber intake and help them learn how to increase fiber in their diet.”
In the United States, stroke is the fourth leading cause of death, killing more than 137,000 people annually. Among survivors, the disease is a leading cause of disability.

In addition to following a nutritious diet, the American Heart Association recommends being physically active and avoiding tobacco to help prevent stroke and other heart and blood vessel diseases.

Tuesday, March 26, 2013

Link between low doses of vitamin D and adverse pregnancy outcomes



There is a link between vitamin D insufficiency and adverse health outcomes such as gestational diabetes and preeclampsia in mothers-to-be and low birth weight in newborns, suggests a paper published on bmj.com today.

Vitamin D insufficiency has been associated with a number of adverse health outcomes and has been recognised as a public health concern. Plus, observational data has suggested a link between low vitamin D and increased risk of adverse pregnancy outcomes (such as gestational diabetes, preeclampsia, risk of infections, caesarean section and foetal growth restriction). Knowledge of these associations is however limited.

Literature on this topic is growing rapidly. As such, researchers from the University of Calgary in Canada carried out a systematic review and meta-analysis of all existing evidence on the effect of vitamin D concentration on pregnancy and birth outcomes.

Data from 31 studies were included in the analysis - all published between 1980 and 2012 with between 95 and 1,100 participants. Differences in study design and quality were taken into account to minimise bias.

Results showed that pregnant women with low levels of 5-OH vitamin D were more likely to develop gestational diabetes (odds ratio of 0.49), had an increased chance of developing preeclampsia (odds ratio of 0. 79) and an increased chance of giving birth to a baby small for gestational age (odds ratio of 0.85). No significant differences were found in birth length and head circumference.

The researchers say these results are "concerning" given recent evidence that vitamin D insufficiency is common during pregnancy, especially among high risk women, particularly vegetarians, women with limited sun exposure and ethnic minorities with darker skin.

The researchers conclude that the findings identify a significant association, but there remains a need for large, well-designed randomized controlled trials to determine whether "strategies to optimize vitamin D concentration are effective in improving pregnancy and neonatal outcomes". They also suggest that future studies should look at the dose-response relationship between vitamin D supplements and adverse health outcomes.

In an accompanying editorial, Dr Lucas from the National Centre for Epidemiology and Population Health at the Australian National University says that the findings of this study support a goal of vitamin D sufficiency for all pregnant women. She says that "supplements, diet and sunlight exposure" are all influences which "should be used together, with care". Dr Lucas adds that a previous editorial called for large well designed controlled trials "to clarify the causal association" which she believes is needed to find the magnitude of importance between vitamin D and pregnancy.

Protein-rich breakfasts prevent unhealthy snacking in the evening



Breakfast might be the most important meal of the day, but up to 60 percent of American young people consistently skip it. Now, Heather Leidy, an assistant professor in the Department of Nutrition and Exercise Physiology, says eating a breakfast rich in protein significantly improves appetite control and reduces unhealthy snacking on high-fat or high-sugar foods in the evening, which could help improve the diets of more than 25 million overweight or obese young adults in the U.S.

Leidy is the first to examine the impact of breakfast consumption on daily appetite and evening snacking in young people who habitually skip breakfast. In her study, 20 overweight or obese adolescent females ages 18-20 either skipped breakfast, consumed a high-protein breakfast consisting of eggs and lean beef, or ate a normal-protein breakfast of ready-to-eat cereal. Every breakfast consisted of 350 calories and was matched for dietary fat, fiber, sugar and energy density. The high-protein breakfast contained 35 grams of protein. Participants completed questionnaires and provided blood samples throughout the day. Prior to dinner, a brain scan using functional magnetic resonance imaging (fMRI) was performed to track brain signals that control food motivation and reward-driven eating behavior.

The consumption of the high-protein breakfast led to increased fullness or "satiety" along with reductions in brain activity that is responsible for controlling food cravings. The high-protein breakfast also reduced evening snacking on high-fat and high-sugar foods compared to when breakfast was skipped or when a normal protein, ready-to-eat cereal breakfast was consumed, Leidy said.

"Eating a protein-rich breakfast impacts the drive to eat later in the day, when people are more likely to consume high-fat or high-sugar snacks," Leidy said. "These data suggest that eating a protein-rich breakfast is one potential strategy to prevent overeating and improve diet quality by replacing unhealthy snacks with high quality breakfast foods."

People who normally skip breakfast might be skeptical about consuming food in the morning, but Leidy says it only takes about three days for the body to adjust to eating early in the day. Study participants ate egg and beef-based foods such as burritos or egg-based waffles with applesauce and a beef sausage patty as part of a high-protein breakfast; Leidy also suggests eating plain Greek yogurt, cottage cheese or ground pork loin as alternatives to reach the 35 grams of protein.

Future research will examine whether regularly consuming high-protein breakfasts improves body weight management in young people.


Thursday, March 21, 2013

Energy drinks may increase blood pressure, disturb heart rhythm


Energy drinks may increase blood pressure and disturb your heart’s natural rhythm, according to research presented at the American Heart Association’s Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions.

Researchers analyzed data from seven previously published observational and interventional studies to determine how consuming energy drinks might impact heart health.

In the first part of the pooled analysis, the researchers examined the QT interval of 93 people who had just consumed one to three cans of energy drinks. They found that the QT interval was
Energy drinks may increase blood pressure and disturb your heart’s natural rhythm, according to research presented at the American Heart Association’s Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions.

Researchers analyzed data from seven previously published observational and interventional studies to determine how consuming energy drinks might impact heart health.

In the first part of the pooled analysis, the researchers examined the QT interval of 93 people who had just consumed one to three cans of energy drinks. They found that the QT interval was 10 milliseconds longer for those who had consumed the energy drinks. The QT interval describes a segment of the heart’s rhythm on an electrocardiogram; when prolonged, it can cause serious irregular heartbeats or sudden cardiac death.

“Doctors are generally concerned if patients experience an additional 30 milliseconds in their QT interval from baseline,” said Sachin A. Shah, Pharm.D., lead author and assistant professor at University of the Pacific in Stockton, Calif.

“QT prolongation is associated with life-threatening arrhythmias. The finding that energy drinks could prolong the QT, in light of the reports of sudden cardiac death, warrants further investigation.” said Ian Riddock, M.D., a co-author and director of preventive cardiology at the David Grant Medical Center, Travis Air Force Base, Calif.

Researchers also found that the systolic blood pressure, the top number in a blood pressure reading, increased an average of 3.5 points in a pool of 132 participants.

“The correlation between energy drinks and increased systolic blood pressure is convincing and concerning, and more studies are needed to assess the impact on the heart rhythm.” Shah said. “Patients with high blood pressures or long QT syndrome should use caution and judgment before consuming an energy drink.

“Since energy drinks also contain caffeine, people who do not normally drink much caffeine might have an exaggerated increase in blood pressure.”

The pooled studies included healthy, young patients 18-45 years old. “People with health concerns or those who are older might have more heart-related side effects from energy drinks”, said Shah.

10 milliseconds longer for those who had consumed the energy drinks. The QT interval describes a segment of the heart’s rhythm on an electrocardiogram; when prolonged, it can cause serious irregular heartbeats or sudden cardiac death.

“Doctors are generally concerned if patients experience an additional 30 milliseconds in their QT interval from baseline,” said Sachin A. Shah, Pharm.D., lead author and assistant professor at University of the Pacific in Stockton, Calif.

“QT prolongation is associated with life-threatening arrhythmias. The finding that energy drinks could prolong the QT, in light of the reports of sudden cardiac death, warrants further investigation.” said Ian Riddock, M.D., a co-author and director of preventive cardiology at the David Grant Medical Center, Travis Air Force Base, Calif.

Researchers also found that the systolic blood pressure, the top number in a blood pressure reading, increased an average of 3.5 points in a pool of 132 participants.

“The correlation between energy drinks and increased systolic blood pressure is convincing and concerning, and more studies are needed to assess the impact on the heart rhythm.” Shah said. “Patients with high blood pressures or long QT syndrome should use caution and judgment before consuming an energy drink.

“Since energy drinks also contain caffeine, people who do not normally drink much caffeine might have an exaggerated increase in blood pressure.”

The pooled studies included healthy, young patients 18-45 years old. “People with health concerns or those who are older might have more heart-related side effects from energy drinks”, said Shah.

Wednesday, March 20, 2013

Latest Health Research


New study: strong anti-cancer properties of soybeans

How extra virgin olive oil protects against Alzheimers

Heart-Healthy Lifestyle Also Reduces Cancer Risk


Adhering to six or seven of the factors reduced the risk of cancer by 51 percent, compared with participants who met none of the factors. Meeting four factors led to a 33 percent risk reduction and one or two 21 percent.



Vitamin D Supplementation Improves Muscle Efficiency

Coffee holds the key to a longer life?

Aspirin May Lower Melanoma Risk

Green tea, coffee may help lower stroke risk

People who drank at least one cup of coffee daily had about a 20 percent lower risk of stroke compared to those who rarely drank it.

People who drank two to three cups of green tea daily had a 14 percent lower risk of stroke and those who had at least four cups had a 20 percent lower risk, compared to those who rarely drank it.

People who drank at least one cup of coffee or two cups of green tea daily had a 32 percent lower risk of intracerebral hemorrhage, compared to those who rarely drank either beverage. (Intracerebral hemorrhage happens when a blood vessel bursts and bleeds inside the brain. About 13 percent of strokes are hemorrhagic.)


Hot Dogs Could Kill You (So Can Salami and Ham)

Anyone who eats over 40 grams a day of sausage products or other kinds of processed meat is asking for trouble: the risk of mortality increases by 18 percent for every 50 grams of processed meat per day.

Probiotics reduce stress-induced intestinal flare-ups

Resveratrol directly activates a protein that promotes health

Short Bouts Of Exercise Boost Self Control

A stimulating environment may protect against Alzheimers

Exercise Key to Good Sleep

Why fish is so good for you

Walking Away from Back Pain

The Importance Of Eating Your Greens

Colonoscopy Reduces Advanced Cancer Risk by 70 Percent

Moving about more could be more important than vigorous exercise

Maintaining Physical Activity Essential For Health

Declines in high levels of recreational exercise and other physical
activity can potentially account for between 12-30% of the increase
in obesity, hypertension, diabetes, and heart disease observed over
the sample period.

Pessimism about the future may lead to longer, healthier life

Older people who have low expectations for a satisfying future may be more likely to live longer, healthier lives than those who see brighter days ahead, according to new research published by the American Psychological Association.


Omega-3 Supplements May Prevent Skin Cancer

Mediterranean Diet Helps Cut Risk of Heart Attack, Stroke


Mediterranean diet supplemented with extra-virgin olive oil or tree nuts reduces by 30 percent the risk of suffering a cardiovascular death, a myocardial infarction or a stroke.

New study: strong anti-cancer properties of soybeans



First study to report that proteins found in soybeans, could inhibit growth of colon, liver and lung cancers, published in Food Research International

Soybean meal is a bi-product following oil extraction from soybean seeds. It is rich in protein, which usually makes up around 40% of the nutritional components of the seeds and dependent on the line, and can also contain high oleic acid (a monounsaturated omega-9 fatty acid).

The study looked at the role soybeans could have in the prevention of cancer. Using a variety of soybean lines which were high in oleic acid and protein, the researchers looked to monitor bioactivity between the peptides derived from the meals of soybean and various types of human cancer cells.

The study showed that peptides derived from soybean meal significantly inhibited cell growth by 73% for colon cancer, 70% for liver cancer and 68% for lung cancer cells using human cell lines. This shows that the selected high oleic acid soybean lines could have a potential nutraceutical affect in helping to reduce the growth of several types of cancer cells.

How extra virgin olive oil protects against Alzheimer's disease



The mystery of exactly how consumption of extra virgin olive oil helps reduce the risk of Alzheimer's disease (AD) may lie in one component of olive oil that helps shuttle the abnormal AD proteins out of the brain, scientists are reporting in a new study. It appears in the journal ACS Chemical Neuroscience.

Amal Kaddoumi and colleagues note that AD affects about 30 million people worldwide, but the prevalence is lower in Mediterranean countries. Scientists once attributed it to the high concentration of healthful monounsaturated fats in olive oil — consumed in large amounts in the Mediterranean diet. Newer research suggested that the actual protective agent might be a substance called oleocanthal, which has effects that protect nerve cells from the kind of damage that occurs in AD. Kaddoumi's team sought evidence on whether oleocanthal helps decrease the accumulation of beta-amyloid (Aβ) in the brain, believed to be the culprit in AD.

They describe tracking the effects of oleocanthal in the brains and cultured brain cells of laboratory mice used as stand-ins for humans in such research. In both instances, oleocanthal showed a consistent pattern in which it boosted production of two proteins and key enzymes believed to be critical in removing Aβ from the brain. "Extra-virgin olive oil-derived oleocanthal associated with the consumption of Mediterranean diet has the potential to reduce the risk of AD or related neurodegenerative dementias," the report concludes.

Heart-Healthy Lifestyle Also Reduces Cancer Risk


Following the American Heart Association's Life's Simple 7 steps to reduce your risk for heart disease can also help prevent cancer, according to new research in the American Heart Association journal Circulation.

"We were gratified to know adherence to the Life's Simple 7 goals was also associated with reduced incidence of cancer," said Laura J. Rasmussen-Torvik, an assistant professor at the Northwestern University Feinberg School of Medicine in Chicago and lead author of the study. "This can help health professionals provide a clear, consistent message about the most important things people can do to protect their health and lower their overall risk for chronic diseases."

Adhering to six or seven of the factors reduced the risk of cancer by 51 percent, compared with participants who met none of the factors. Meeting four factors led to a 33 percent risk reduction and one or two 21 percent.

Life's Simple 7 is part of the association's My Life Check campaign that advises Americans to adhere to seven factors for a healthy heart:

Being physically active
Keeping a healthy weight
Eating a healthy diet
Maintaining healthy cholesterol levels
Keeping blood pressure down
Regulating blood sugar levels
Not smoking

When smoking status was not considered, participants who met five or six of the remaining six factors had a 25 percent lower cancer risk than those who met none.

"We're trying to help promote a comprehensive health message," Rasmussen-Torvik said. "Quitting smoking is very important, but there are other factors you need to be aware of if you want to live a healthy life."

Participants included 13,253 white and African-American men and women in the ongoing Atherosclerosis Risk in Communities Study, launched in 1987 in four U.S. communities. Participants were interviewed and examined at the start of the study to determine which health factors they met or followed.

About 20 years later, the researchers reviewed cancer registries and hospital records and determined that 2,880 of the participants ended up with cancer, primarily of the lung, colon or rectum, prostate and breast.

Non-melanoma skin cancers were not considered, and researchers didn't look at cancer risk factor changes over time.

"This adds to the strong body of literature suggesting that it's never too late to change, and that if you make changes like quitting smoking and improving your diet, you can reduce your risk for both cardiovascular disease and cancer," Rasmussen-Torvik said.

Tuesday, March 19, 2013

Vitamin D Supplementation Improves Muscle Efficiency



New research shows for the first time a link between vitamin D levels and muscle efficiency. Vitamin D supplementation may also be effective in improving skeletal muscle function. This study is presented today at the Society for Endocrinology annual conference in Harrogate, UK. The findings may explain the physical fatigue commonly experienced by patients with vitamin D deficiency, with broad implications for a large section of society

Vitamin D is a hormone produced in the skin using energy from sunlight, and to a lesser extent derived from dietary sources. Vitamin D deficiency is a significant public health problem as diagnosed cases are on the rise and the hormone is essential for good bone health. Alongside poor bone health, muscle fatigue is a common symptom in vitamin D deficient patients. This fatigue could be due to a problem in the mitochondria: the 'power stations' within each cell of the body. Mitochondria use glucose and oxygen to make energy in a form that can be used to run the cell (an energy-rich molecule called ATP). Muscle cells need large amounts of ATP for movement and they use phosphocreatine as a ready and available energy source to make ATP. The mitochondria also replenish this phosphocreatine store after muscle contraction. Measurement of the time taken to replenish the phosphocreatine store is a measure of mitochondrial efficiency: better mitochondrial function is associated with shorter phosphocreatine recovery times.

Researchers from Newcastle University, led by Dr Akash Sinha who also works within the Newcastle upon Tyne Hospitals NHS Foundation Trust, investigated phosphocreatine recovery times in patients with vitamin D deficiency. They employed a non-invasive magnetic resonance scan to measure phosphocreatine dynamics in response to exercise in the calf muscles of 12 patients with severe vitamin D deficiency before and after treatment with vitamin D. This is the first time a study of this kind has been conducted.

The team found that phosphocreatine recovery significantly improved after the patients took a fixed dose of oral vitamin D for 10-12 weeks (average phosphocreatine recovery half time decreased from 34.4sec to 27.8sec, p<0.001). All patients reported an improvement in symptoms of fatigue following supplementation. In a parallel study, the group demonstrated that low Vitamin D levels were associated with reduced mitochondrial function (r=-0.41, p=0.009).

The research shows for the first time that vitamin D levels are correlated with muscle efficiency, and that muscle aerobic metabolism improves with Vitamin D supplementation. Whilst this is a small study, it establishes clear proof of principle and (for the first time) a link between vitamin D and mitochondria in man. The mechanisms underpinning this effect are an avenue for future research by the group, who also aim to establish whether vitamin D supplementation could alleviate frailty in the elderly or improve the exercise capacity of athletes.

Study leader Dr Akash Sinha, Clinical Research Fellow at Newcastle University and Newcastle upon Tyne Hospitals NHS Foundation Trust said: "This is the first time a link has been shown between vitamin D status and muscle aerobic function. To do so we used a non-invasive scan to get a unique biochemical perspective on muscle mitochondrial metabolism during exercise: a window into what is really going on in the muscle as it works

"Patients with vitamin D deficiency often experience symptoms of muscle fatigue. Our findings in a small group of patients with very low vitamin D levels show that muscle efficiency significantly improves when vitamin D status is improved.''

"We'll need further research in more patients to work out how this is happening and whether non-deficient patients can benefit from this too."

Monday, March 18, 2013

Coffee holds the key to a longer life?


The elderly inhabitants of Ikaria, the Greek island, boast the highest rates of longevity in the World, and many scientists turn to them when looking to discover the 'secrets of a longer life'. In a new study in Vascular Medicine, published by SAGE, researchers investigating cardiovascular health believe that a cup of boiled Greek coffee holds the clue to the elderly islanders' good health.

Only 0.1% of Europeans live to be over 90, yet on the Greek island of Ikaria, the figure is 1%. This is recognized as one of the highest longevity rates anywhere – and the islanders tend to live out their longer lives in good health.

Gerasimos Siasos, a medical doctor and professor at the University of Athens Medical School, Greece set out with his team to find out whether the elderly population's coffee drinking had an effect on their health. In particular, the researchers investigated links between coffee-drinking habits and the subjects' endothelial function. The endothelium is a layer of cells that lines blood vessels, which is affected both by aging and by lifestyle habits (such as smoking). The team homed in on coffee because recent studies suggest that moderate coffee consumption may slightly reduce the risks of coronary heart disease, and that it may also have a positive impact on several aspects of endothelial health.

From a sample of 673 Ikarians aged over 65 who lived on the island permanently, the researchers randomly selected 71 men and 71 women to take part in the study. Medical staff used health checks (for high blood pressure, diabetes, etc.) and questionnaires to get more detail on the participants' medical health, lifestyles and coffee drinking, in addition to testing their endothelial function.

The researchers investigated all types of coffee taken by participants – but interestingly more than 87% of those in the study consumed boiled, Greek coffee daily. More importantly, subjects consuming mainly boiled Greek coffee had better endothelial function than those who consumed other types of coffee. Even in those with high blood pressure, boiled Greek coffee consumption was associated with improved endothelial function, without worrying impacts on blood pressure.

"Boiled Greek type of coffee, which is rich in polyphenols and antioxidants and contains only a moderate amount of caffeine, seems to gather benefits compared to other coffee beverages," Siasos concludes.

The new study provides a new connection between nutritional habits and cardiovascular health. Given the extent of coffee drinking across the world, and the fact that even small health effects of at least one type of coffee could have a large impact on public health, this study provides an interesting starting point. However, further studies are needed to document the exact beneficial mechanisms of coffee on cardiovascular health.

Sunday, March 17, 2013

Aspirin May Lower Melanoma Risk


A new study has found that women who take aspirin have a reduced risk of developing melanoma -- and that the longer they take it, the lower the risk. The findings suggest that aspirin's anti-inflammatory effects may help protect against this type of skin cancer. The study is published early online in Cancer, a peer-reviewed journal of the American Cancer Society.

In the Women's Health Initiative, researchers observed US women aged 50 to 79 years for an average of 12 years and noted which individuals developed cancer. At the beginning of the study, the women were asked which medications they took, what they ate, and what activities they performed.

When Jean Tang MD, PhD, of Stanford University School of Medicine in Palo Alto, and her colleagues analyzed available data from 59,806 Caucasian women in the study, they found that women who took more aspirin were less likely to develop melanoma skin cancer during the 12 years of follow up. Overall, women who used aspirin had a 21 percent lower risk of melanoma relative to non-users. Each incremental increase in duration of aspirin use (less than one year of use, one to four years of use, and five or more years of use) was associated with an 11 percent lower risk of melanoma. Thus, women who used aspirin for five or more years had a 30 percent lower melanoma risk than women who did not use aspirin. The researchers controlled for differences in pigmentation, tanning practices, sunscreen use, and other factors that may affect skin cancer risk.

"Aspirin works by reducing inflammation and this may be why using aspirin may lower your risk of developing melanoma," said Dr. Tang. Other pain medications, such as acetaminophen, did not lower women's melanoma risk. Dr. Tang noted that the findings support the design of a clinical trial to directly test whether aspirin can be taken to prevent melanoma.

Two cups of coffee a day=risk of low birth weight


Drinking just two cups of coffee a day is associated with the risk of low birth weight. Researchers at Sahlgrenska Academy, University of Gothenburg, Sweden, have conducted a study on 59,000 women in collaboration with the Norwegian Institute of Public Health.

Expectant mothers who consume caffeine, usually by drinking coffee, are more likely to have babies with lower birth weight than anticipated, given their gestational age. Researchers at Sahlgrenska Academy, University of Gothenburg, conducted a study on 59,000 pregnant Norwegian women in collaboration with the Norwegian Institute of Public Health.

"The correlation between intake of caffeine and fetal growth was established even among women who followed the official recommendation that they limit caffeine consumption to 200 milligrams a day (two cups of coffee)," researcher Verena Sengpiel says.

The medical term used in this connection is "small for gestational age" (SGA), which is associated with an elevated risk of morbidity and death.

The new results are consistent with previous international studies but are based on a considerably larger cohort. The participants were healthy and had uncomplicated pregnancies until delivery, while the results were adjusted for age, smoking, body mass index, nicotine consumption, alcohol use and other variables that affect fetal growth.

"We need to stress that our study did not examine whether caffeine is the specific mechanism substance by which responsible for the fetus is being at greater risk of low birth weight," Ms. Sengpiel says. "Nor did we look at whether these babies actually had special health problems during the neonatal period. Additional research is needed before we can say for sure what our finding actually means for pregnant women and their babies."

The other purpose of the study, which is being published in BMC Medicine, was to determine whether women who consumed caffeine during pregnancy were more likely to give birth prematurely. Such a correlation could not be established.

The research team is hoping to conduct more in-depth studies about the cause-effect relationship between caffeine use and SGA, as well as any correlation between SGA and neonatal morbidity and death.

Saturday, March 16, 2013

High-fat dairy products linked to poorer breast cancer survival


Patients who consume high-fat dairy products following breast cancer diagnosis increase their chances of dying from the disease years later, according to a study by Kaiser Permanente researchers.

The study, published in the Journal of the National Cancer Institute, is the first to examine the relationship between high-fat and low-fat dairy consumption following a diagnosis of breast cancer and long-term breast cancer survival.

Previous studies have shown that higher lifetime exposure to estrogen is a causal pathway to breast cancer. Estrogen levels are believed to be elevated in dairy products consumed in the Western world, because most of its milk comes from pregnant cows. Estrogenic hormones reside primarily in fat, so levels are higher in high-fat than in low-fat dairy products.

The researchers studied a cohort of women who were diagnosed with early-stage, invasive breast cancer between 1997 and 2000, primarily from Kaiser Permanente's Northern California region (83 percent) and the Utah Cancer Registry (12 percent).

Those consuming larger amounts of high-fat dairy (one serving or more per day) had "higher breast cancer mortality as well as higher all-cause mortality and higher non-breast cancer mortality," wrote lead author Candyce H. Kroenke, ScD, MPH, staff scientist with the Kaiser Permanente Division of Research, and co-authors.

"Specifically, women consuming one or more servings per day of high-fat dairy had a 64 percent higher risk of dying from any cause and a 49 percent increased risk of dying from their breast cancer during the follow-up period," said Kroenke. The category of high-fat dairy products researchers tracked included cream, whole milk, condensed or evaporated milk, pudding, ice cream, custard, flan, and also cheeses and yogurts that were not low-fat or non-fat.

In general, the women studied reported that they consumed low-fat milk and butter most often, and they consumed relatively limited amounts of low-fat dairy desserts, low-fat cheese and high-fat yogurt. Overall, low-fat dairy intake was greater (median 0.8 servings per day) than high-fat dairy (median 0.5 servings per day).

The study found an association between high-fat dairy and breast cancer mortality, but no association with low-fat dairy products and breast cancer outcomes.

"High-fat dairy is generally not recommended as part of a healthy diet," said senior author Bette J. Caan, DrPH, research scientist with the Kaiser Permanente Division of Research. "Switching to low-fat dairy is an easy thing to modify."

Women entered into the cohort approximately two years after their breast cancer diagnosis. At the beginning of the study, 1,893 women completed a self-administered food-frequency questionnaire, and 1,513 of these women completed a follow-up questionnaire six years later. They were followed for 12 years on average following study entry.

The women were asked how often they consumed dairy foods during the previous year; what portion sizes they generally consumed; which products they ate, including milk, cheese, dairy desserts, yogurt, and beverages made with milk (such as hot chocolate or lattes); and whether the dairy products were full fat, low fat or nonfat.

Of the total sample, 349 women had a recurrence of breast cancer and 372 died of any cause, 189 (50.8 percent) of them from breast cancer.

This research was part of the Life After Cancer Epidemiology (LACE) study, one of several efforts by investigators with the Kaiser Permanente Division of Research to consider the role of lifestyle factors such as nutrition, exercise and social support on long-term breast cancer survival and recurrence. While hundreds of studies have examined the role of lifestyle factors in cancer risk and prevention, this study is one of a small but growing number that focus on the role of lifestyle factors after a breast cancer diagnosis.

For example, the Pathways study of breast cancer survivorship, based at the Division of Research, is collecting and analyzing data about women's genetic background, tumor characteristics and lifestyle choices immediately after diagnosis. Findings from this study, along with the LACE study, are providing objective information to help guide women as they make decisions following a breast cancer diagnosis; among these findings are that soy decreases the risk of breast cancer recurrence, quality of life after diagnosis influences outcomes, and physical activity is beneficial.

Susan E. Kutner, MD, chair of the Kaiser Permanente Northern California Regional Breast Care Task Force, said that the new study bolsters the counseling that Kaiser Permanente gives breast cancer survivors about the importance of a low-fat diet, as well as exercise and weight management, in preventing recurrence of the disease. "Women have been clamoring for this type of information," Kutner said. "They're asking us, 'Tell me what I should eat?' With this information, we can be more specific about recommending low-fat dairy products."

Green tea, coffee may help lower stroke risk



Green tea and coffee may help lower your risk of having a stroke, especially when both are a regular part of your diet, according to research published in Stroke: Journal of the American Heart Association.

"This is the first large-scale study to examine the combined effects of both green tea and coffee on stroke risks," said Yoshihiro Kokubo, M.D., Ph.D., F.A.H.A., F.A.C.C., F.E.S.C., lead author of the study at Japan's National Cerebral and Cardiovascular Center. "You may make a small but positive lifestyle change to help lower the risk of stroke by adding daily green tea to your diet."

Researchers asked 83,269 Japanese adults about their green tea and coffee drinking habits, following them for an average 13 years. They found that the more green tea or coffee people drink, the lower their stroke risks.

People who drank at least one cup of coffee daily had about a 20 percent lower risk of stroke compared to those who rarely drank it.
People who drank two to three cups of green tea daily had a 14 percent lower risk of stroke and those who had at least four cups had a 20 percent lower risk, compared to those who rarely drank it.
People who drank at least one cup of coffee or two cups of green tea daily had a 32 percent lower risk of intracerebral hemorrhage, compared to those who rarely drank either beverage. (Intracerebral hemorrhage happens when a blood vessel bursts and bleeds inside the brain. About 13 percent of strokes are hemorrhagic.)
Participants in the study were 45 to 74 years old, almost evenly divided in gender, and were free from cancer and cardiovascular disease.

During the 13-years of follow-up, researchers reviewed participants' hospital medical records and death certificates, collecting data about heart disease, strokes and causes of death. They adjusted their findings to account for age, sex and lifestyle factors like smoking, alcohol, weight, diet and exercise.

Green tea drinkers in the study were more likely to exercise compared to non-drinkers.

Previous limited research has shown green tea's link to lower death risks from heart disease, but has only touched on its association with lower stroke risks. Other studies have shown inconsistent connections between coffee and stroke risks.

Initial study results showed that drinking more than two cups of coffee daily was linked to increasing coronary heart disease rates in age- and sex-adjusted analysis. But researchers didn't find the association after factoring in the effects of cigarette smoking — underscoring smoking's negative health impact on heart and stroke health.

A typical cup of coffee or tea in Japan was approximately six ounces. "However, our self-reported data may be reasonably accurate, because nationwide annual health screenings produced similar results, and our validation study showed relatively high validity." Kokubo said. "The regular action of drinking tea, coffee, largely benefits cardiovascular health because it partly keeps blood clots from forming."

Tea and coffee are the most popular drinks in the world after water, suggesting that these results may apply in America and other countries.

It's unclear how green tea affects stroke risks. A compound group known as catechins may provide some protection. Catechins have an antioxidant anti-inflammatory effect, increasing plasma antioxidant capacity and anti-thrombogenic effects.

Some chemicals in coffee include chlorogenic acid, thus cutting stroke risks by lowering the chances of developing type 2 diabetes. Further research could clarify how the interaction between coffee and green tea might help further lower stroke risks, Kokubo said.

Friday, March 15, 2013

Probiotics reduce stress-induced intestinal flare-ups


For those with irritable bowel syndrome who wonder if stress aggravates their intestinal disorder, a new University of Michigan Health System study shows it's not all in their head.

Researchers revealed that while stress does not cause IBS, it does alter brain-gut interactions and induces the intestinal inflammation that often leads to severe or chronic belly pain, loss of appetite and diarrhea.

Stress has a way of suppressing an important component called an inflammasome which is needed to maintain normal gut microbiota, but probiotics reversed the effect in animal models, according to findings published online ahead of print in Gastroenterology.

"The effect of stress could be protected with probiotics which reversed the inhibition of the inflammasome," says senior study author and gastroenterologist John Y. Kao, M.D., associate professor of internal medicine at the University of Michigan. "This study reveals an important mechanism for explaining why treating IBS patients with probiotics makes sense."

Probiotics are live bacteria that help grow the gut-dwelling "good" bacteria that keep pathogens in check, aid digestion and nutrient absorption and contribute to immune function.

U-M researchers including Chung Owyang, M.D., chief of the U-M Division of Gastroenterology, Gary Huffnagle, Ph.D., professor of pulmonary and critical care, and infectious disease expert Vincent Young, M.D., Ph.D., were able to identify the way stress significantly altered the composition of gut bacteria and the role of probiotics.

Maintaining healthy microbiota requires action by nucleotide-binding oligomerization domain protein-like receptors, pyrin-domain containing (NLRP)-6 inflammasomes. But when stressed, mice produced corticotropin-releasing hormone (CRH) that prevented inflammasomes from doing their job.

Inhibiting inflammosomes alters the composition of the gut, leading to intestinal inflammation. In the study, pretreatment with probiotic therapy reduced inflammation in mice with stress-induced small bowel inflammation.

"Additional clinical study is required to determine the optimal probiotic therapy," says Kao. "Patients can start living healthier lifestyles to improve their gut microbiota such as adding more fruits and vegetables to their diet, and looking for ways to keep stress in check."



Vitamin D supplements may help African Americans lower blood pressure



Vitamin D supplements significantly reduced blood pressure in the first large controlled study of African-Americans, researchers report in the American Heart Association journal Hypertension.

In the prospective trial, a three-month regimen of daily vitamin D increased circulating blood levels of vitamin D and resulted in a decrease in systolic blood pressure ranging from .7 to four mmHg (depending upon the dose given), compared with no change in participants who received a placebo.

Systolic blood pressure, the top and highest number in a reading, is pressure in the arteries when the heart beats. Diastolic blood pressure, the bottom and lower number, is pressure in the arteries between heart beats.

"Although this needs to be studied further, the greater prevalence of vitamin D deficiency among African-Americans may explain in part some of the racial disparity in blood pressure," said John P. Forman, M.D., M.Sc., lead author of the study and Assistant Professor of Medicine in the Renal Division and Kidney Clinical Research Institute at Brigham and Women's Hospital in Boston, Mass.

African-Americans have higher rates of hypertension and lower levels of circulating 25-hydroxyvitamin D (vitamin D3 or cholecalciferol) than the rest of the U.S. population. Few studies have included enough African-Americans to determine whether vitamin D supplements might reduce the racial disparity.

To explore this, researchers from seven major teaching hospitals conducted a four-arm, randomized, double-blinded study of 250 black adults. They tested blood pressure after a three-month regimen of daily vitamin D supplementation at one of three doses, and compared the findings with a group taking placebo vitamins:

Taking 1,000 units of vitamin D each day for three months was associated with a .7 mm Hg decrease in systolic blood pressure.
Taking 2,000 units was linked to a 3.4 mm Hg decrease.
Taking 4,000 units netted a 4 mm Hg drop.
Participants taking placebo supplements had an average increase of 1.7 mm Hg.
"The gains we saw were significant but modest," Forman said.

Furthermore, diastolic blood pressure didn't change in any of the four groups. In prospective studies, lower blood levels of 25-hydroxyvitamin D have been independently linked with an increased risk of developing hypertension.

"If vitamin D supplementation lowered blood pressure among African-Americans, its widespread use could have major public health benefits," said Andrew T. Chan, M.D., M.P.H., co-author of the study and Assistant Professor of Medicine in the Division of Gastroenterology at Massachusetts General Hospital.

Thursday, March 7, 2013

Hot Dogs Could Kill You (So Can Salami and Ham)


Anyone who eats over 40 grams a day of sausage products or other kinds of processed meat is asking for trouble: the risk of mortality increases by 18 percent for every 50 grams of processed meat per day. This is the result of a study conducted with around 450,000 participants by the Institute of Social and Preventive Medicine at the University of Zurich in collaboration with research colleagues from all over Europe.

“We estimate that three percent of all premature deaths can be attributed to the high consumption of processed meat,” summarizes Sabine Rohrmann from the Institute of Social and Preventive Medicine at the University of Zurich. Teaming up with research colleagues from ten countries, she has been studying the link between the consumption of processed meat and the risk of mortality as part of a Europe-wide study with around 450,000 participants.

People who eat a lot of processed meat such as sausage products, salami or ham run a higher risk of dying from cardiovascular disease or cancer. The problem is that carcinogenic substances such as nitrosamines form through salting, pickling or smoking, and these might be the cause of the increase in cancer mortality. However, processed meats are also rich in cholesterol and saturated fats, which are linked to an increased risk of cardiovascular disease.

Other lifestyle and dietary factors influence the link between the consumption of processed meat and the risk of illness or mortality: for instance, vegetarians often live more healthily than non-vegetarians, do more sport and are less likely to smoke. This also goes for the present study: The participants who eat the most processed meat also eat fewer fruit and vegetables, consume more alcohol and smoke more. But even taking these factors into account in the evaluation of the data, the core result of the study still proves to be true: People who eat over 40 grams of processed meat per day have an increased risk of mortality compared to those who eat fewer than 20 grams a day.


Resveratrol directly activates a protein that promotes health


A new study demonstrates what researchers consider conclusive evidence that the red wine compound resveratrol directly activates a protein that promotes health and longevity in animal models. What's more, the researchers have uncovered the molecular mechanism for this interaction, and show that a class of more potent drugs currently in clinical trials act in a similar fashion. Pharmaceutical compounds similar to resveratrol may potentially treat and prevent diseases related to aging in people, the authors contend.

These findings are published in the March 8 issue of Science.

For the last decade, the science of aging has increasingly focused on sirtuins, a group of genes that are believed to protect many organisms, including mammals, against diseases of aging. Mounting evidence has demonstrated that resveratrol, a compound found in the skin of grapes as well as in peanuts and berries, increases the activity of a specific sirtuin,SIRT1, that protects the body from diseases by revving up the mitochondria, a kind of cellular battery that slowly runs down as we age. By recharging the batteries, SIRT1 can have profound effects on health.

Mice on resveratrol have twice the endurance and are relatively immune from effects of obesity and aging. In experiments with yeast, nematodes, bees, flies and mice, lifespan has been extended.

"In the history of pharmaceuticals, there has never been a drug that binds to a protein to make it run faster in the way that resveratrol activates SIRT1," said David Sinclair, Harvard Medical School professor of genetics and senior author on the paper. "Almost all drugs either slow or block them."

In 2006, Sinclair's group published a study showing that resveratrol could extend the lifespan of mice, and the company Sirtris Pharmaceuticals, which was started by HMS researchers, was founded to make drugs more potent than resveratrol. (Sinclair is a co-founder of Sirtris, a GlaxoSmithKline company, and remains a scientific advisor. Sirtris currently has a number of sirtuin-activating compounds in clinical trials.)

But while numerous studies, from Sinclair's lab and elsewhere, underscored a direct causal link between resveratrol and SIRT1, some scientists claimed the studies were flawed.

The contention lay in the way SIRT1 was studied in vitro, using a specific chemical group attached to the targets of SIRT1 that fluoresces more brightly as SIRT1 activity increases. This chemical group, however, is synthetic and does not exist in cells or in nature, and without it the experiments did not work. As a response to this, a paper published in 2010 surmised that resveratrol's activation of SIRT1 was an experimental artifact, one that existed in the lab, but not in an actual animal. SIRT1 activity in mice was, the paper claimed, at best an indirect result of resveratrol, and perhaps even a sheer coincidence.

As a result, a debate erupted over the particular pathway that resveratrol and similar compounds affected. Does resveratrol directly activate SIRT1 or is the effect indirect? "We had six years of work telling us that this was most definitely not an artifact," said Sinclair. "Still, we needed to figure out precisely how resveratrol works. The answer was extremely elegant."

Sinclair and Basil Hubbard, then a doctoral student in the lab, teamed up with a group of researchers from both the National Institutes of Health and Sirtris Pharmaceuticals to address this question.

First, the team addressed the problem of the fluorescent chemical group. Why was it required for resveratrol to rev up SIRT1 in the test tube? Instead of dismissing the result as an artifact, the researchers surmised that the chemical might be mimicking molecules found naturally in the cell. These turned out to be a specific class of amino acid, the building blocks of proteins. In nature, there are three amino acids that resemble the fluorescent chemical group, one of which is tryptophan, a molecule abundant in turkey and notable for inducing drowsiness. When researchers repeated the experiment, swapping the fluorescing chemical group on the substrate with a tryptophan residue, resveratrol and similar molecules were once again able to activate SIRT1.

"We discovered a signature for activation that is in fact found in the cell and doesn't require these other synthetic groups," said Hubbard, first author of the study. "This was a critical result, which allowed us to bridge the gap between our biochemical and physiological findings.

"Next, we needed to identify precisely how resveratrol presses on SIRT1's accelerator," said Sinclair. The team tested approximately 2,000 mutants of the SIRT1 gene, eventually identifying one mutant that completely blocked resveratrol's effect. The particular mutation resulted in the substitution of a single amino acid residue, out of the 747 that make up SIRT1. The researchers also tested hundreds of other molecules from the Sirtris library, many of which are far more powerful than resveratrol, against this mutant SIRT1. All failed to activate it.

The authors propose a model for how resveratrol works: When the molecule binds, a hinge flips, and SIRT1 becomes hyperactive.

Although these experiments occurred in a test tube, once the researchers identified the precise location of the accelerator pedal on SIRT1—and how to break it—they could test their ideas in a cell. They replaced the normal SIRT1 gene in muscle and skin cells with the accelerator-dead mutant. Now they could test precisely whether resveratrol and the drugs in development work by tweaking SIRT1 (in which case they would not work) or one of the thousands of other proteins in a cell (in which they would work). While resveratrol and the drugs tested revved up mitochondria in normal cells (an effect caused activating by SIRT1), the mutant cells were completely immune.

"This was the killer experiment," said Sinclair. "There is no rational alternative explanation other than resveratrol directly activates SIRT1 in cells. Now that we know the exact location on SIRT1 where and how resveratrol works, we can engineer even better molecules that more precisely and effectively trigger the effects of resveratrol."


Short Bouts Of Exercise Boost Self Control



Short bouts of moderately intense exercise seem to boost self control, indicates an analysis of the published evidence in the British Journal of Sports Medicine.

The resulting increased blood and oxygen flow to the pre-frontal cortex may explain the effects, suggest the researchers.

They trawled medical research databases for studies looking at the impact of physical exercise on higher brain functions, such as memory, concentration, planning, and decision-making, in three groups: 6 to 12 year olds; 13 to 17 year olds; and 18 to 35 year olds.

They found 24 relevant studies published up to April 2012. Nineteen of these, involving 586 participants, addressed the impact of short bouts of exercise, and five, involving 358 participants, addressed the impact of regular exercise.

Regular exercise didn't seem to have much impact on higher brain functions, the analysis showed, but the studies were too few in number, and their results too inconsistent to enable firm conclusions to be drawn, caution the authors.

But short bouts of exercise did boost higher brain function in all three age groups. Only four studies looked at the impact of this type of exercise on working memory, but only in young adults, and the numbers were insufficient to draw conclusions on the impact.

But 12 of the 19 studies looked at self control, and the analysis indicated that short bouts of exercise did improve this higher brain function across all three age groups, registering a small to moderate impact.

This is particularly important for children and teens, because well developed higher brain functions are important for academic achievement and other aspect of daily life, say the authors.

"These positive effects of physical exercise on inhibition/interference control are encouraging and highly relevant, given the importance of inhibitory control and interference control in daily life," they write.

"Inhibition is essential for regulation of behaviour and emotions in social, academic, and sport settings," they add.

They speculate that short bouts of exercise may boost the cerebral blood flow to the pre-frontal areas of the brain, responsible for higher (executive) functions.

Exercise might be a useful treatment for conditions characterised by impaired higher brain functions, such as attention hyperactivity deficit disorder (ADHD) and autism, and may help delay the ravages of dementia, they suggest.

"Given the trend for a more sedentary lifestyle, worldwide ageing and the increasing prevalence of dementia, the results highlight the importance of engaging in physical exercise in the general population," they conclude.

Wednesday, March 6, 2013

A stimulating environment may protect against Alzheimer's Disease


"Use it or lose it." The saying could apply especially to the brain when it comes to protecting against Alzheimer's disease. Previous studies have shown that keeping the mind active, exercising and social interactions may help delay the onset of dementia in Alzheimer's disease.

Now, a new study led by Dennis Selkoe, MD, co-director of the Center for Neurologic Diseases in the BWH Department of Neurology, provides specific pre-clinical scientific evidence supporting the concept that prolonged and intensive stimulation by an enriched environment, especially regular exposure to new activities, may have beneficial effects in delaying one of the key negative factors in Alzheimer's disease.

The study will be published online on March 6, 2013 in Neuron.

Alzheimer's disease occurs when a protein called amyloid beta accumulates and forms "senile plaques" in the brain. This protein accumulation can block nerve cells in the brain from properly communicating with one another. This may gradually lead to an erosion of a person's mental processes, such as memory, attention, and the ability to learn, understand and process information.

The BWH researchers used a wild-type mouse model when evaluating how the environment might affect Alzheimer's disease. Unlike other pre-clinical models used in Alzheimer's disease research, wild-type mice tend to more closely mimic the scenario of average humans developing the disease under normal environmental conditions, rather than being strongly genetically pre-disposed to the disease.

Selkoe and his team found that prolonged exposure to an enriched environment activated certain adrenalin-related brain receptors which triggered a signaling pathway that prevented amyloid beta protein from weakening the communication between nerve cells in the brain's "memory center," the hippocampus. The hippocampus plays an important role in both short- and long-term memory.

The ability of an enriched, novel environment to prevent amyloid beta protein from affecting the signaling strength and communication between nerve cells was seen in both young and middle-aged wild-type mice.

"This part of our work suggests that prolonged exposure to a richer, more novel environment beginning even in middle age might help protect the hippocampus from the bad effects of amyloid beta, which builds up to toxic levels in one hundred percent of Alzheimer patients," said Selkoe.

Moreover, the scientists found that exposing the brain to novel activities in particular provided greater protection against Alzheimer's disease than did just aerobic exercise. According to the researchers, this observation may be due to stimulation that occurred not only physically, but also mentally, when the mice moved quickly from one novel object to another.

"This work helps provide a molecular mechanism for why a richer environment can help lessen the memory-eroding effects of the build-up of amyloid beta protein with age," said Selkoe. "They point to basic scientific reasons for the apparent lessening of AD risk in people with cognitively richer and more complex experiences during life."

Excess dietary salt may drive the development of autoimmune diseases



Increased dietary salt intake can induce a group of aggressive immune cells that are involved in triggering and sustaining autoimmune diseases. In autoimmune diseases, the immune system attacks healthy tissue instead of fighting pathogens.

In recent decades scientists have observed a steady rise in the incidence of autoimmune diseases in the Western world. Since this increase cannot be explained solely by genetic factors, researchers hypothesize that the sharp increase in these diseases is linked to environmental factors. Among the suspected culprits are changes in lifestyle and dietary habits in developed countries, where highly processed food and fast food are often on the daily menu. These foods tend to have substantially higher salt content than home-cooked meals. This study is the first to indicate that excess salt intake may be one of the environmental factors driving the increased incidence of autoimmune diseases.

A few years ago Jens Titze showed that excess dietary salt (sodium chloride) accumulates in tissue and can affect macrophages (a type of scavenger cells) of the immune system. Independent of this study, Markus Kleinewietfeld and David Hafler observed changes in CD4 positive T helper cells (Th) in humans, which were associated with specific dietary habits. The question arose whether salt might drive these changes and thus can also have an impact on other immune cells. Helper T cells are alerted of imminent danger by the cytokines of other cells of the immune system. They activate and "help" other effector cells to fight dangerous pathogens and to clear infections. A specific subset of T helper cells produces the cytokine interleukin 17 and is therefore called Th17 for short. Evidence is mounting that Th17 cells, apart from fighting infections, play a pivotal role in the pathogenesis of autoimmune diseases.

Salt dramatically boosts the induction of aggressive Th17 immune cells

In cell culture experiments the researchers showed that increased sodium chloride can lead to a dramatic induction of Th17 cells in a specific cytokine milieu. "In the presence of elevated salt concentrations this increase can be ten times higher than under usual conditions," Markus Kleinewietfeld and Dominik Müller explained. Under the new high salt conditions, the cells undergo further changes in their cytokine profile, resulting in particularly aggressive Th17 cells.

In mice, increased dietary salt intake resulted in a more severe form of experimental autoimmune encephalomyelitis, a model for multiple sclerosis. Multiple sclerosis is an autoimmune disease of the central nervous system in which the body's own immune system destroys the insulating myelin sheath around the axons of neurons and thus prevents the transduction of signals, which can lead to a variety of neurological deficits and permanent disability. Recently, researchers postulated that autoreactive Th17 cells play a pivotal role in the pathogenesis of multiple sclerosis.

Interestingly, according to the researchers, the number of pro-inflammatory Th17 cells in the nervous system of the mice increased dramatically under a high salt diet. The researchers showed that the high salt diet accelerated the development of helper T cells into pathogenic Th17 cells. The researchers also conducted a closer examination of these effects in cell culture experiments and showed that the increased induction of aggressive Th17 cells is regulated by salt on the molecular level. "These findings are an important contribution to the understanding of multiple sclerosis and may offer new targets for a better treatment of the disease, for which at present there is no known cure," said Ralf Linker, who as head of the Neuroimmunology Section and Attending Physician at the Department of Neurology, University Hospital Erlangen, seeks to utilize new laboratory findings for the benefit of patients.

Besides multiple sclerosis, Dominik Müller and his colleagues want to study psoriasis, another autoimmune disease with strong Th17 components. The skin, as Jens Titze recently discovered, also plays a key role in salt storage and affects the immune system. "It would be interesting to find out if patients with psoriasis can alleviate their symptoms by reducing their salt intake," the researchers said. "However, the development of autoimmune diseases is a very complex process which depends on many genetic and environmental factors," the immunologist Markus Kleinewietfeld said. "Therefore, only further studies under less extreme conditions can show the extent to which increased salt intake actually contributes to the development of autoimmune diseases."

Tuesday, March 5, 2013

Exercise Key to Good Sleep

Exercise can affect your sleep. The results of the National Sleep Foundation’s 2013 Sleep in America® poll show a compelling association between exercise and better sleep. 

“Exercise is great for sleep. For the millions of people who want better sleep, exercise may help,” says David Cloud, CEO of the National Sleep Foundation (NSF). 

Exercisers say they sleep better
Self-described exercisers report better sleep than self-described non-exercisers even though they say they sleep the same amount each night (6 hours and 51 minutes, average on weeknights). Vigorous, moderate and light*exercisers are significantly more likely to say “I had a good night’s sleep” every night or almost every night on work nights than non-exercisers (67%-56% vs. 39%). Also, more than three-fourths of exercisers (76%-83%) say their sleep quality was very good or fairly good in the past two weeks, compared to slightly more than one-half of non-exercisers (56%).

“If you are inactive, adding a 10 minute walk every day could improve your likelihood of a good night’s sleep,” says Max Hirshkowitz, PhD, poll task force chair. “Making this small change and gradually working your way up to more intense activities like running or swimming could help you sleep better.”

“Our poll data certainly find strong relationships between good sleep and exercise,” adds Hirshkowitz. “While cause and effect can be tricky, I don’t think having good sleep necessarily compels us to exercise. I think it is much more likely that exercising improves sleep. And good sleep is fundamental for good health, productivity, and happiness.” 

Vigorous exercisers report the best sleep
Vigorous exercisers are almost twice as likely as non-exercisers to report “I had a good night’s sleep” every night or almost every night during the week. They also are the least likely to report sleep problems. More than two-thirds of vigorous exercisers say they rarely or never (in the past 2 weeks) had symptoms commonly associated with insomnia, including waking up too early and not being able to get back to sleep (72%) and difficulty falling asleep (69%). In contrast, one-half (50%) of non-exercisers say they woke up during the night and nearly one-fourth (24%) had difficulty falling asleep every night or almost every night.

“Poor sleep might lead to negative health partly because it makes people less inclined to exercise,” says Shawn Youngstedt, PhD, poll task force member. “More than one half (57%) of the total sample reported that their activity level will be less than usual after a night of poor sleep. Not exercising and not sleeping becomes a vicious cycle.”

Non-exercisers are the sleepiest and have the highest risk for sleep apnea
Non-exercisers tend toward being more excessively sleepy than exercisers. Nearly one-fourth of non-exercisers (24%) qualify as “sleepy” using a standard excessive sleepiness clinical screening measure. This sleepiness level occurs about twice as often than for exercisers (12-15%). Also, about six in ten of non-exercisers (61%) say they rarely or never have a good night’s sleep on work nights. 

Sleepiness clearly interferes with many non-exercisers’ safety and quality of life. One in seven non-exercisers (14%) report having trouble staying awake while driving, eating or engaging in social activity at least once a week in the past two weeks, almost three times the rate of those who exercise (4-6%).

“Sometimes we might feel tired, and that's normal,” says Matthew Buman, PhD, poll task force member, “but if excessive sleepiness is your normal state, it warrants a conversation with your doctor. It could be a red flag that something is wrong with your health.”

Indeed, non-exercisers have more symptoms of sleep apnea. Sleep apnea is a serious medical condition in which a person stops breathing during sleep. Its symptoms often include tiredness, snoring, and high blood pressure. It also increases the risk for heart disease and stroke. More than four in ten non-exercisers (44%) exhibit a moderate risk of sleep apnea, compared to between one in four and one in five of light exercisers (26%), moderate exercisers (22%) and vigorous exercisers (19%). 

“The poll data suggest that the risk of sleep apnea in exercisers is half that of non-exercisers,” says Christopher Kline, PhD, poll task force member. “People with sleep apnea are often overweight. Exercise can be part of the treatment.”

Less time sitting is associated with better sleep and health
Separate from exercise, spending less time sitting may improve sleep quality and health. Those who sit for less than eight hours per day sitting are significantly more likely to say they have “very good” sleep quality than those who sit for eight hours or more (22%-25% compared to 12%-15%). Furthermore, significantly more of those who spend less than 10 hours per day sitting mention excellent health, compared to those who spend 10 hours or more sitting (25-30% compared to 16%). 

“This poll is the first to show that simply spending too much time sitting might negatively affect our sleep quality,” says Prof. Marco Tulio de Mello, poll task force member. “In addition to exercise, standing at your desk, getting up for short breaks, and moving around as much as possible are important healthy behaviors to include in our lives.”

Exercise at any time of day appears to be good for sleep
Those who report exercising close to bedtime and earlier in the day do not demonstrate a difference in self-reported sleep quality. In fact, for most people exercise at any time seems to be better for sleep than no exercise at all. 

This finding contradicts long-standing “sleep hygiene” tips that advise everyone not to exercise close to bedtime. The National Sleep Foundation has amended its sleep recommendations for “normal” sleepers to encourage exercise without any caveat to time of day as long as it’s not at the expense of sleep. (However, people with chronic insomnia should continue to restrict late evening and night exercise, if this is part of their treatment regimen.) 

“Exercise is beneficial to sleep. It's time to revise global recommendations for improving sleep and put exercise—any time—at the top of our list for healthy sleep habits,” says Dr. Barbara Phillips, poll task force member. 

Healthy Sleep Advice
To improve your sleep, try the following sleep tips:

  • Exercise regularly. Vigorous exercise is best, but even light exercise is better than no activity. Exercise at any time of day, but not at the expense of your sleep.
  • Create an environment that is conducive to sleep that is quiet, dark and cool with a comfortable mattress and pillows.
  • Practice a relaxing bedtime ritual, like a warm bath or listening to calming music.
  • Go to sleep and wake at the same time every day, and avoid spending more time in bed than needed.
  • Use bright light to help manage your "body clock." Avoid bright light in the evening and expose yourself to sunlight in the morning.
  • Use your bedroom only for sleep to strengthen the association between your bed and sleep. It may help to remove work materials, computers and televisions from your bedroom.
  • Save your worries for the daytime. If concerns come to mind, write them in a "worry book" so you can address those issues the next day.
  • If you can't sleep, go into another room and do something relaxing until you feel tired.
  • If you are experiencing excessive daytime sleepiness, snoring, or “stop breathing” episodes in your sleep, contact your health care professional for a sleep apnea screening.

Poll Methodology and Definitions
The 2013 Sleep in America® annual poll was conducted for the National Sleep Foundation by WB&A Market Research, using a sample of 1,000 adults between the ages of 23 and 60. The number of completes needed for both age groups and regions was determined using the most current U.S. Census data from 2010.

The maximum sampling error of the data for the total sample is +/- 3.1 percentage points at the 95% confidence level. The sampling error will vary depending on the sample size and the percentages being examined in the sample.

* Using a self-reported measure of physical activity, for which respondents considered physical activity they did for at least 10 minutes in the past 7 days, participants were classified into four different activity levels:  vigorous, moderate, light and no activity.  In this self-report measure, vigorous was defined as activities which require hard physical effort such as:  running, cycling, swimming or competitive sports.  The next level, moderate, was defined as activities which require more effort than normal such as:  yoga, tai chi and weight lifting.  Light activity was defined as walking, while those who do not do any activity classified themselves into the no activity level.  Segments are often referred to as vigorous exercisers, moderate exercisers, light exercisers and non-exercisers based on this measure of self-categorization.

Why fish is so good for you



Jena (Germany) Fish is healthy: easy to digest and with a high level of precious proteins, fish is considered an important part of a healthy diet. And with the so-called omega-3 fatty acids fish contains real 'fountains of youth'. These fatty acids – like docosahexaeonic acid (DHA) occur mostly in fatty fish like herring, salmon and mackerel. They are thought to lower the blood pressure, to strengthen the immune system and to have positive effects on the development on the nervous system and the cardiovascular system.

"Clinical studies about the intake of nutritional supplements containing omega-3 fatty acids haven't provided complete clarity so far," Prof. Dr. Stefan H. Heinemann from Friedrich Schiller University Jena (Germany) says. "The molecular impact of the omega-3 fatty acids isn't fully understood yet," the biophysicist continues. But now scientists of the DFG research group FOR 1738 based at Jena University are able to bring new facts to light: in two newly published articles for the well-known science magazine 'Proceedings of the National Academy of Sciences, USA' they describe how they analyzed the impact of omega-3 fatty acids on a systemic level and they also described the underlying molecular mechanisms for the first time.

The teams around Prof. Heinemann (Jena University), Prof. Dr. Michael Bauer (Jena University Hospital) and Prof. Dr. Toshinori Hoshi (University of Pennsylvania) were able to show that the so-called 'SLO1' potassium channel is an important component in the effectiveness of omega-3 fatty acids. "These ionic channels act like very specific receptors for DHA and are opened by the binding of the omega-3 fatty acids," Biophysicist Heinemann explains. In the case of other omega-3 fatty acids – like the shorter eicosapentaenoic acid (EPA) or the alpha-linolenic acid (ALA) extracted from plants – the impact is much weaker.

Prof. Bauer and his colleagues examined the effects of omega-3 fatty acids on SLO1 channels of the cardiovascular system by experimenting with mice. "Administration of DHA should result in an expansion of the blood vessels and consequently a drop in blood pressure," the physician says. The laboratory experiments confirmed exactly that. In genetically modified mice however, which were not able to produce the SLO1 channel, the antihypertensive impact of DHA failed to appear. "Thus we were able to show for the first time that DHA directly influences the blood pressure, which is being mediated through SLO1 channels," Bauer summarizes.

Beyond that, the scientists made another surprising discovery: a variant of DHA, which can often be found in nutritional supplements containing omega-3 fatty acids, doesn't show an antihypertensive effect. Moreover, it suppresses and even diminishes the effect of the natural DHA from fish oil. "The intake of non-natural omega-3 fatty acids can therefore also have counter-productive effects," Prof. Bauer stresses. This is of particular importance for the nutritional supplements of patients in intensive care who are being drip-fed: their supplements of omega-3 fatty acids should be specifically aimed at and adapted to the patients' clinical requirements.

Walking Away from Back Pain



Home aerobic program as effective as clinical therapy in treating lower back pain, finds TAU researcher

Lower back pain is a common complaint, and treatment often requires many hours of physical therapy over multiple weekly clinic visits — a costly commitment. Now Dr. Michal Katz-Leurer of Tel Aviv University's Stanley Steyer School of Health Professions at the Sackler Faculty of Medicine says that a simple aerobic walking program is as effective in alleviating lower back pain as muscle strengthening programs that require specialized equipment in rehabilitation clinics. The program includes walking two to three times a week for a period of 20 to 40 minutes.

Dr. Katz-Leurer and her colleague Ilana Shnayderman, a graduate student at the Department of Physical Therapy and a practicing physiotherapist at Maccabi Health Care, say that their treatment option fits easily into a daily routine and allows those with back pain to be more responsible for their own health.

Their study was published in the journal Clinical Rehabilitation.

According to Dr. Katz-Leurer, research has shown that when people walk actively, abdominal and back muscles work in much the same way as when they complete exercises that target these areas. And unlike muscle strengthening programs, which often call for specific equipment and can involve exercises that require expert supervision, walking is a simple activity that can be done alone.

For the study, the researchers recruited 52 patients with lower back pain to participate in a randomized control trial. Through questionnaires, they were initially assessed for pain levels, feelings of disability, and avoidance of daily activities, as well as muscle and walking endurance.

Then, half of the participants completed a typical clinic-based muscle strengthening program, with two to three exercise sessions a week for six weeks. The other half completed a six-week aerobic walking program, walking two to three times weekly. Participants started with 20 minutes of walking, then progressed to 40 minutes as their endurance improved.

Results showed that both groups improved significantly in all areas of assessment, demonstrating that the walking program was "as effective as treatment that could have been received in the clinic," says Dr. Katz-Leurer.

The path to a healthier lifestyle

Dr. Katz-Leurer says that the walking program has the additional advantage of encouraging patients to follow a healthier lifestyle overall. In terms of physical fitness, those in the walking group were able to walk an average of 0.05 miles farther during a six-minute walking test at the end of the program compared to the pre-program assessments.

She also notes that that regularly active people are less likely to suffer typical aches and pains over their lifetime. Walking, a low-impact activity, also lowers blood pressure, boosts brain and immune system functioning, and reduces stress, she says.

The Importance Of Eating Your Greens



Eating your greens may be even more important that previously thought, with the discovery that an immune cell population essential for intestinal health could be controlled by leafy greens in your diet.

The immune cells, named innate lymphoid cells (ILCs), are found in the lining of the digestive system and protect the body from 'bad' bacteria in the intestine. They are also believed to play an important role in controlling food allergies, inflammatory diseases and obesity, and may even prevent the development of bowel cancers.

Dr Gabrielle Belz, Ms Lucie Rankin, Dr Joanna Groom and colleagues from the Walter and Eliza Hall Institute's Molecular Immunology division have discovered the gene T-bet is essential for producing a population of these critical immune cells and that the gene responds to signals in the food we eat.

Dr Belz said the research team revealed T-bet was essential for generating a subset of ILCs which is a newly discovered cell type that protects the body against infections entering through the digestive system. "In this study, we discovered that T-bet is the key gene that instructs precursor cells to develop into ILCs, which it does in response to signals in the food we eat and to bacteria in the gut," Dr Belz said. "ILCs are essential for immune surveillance of the digestive system and this is the first time that we have identified a gene responsible for the production of ILCs."

The research was published in the journal Nature Immunology.

Dr Belz said that the proteins in green leafy (cruciferous) vegetables are known to interact with a cell surface receptor that switches on T-bet, and might play a role in producing these critical immune cells. "Proteins in these leafy greens could be part of the same signalling pathway that is used by T-bet to produce ILCs," Dr Belz said. "We are very interested in looking at how the products of these vegetables are able to talk to T-bet to make ILCs, which will give us more insight into how the food we eat influences our immune system and gut bacteria."

ILCs are essential for maintaining the delicate balance between tolerance, immunity and inflammation. Ms Rankin said the discovery had given the research team further insight into external factors responsible for ILC activation. "Until recently, it has been difficult to isolate or produce ILCs," Ms Rankin said. "So we are very excited about the prospect for future research on these cells which are still poorly understood."

ILCs produce a hormone called interleukin-22 (IL-22), which can protect the body from invading bacteria, Dr Belz said. "Our research shows that, without the gene T-bet, the body is more susceptible to bacterial infections that enter through the digestive system. This suggests that boosting ILCs in the gut may aid in the treatment of these bacterial infections," she said.

ILCs help to maintain a 'healthy' environment in the intestine by promoting good bacteria and healing small wounds and abrasions that are common in the tissues of the gut. They may also have a role in resolving cancerous lesions. "The discovery of these immune cells has thrown open a completely new way of looking at gut biology," Dr Belz said. "We are just starting to understand how important these immune cells are in regulating allergy and inflammation, and the implications for bowel cancer and other gastrointestinal disorders such as Crohn's disease," she said.

"Understanding the biology of ILCs and the genes that are essential for generating them will help us to develop methods of targeting these cells," Dr Belz said. "This might include boosting ILCs in situations where they may not be active enough, such as infections or some cancers, or depleting them in situations where they are overactive, such as chronic inflammatory disease," she said.

Colonoscopy Reduces Advanced Cancer Risk by 70 Percent


A new study finds that getting screening colonoscopies may reduce the risk of developing advanced colon cancer.

In average-risk people, screening colonoscopies were associated with a 70 percent reduction in risk for new, late-stage colon cancer, including hard-to-detect cancers on the right side of the colon. Advanced colon cancer is the least curable form.

Although colonoscopy is widely used as a screening test for colon cancer, there is little research that proves it is effective in reducing colon cancer deaths, according to the study authors. The researchers wanted to answer a simple question: If you ended up with late-stage cancer, were you more or less likely to have had a screening colonoscopy as many as 10 years before the disease was discovered?

The study authors also wanted to show whether a colonoscopy is able to evaluate the entire colon, including the right side, which is harder to adequately cleanse before the test, more difficult to reach, and often has pre-cancerous areas that are tougher to spot and identify.

"Colonoscopy has the ability to identify both left- and right-sided colon cancers before they have progressed to an advanced stage," said lead study author Dr. Chyke Doubeni, associate professor in the department of family medicine at the University of Pennsylvania.

The researchers also discovered that screening sigmoidoscopy, a less costly procedure that enables a physician to look at the part of the large intestine closest to the rectum, was linked to a significant reduction in late-stage disease in most of the large intestine, but not in the right colon.

However, the study does not show that colonoscopy or sigmoidoscopy is better than the much easier, far less expensive "fecal occult blood test" (FOBT), which is done at home by swiping a tiny amount of stool onto a card for three days, said Doubeni. "There is strong evidence showing the effectiveness of the [fecal occult blood test] when done annually. There is no reason, based on the knowledge we currently have, that you should switch to a colonoscopy if you're getting a FOBT every year," said Doubeni.

If simpler tests are effective, why are patients encouraged to undergo a colonoscopy? "Let me just say there are other factors beyond the evidence that are driving the use of colonoscopy in the U.S.," said Doubeni. "No other country uses colonoscopy for screening purposes as much as the United States, although Germany comes close," he noted.

The U.S. Preventive Services Task Force recommends that people 50 to 75 years old be screened for colon cancer in one of three ways: a home fecal occult blood test every year; a sigmoidoscopy every five years combined with a home fecal occult blood test every three years; or a colonoscopy every 10 years.

A colonoscopy examines the inside of the large intestine with a camera-tipped tube. The test enables the physician to remove any precancerous growths -- adenomatous polyps -- which sometimes develop into cancer. Colorectal tumors are a major cause of death from cancer in the United States, with about 137,000 new cases and 52,000 deaths every year, according to the U.S. Centers for Disease Control and Prevention.

For the study, published in the March 5 issue of the Annals of Internal Medicine, the authors reviewed health records of more than 1,000 average-risk adults between the ages of 55 and 85 who were members in four health management organizations (HMOs).

The researchers identified 474 people with late-stage colon cancer and then looked back 10 years to see if they had been screened for the disease with colonoscopy or sigmoidoscopy. They compared them to 538 "control" patients and used additional information from state or local tumor registries to see whether there was an association between having had a colonoscopy or sigmoidoscopy and developing cancer.

Dr. David Bernstein, a gastroenterologist at North Shore University Hospital in Manhasset, N.Y., said the study had a critical design flaw. "Making assumptions that any cancers that were found would have been seen 10 years prior doesn't make sense," he said. "It doesn't prove that these cancers didn't occur two years ago."

A key part of effective colon screening is getting the tests at the recommended interval, experts say. To better understand what might be effective in prodding people to get screening, another study published this month in the same journal found that people who were mailed a letter, a pamphlet and a fecal occult blood test kit completed recommended screening twice as often and for less cost than those who were not reminded or got automated and other reminders by nurse coaches.

Doubeni recommends something far more simple: doing the fecal occult blood test every year right around the time of your birthday.

Monday, March 4, 2013

Physical Activity and Health


by Gregory J. Colman, Dhaval M. Dave - #18858 (HE)

Abstract:

While the link between physical activity and health has been studied,
there are several limitations that persist in this literature
relating to external and internal validity of the estimates,
potential measurement error in self-reported weight and risk factors,
failure to account for physical activity beyond exercise, and failure
to separate the effects of exercise from other forms of physical
activity. This study addresses these gaps and assesses plausibly
causal effects of recreational exercise and other physical activity
(including work-related activity) on the risk factors for heart
disease, utilizing a population-based longitudinal dataset that
contains objective information on key risk factors.

There are four key patterns of results that emerge:

First, the lagged effect of physical activity is almost
always larger than the current effect. This suggests that current
risk factors, not only obesity but also high blood pressure and heart
rate, take years to develop, which underscores the importance of
consistent physical activity to ward off heart disease.

Second, in general physical activity reduces risk factors for heart
disease even after controlling, to some extent, for unobservable
confounding influences.

Third, not only recreational but work-related physical activity
appears to protect against heart disease.

Finally, there is evidence of a dose-response relationship
such that higher levels of recreational exercise and other physical
activity have a greater protective effect.

Declines in high levels of recreational exercise and other physical
activity can potentially account for between 12-30% of the increase
in obesity, hypertension, diabetes, and heart disease observed over
the sample period.

Friday, March 1, 2013

Contaminated diet contributes to phthalate and bisphenol A exposure



Even organic foods not stored, prepared or cooked in plastic containers can contain these contaminants


While water bottles may tout BPA-free labels and personal care products declare phthalates not among their ingredients, these assurances may not be enough. According to a study published February 27 in the Nature Journal of Exposure Science and Environmental Epidemiology, people may be exposed to these chemicals in their diets, even if their meals are organic and foods are prepared, cooked and stored in non-plastic containers. And children may be most vulnerable.

"Current information we give families may not be enough to reduce exposures," said Dr. Sheela Sathyanarayana, lead author on the study and an environmental health pediatrician in the University of Washington School of Public Health and at Seattle Children's Research Institute. She is an assistant professor of pediatrics at the UW School of Medicine and an attending physician at Harborview Medical Center's Pediatric Environmental Health Specialty Unit.

Phthalates and bisphenol A (BPA) are synthetic endocrine-disrupting chemicals. Previous studies have linked prenatal exposure to phthalates to abnormalities in the male reproductive system. Associations have also been shown between fetal exposure to BPA and hyperactivity, anxiety, and depression in girls.

The researchers compared the chemical exposures of 10 families, half who were given written instructions on how to reduce phthalate and BPA exposures, handouts developed by the national Pediatric Environmental Health Specialty Units, a network of experts on environmentally related health effects in children. For five days the other families received a local, fresh, organic food catered diet that was not prepared, cooked or stored in plastic containers

When the researchers tested the urinary concentrations of metabolites for phthalates and BPA, they got surprising results. The researchers expected the levels of the metabolities to decrease in those adults and children eating the catered diet.

Instead, the opposite happened. The urinary concentration for pthalates were 100-fold higher than the those levels found in the majority of the general population, The comparison comes from a study conducted by the National Health and Nutrition Examination Survey (NHANES), a program of studies managed by the Centers for Disease Control and Prevention and designed to assess the health and nutritional status of adults and children in the United States. The concentrations were also much higher for children as compared to the adults.

Then, the researchers tested the phthalate concentrations in the food ingredients used in the dietary intervention. Dairy products—butter, cream, milk, and cheese—had concentrations above 440 nanograms/gram. Ground cinnamon and cayenne pepper had concentrations above 700 ng/g, and ground coriander had concentrations of 21,400 ng/g.

"We were extremely surprised to see these results. We expected the concentrations to decrease significantly for the kids and parents in the catered diet group. Chemical contamination of foods can lead to concentrations higher than deemed safe by the U.S. Environmental Protection Agency," said Sathyanarayana.

Using the study results, the researchers estimated that the average child aged three to six years old was exposed to 183 milligrams per kilogram of their body weight per day. The U.S. Environmental Protection Agency's recommended limit is 20 mg/kg/day.

"It's difficult to control your exposure to these chemicals, even when you try," said Sathyanarayana. "We have very little control over what's in our food, including contaminants. Families can focus on buying fresh fruits and vegetables, foods that are not canned and are low in fat, but it may take new federal regulations to reduce exposures to these chemicals."