Thursday, January 29, 2015

Heavy drinking in middle-age may increase stroke risk more than traditional factors


Drinking more than two alcoholic beverages daily in middle-age may raise your stroke risk more than traditional factors such as high blood pressure and diabetes, according to new research in the American Heart Association journal Stroke.

In a study of 11,644 middle-aged Swedish twins who were followed for 43 years, researchers compared the effects of an average of more than two drinks daily ("heavy drinking") to less than half a drink daily ("light drinking").

The study showed that:

Heavy drinkers had about a 34 percent higher risk of stroke compared to light drinkers.
Mid-life heavy drinkers (in their 50s and 60s) were likely to have a stroke five years earlier in life irrespective of genetic and early-life factors.
Heavy drinkers had increased stroke risk in their mid-life compared to well-known risk factors like high blood pressure and diabetes.
At around age 75, blood pressure and diabetes appeared to take over as one of the main influences on having a stroke.
Past studies have shown that alcohol affects stroke risk, but this is the first study to pinpoint differences with age.

"We now have a clearer picture about these risk factors, how they change with age and how the influence of drinking alcohol shifts as we get older," said Pavla Kadlecová, M.Sc., a statistician at St. Anne's University Hospital's International Clinical Research Center in the Czech Republic.

Researchers analyzed results from the Swedish Twin Registry of same-sex twins who answered questionnaires in 1967-70. All twins were under age 60 at the start. By 2010, the registry yielded 43 years of follow-up, including hospital discharge and cause of death data.

Researchers then sorted the data based on stroke, high blood pressure, diabetes and other cardiovascular incidences.

Almost 30 percent of participants had a stroke. They were categorized as light, moderate, heavy or non-drinkers based on the questionnaires. Researchers compared the risk from alcohol and health risks like high blood pressure, diabetes and smoking.

Among identical twin pairs, siblings who had a stroke drank more than their siblings who hadn't had a stroke, suggesting that mid-life drinking raises stroke risks regardless of genetics and early lifestyle.

The study is consistent with the American Heart Association's recommended limit of two drinks a day for men and one for women. That's about 8 ounces of wine (two drinks) for a man and 4 ounces (one drink) for a woman.

Regular heavy drinking of any kind of alcohol can raise blood pressure and cause heart failure or irregular heartbeats over time with repeated drinking, in addition to stroke and other risks.

"For mid-aged adults, avoiding more than two drinks a day could be a way to prevent stroke in later productive age (about 60s)," Kadlecová said.


Oatmeal for breakfast results in greater fullness and lower calorie intake at lunch


A new study suggests that your breakfast cereal choice may affect how full you feel and how much you eat for lunch, especially if you're overweight. According to new research published in the latest issue of the Annals of Nutrition and Metabolism, scientists found that having oatmeal (Quaker Oats Quick 1-minute™) for breakfast resulted in greater fullness, lower hunger ratings and fewer calories eaten at the next meal compared to a calorie-matched breakfast of a ready-to-eat cereal (RTEC) - sugared corn flakes.

Scientists from the New York Obesity Nutrition Research Center at Mount Sinai St. Luke's Hospital randomly assigned 36 subjects (18 normal weight and 18 overweight) to each receive three different breakfasts. The breakfasts consisted of 350 calories of similar amounts of carbohydrates, fat and liquid from either quick-cook oatmeal or sugared corn flakes. A third control breakfast was only 1.5 cups of water. To evaluate appetite, ratings of hunger and fullness were obtained at frequent intervals before and after the breakfast until a lunch test meal 3 hours later. Researchers measured the calorie intake of the lunch meal consumed to compare the effects of the corn flakes, oatmeal or water breakfasts. Blood samples were collected just after each of the appetite ratings to assess levels of glucose, insulin, acetaminophen (a marker for how quickly the breakfast emptied from the stomach into the intestine) and various hormones related to appetite, in response to each breakfast.

"Our results show that despite eating the same number of calories at breakfast, satiety values were significantly greater after consuming oatmeal compared to sugared corn flakes. After three hours, subjects reported the same level of hunger after having a corn flakes breakfast as they did when they consumed only water," explained lead researcher Allan Geliebter, PhD, research psychologist in the Department of Psychiatry at Mount Sinai St. Luke's Hospital. "Interestingly, the results were more pronounced for the participants who were overweight, suggesting that overweight individuals may be more responsive to the satiety effects of the dietary fiber in oatmeal."

The results showed statistically significant higher ratings of fullness, lower ratings of hunger, and 31% fewer calories consumed at lunch after consuming oatmeal compared to sugared corn flakes or water. The overall satiety effect was greater among overweight subjects, who consumed 50% fewer calories at lunch after eating oatmeal.

The study authors suggested that the greater satiety effect of oatmeal cereal compared to sugared corn flakes or water might be due to a slower gastric emptying (oatmeal took longer to leave the stomach). Given that the results were more pronounced in overweight subjects, researchers suggested that a longer-term weight control study testing daily oatmeal for breakfast is warranted.

"Consumers choose oatmeal for its great taste, well-established health benefits and convenience, but scientists are finding that eating oatmeal for breakfast may also be one of the easiest ways to improve satiety after breakfast," adds Marianne O'Shea, PhD, Director, Quaker Oats Center of Excellence. "We are encouraged by the potential for future investigations that could have a positive impact on public health and give people more reasons to enjoy oat-based breakfasts and snacks."


Poor psychosocial work environments may contribute to heart problems


A psychosocially poor work environment means that employees experience highly demanding requirements but have little ability to control their work or not feel sufficiently appreciated for the contributions they make.

Related to work situation

A dissertation at The Sahlgrenska Academy, Gothenburg University, shows that men who have recently suffered a heart attack or angina and who feel that they have a poor psychosocial work environment see a relationship between their heart disease and their work situation.

These men often believe that it would take longer for them before they could return to work, says Mia Söderberg, the doctoral candidate who wrote the dissertation.

Warning signs

Men who do not have heart problems but who experience poor psychosocial work conditions often have warning signs for coronary artery disease, such as high blood pressure and high cholesterol values. Mia Söderberg can also draw the conclusion that these men more often change jobs, and points out here a difference between women and men.

We could only see this connection with men, which may depend upon the labor market being segregated by gender and on woman and men generally working within different work categories where the capacity to influence ones work environment differs, Mia Söderberg says, and continues:

For women the combination of job-related stress and household work may also have a greater influence on health and various health-related behavior than it has with men.

New focus on psychosocial factors

The labor market is no longer dominated by industry, but work instead deals more and more with knowledge processes and contact with other people.

In work-related illness, we have also seen a shift from a focus on physical risk factors to a greater need to examine psychosocial factors, Mia Söderberg says.

The dissertation is based upon answers from 509 persons in Western Götaland with acute coronary symptoms, which encompasses all conditions in which arterial calcification has suddenly caused the heart not to have enough blood. 2492 randomly chosen residents of Greater Gothenburg and 75,236 male Swedish construction workers also answered surveys.

Higher dementia risk linked to more use of common drugs



Dr. Shelly Gray et. al. found a persistent link in a University of Washington/Group Health study published in JAMA Internal Medicine on January 26, 2015. The large study links a significantly increased risk for developing dementia, including Alzheimer’s disease, to taking commonly used medications with anticholinergic effects at higher doses or for a longer time. Many older people take these medications, which include nonprescription diphenhydramine (Benadryl). JAMA Internal Medicine published the report, called “Cumulative Use of Strong Anticholinergic Medications and Incident Dementia.”

The study used more rigorous methods, longer follow-up (more than seven years), and better assessment of medication use via pharmacy records (including substantial nonprescription use) to confirm this previously reported link. It is the first study to show a dose response: linking more risk for developing dementia to higher use of anticholinergic medications. And it is also the first to suggest that dementia risk linked to anticholinergic medications may persist—and may not be reversible even years after people stop taking these drugs.

“Older adults should be aware that many medications—including some available without a prescription, such as over-the-counter sleep aids—have strong anticholinergic effects,” said Shelly Gray, PharmD, MS, the first author of the report, which tracks nearly 3,500 Group Health seniors participating in the long-running Adult Changes in Thought (ACT), a joint Group Health–University of Washington (UW) study funded by the National Institute on Aging. “And they should tell their health care providers about all their over-the-counter use,” she added.

“But of course, no one should stop taking any therapy without consulting their health care provider,” said Dr. Gray, who is a professor, the vice chair of curriculum and instruction, and director of the geriatric pharmacy program at the UW School of Pharmacy. “Health care providers should regularly review their older patients’ drug regimens—including over-the-counter medications—to look for chances to use fewer anticholinergic medications at lower doses.”

For instance, the most commonly used medications in the study were tricyclic antidepressants like doxepin (Sinequan), first-generation antihistamines like chlorpheniramine (Chlor-Trimeton), and antimuscarinics for bladder control like oxybutynin (Ditropan). The study estimated that people taking at least 10 mg/day of doxepin, 4 mg/day of chlorpheniramine, or 5 mg/day of oxybutynin for more than three years would be at greater risk for developing dementia. Dr. Gray said substitutes are available for the first two: a selective serotonin re-uptake inhibitor (SSRI) like citalopram (Celexa) or fluoxitene (Prozac) for depression and a second-generation antihistamine like loratadine (Claritin) for allergies. It’s harder to find alternative medications for urinary incontinence, but some behavioral changes can reduce this problem.

“If providers need to prescribe a medication with anticholinergic effects because it is the best therapy for their patient,” Dr. Gray said, “they should use the lowest effective dose, monitor the therapy regularly to ensure it’s working, and stop the therapy if it’s ineffective.” Anticholinergic effects happen because some medications block the neurotransmitter called acetylcholine in the brain and body, she explained. That can cause many side effects, including drowsiness, constipation, retaining urine, and dry mouth and eyes.

“With detailed information on thousands of patients for many years, the ACT study is a living laboratory for exploring risk factors for conditions like dementia,” said Dr. Gray’s coauthor Eric B. Larson, MD, MPH. “This latest study is a prime example of that work and has important implications for people taking medications—and for those prescribing medications for older patients.” Dr. Larson is the ACT principal investigator, vice president for research at Group Health, and executive director of Group Health Research Institute (GHRI). He is also a clinical professor of medicine at the UW School of Medicine and of health services at the UW School of Public Health.

Wednesday, January 28, 2015

Beer compound could help fend off Alzheimer's and Parkinson's diseases



The health-promoting perks of wine have attracted the spotlight recently, leaving beer in the shadows. But scientists are discovering new ways in which the latter could be a more healthful beverage than once thought. They're now reporting in ACS' Journal of Agricultural and Food Chemistry that a compound from hops could protect brain cells from damage -- and potentially slow the development of disorders such as Alzheimer's and Parkinson's diseases.

Jianguo Fang and colleagues note that mounting evidence suggests that oxidative damage to neuronal cells contributes to the development of diseases that originate in the brain. If scientists could find a way to guard these cells from this type of damage, they might be able to help prevent or slow down Alzheimer's disease, Parkinson's disease and other neurodegenerative conditions. One compound found in hops, called xanthohumol, has gotten the attention of researchers for its potential benefits, including antioxidation, cardiovascular protection and anticancer properties.

Fang's team decided to test xanthohumol's effects on brain cells.

In lab tests, the researchers found that the compound could protect neuronal cells and potentially help slow the development of brain disorders. The scientists conclude xanthohumol could be a good candidate for fighting such conditions.

Green tea ingredient may target protein to kill oral cancer cells




A compound found in green tea may trigger a cycle that kills oral cancer cells while leaving healthy cells alone, according to Penn State food scientists. The research could lead to treatments for oral cancer, as well as other types of cancer.

Earlier studies had shown that epigallocatechin-3-gallate -- EGCG -- a compound found in green tea, killed oral cancer cells without harming normal cells, but researchers did not understand the reasons for its ability to target the cancer cells, said Joshua Lambert, associate professor of food science and co-director of Penn State's Center for Plant and Mushroom Foods for Health. The current study shows that EGCG may trigger a process in the mitochondria that leads to cell death.

"EGCG is doing something to damage the mitochondria and that mitochondrial damage sets up a cycle causing more damage and it spirals out, until the cell undergoes programmed cell death," said Lambert. "It looks like EGCG causes the formation of reactive oxygen species in cancer cells, which damages the mitochondria, and the mitochondria responds by making more reactive oxygen species."

As this mitochondrial demise continues, the cancer cell also reduces the expression of anti-oxidant genes, further lowering its defenses.

"So, it's turning off its mechanism of protection at the same time that EGCG is causing this oxidative stress," Lambert added.
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The EGCG did not cause this reaction in normal cells.

In fact, it appeared to increase the protective capabilities of the cell, according to the researchers, who report their findings in the online issue of Molecular Nutrition and Food Research.

The researchers studied normal human oral cells side-by-side with human oral cancer cells to determine how EGCG was affecting cancer cells differently than normal cells. They grew the normal and cancer cells on petri dishes and then exposed them to EGCG, the major polyphenol found in green tea, at concentrations typically found in the saliva after chewing green-tea chewing gum. At various times, the researchers would collect the cells and check for oxidative stress and signs of antioxidant response.

"We also took a lot of pictures, so we could use fluorescent dyes that measure mitochondrial function and oxidative stress and actually see these things develop," said Lambert, who worked with Jong-Yung Park, a research technician and Ling Tao, a doctoral candidate in food science.

The researchers said that a protein called sirtuin 3 -- SIRT3 -- is critical to the process.

"It plays an important role in mitochondrial function and in anti-oxidant response in lots of tissues in the body, so the idea that EGCG might selectively affect the activity of sirtuin 3 in cancer cells -- to turn it off -- and in normal cells -- to turn it on -- is probably applicable in multiple kinds of cancers," Lambert said.

The study builds on earlier research on how EGCG affected oral cancer, a disease that is expected to kill more than 8,000 people in the United States this year.

"We've published one paper previously just looking at the effect of these green tea polyphenols on oral cancer cells in cultures, and there have been other papers published using oral cancer cells and at least a couple of animal model studies that have looked at oral cancer and prevention of oral cancer," said Lambert.

He said the next step would be to study the mechanism in animals. If those tests and human trials are successful, the researchers then hope to create anti-cancer treatments that are as effective as current treatments without the harmful side effects.

"The problem with a lot of chemotherapy drugs -- especially early chemotherapy drugs -- is that they really just target rapidly dividing cells, so cancer divides rapidly, but so do cells in your hair follicles and cells in your intestines, so you have a lot of side effects," said Lambert. "But you don't see these sorts of side effects with green tea consumption."

Thursday, January 22, 2015

Drinking moderate amounts of alcohol is linked to reduced risk of heart failure

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Evidence already exists for the beneficial effects of drinking moderate amounts of alcohol on the risk of developing a number of heart conditions; however, the role it plays in the risk of developing heart failure has been under-researched with conflicting results.

Now, a large study of nearly 15,000 men and women, published online January 20, 2015 in the European Heart Journal, shows that drinking up to seven drinks a week in early to middle age is associated with a 20% lower risk of men developing heart failure in the future when compared to people who did not drink at all, and a more modest 16% reduced risk for women.

Heart failure is a condition in which the heart can no longer pump blood around the body as well as it used to. The most common reason is that the heart muscle has been damaged, for instance by a heart attack. High blood pressure, heart muscle disease (cardiomyopathy), heart valve problems, an irregular heart beat (arrhythmia), viral infections, drinking excessive amounts of alcohol, consuming recreational drugs and the side-effects of radiotherapy treatment for cancer can all contribute to heart failure developing. Heart failure is a major public health problem with over 23 million people living with it worldwide.

Dr Scott Solomon, Professor of Medicine at Harvard Medical School and Senior Physician at Brigham and Women's Hospital, Boston, USA, Dr Alexandra Gonçalves, a research fellow at Brigham and Women's Hospital, and colleagues analysed data from 14,629 people aged between 45-64 years who had been recruited to the Atherosclerosis Risk in Communities Study between 1987 and 1989 in four communities in the USA. They followed the participants for 24-25 years to the end of 2011, and they questioned them about their alcohol consumption at the start and at each of the three subsequent visits made at three-yearly intervals.

They defined a drink as one that contains 14g of alcohol, equivalent to approximately one small (125ml) glass of wine, just over half a pint or a third of a litre of beer, and less than one shot of liquor such as whisky or vodka. The study participants were divided into six categories: abstainers (people who recorded having drunk no alcohol at every visit by the researchers), former drinkers, people who drank up to seven drinks a week, or between 7-14 drinks, 14-21 drinks, or 21 or more drinks a week.

During the follow-up period 1271 men and 1237 women developed heart failure. The lowest rate of heart failures occurred in those drinking up to 7 drinks per week and the highest rate was seen among former drinkers.

After taking account of various factors that could affect the results such as age, diabetes, high blood pressure, heart disease or heart attacks, body mass index, cholesterol levels, physical activity, education and smoking, men who consumed up to seven drinks a week had a 20% reduced risk of developing heart failure compared to abstainers, while the risk was reduced by 16% in women consuming the same amount. Former drinkers had the highest risk of developing heart failure -- a 19% and 17% increased risk among men and women respectively compared to abstainers. Interestingly, among both men and women consuming the most amount of alcohol (14 or more drinks a week), the risk of heart failure was not significantly different compared to the risk for abstainers. Drinking excessive amounts of alcohol over a long period of time is known to increase the risk of cardiomyopathy. However, the number of very heavy drinkers in the study was small, which could have limited its power to detect such an association.

However, when the researchers looked at death from any cause, there was an increased risk of death of 47% for men and 89% of women who reported consuming 21 or more drinks a week at the start of the study.

Professor Solomon said: "These findings suggest that drinking alcohol in moderation does not contribute to an increased risk of heart failure and may even be protective. No level of alcohol intake was associated with a higher risk of heart failure. However, heavy alcohol use is certainly a risk factor for deaths from any cause.

"The people who were classified as former drinkers at the start of the study had a higher risk of developing heart failure and of death from any cause when compared with abstainers. This could be related to the reasons why they had stopped drinking in the first place, for instance because they had already developed health problems that might have made them more likely to go on to develop heart failure."

The protective effect of moderate drinking were more marginal in women than in men and the authors think this may be due to the fact that women metabolise alcohol in a different way to men and it can affect them differently.

Overall, most participants were abstainers (42%) or former drinkers (19%), with 25% reporting up to seven drinks a week, eight percent reporting seven to 14 drinks a week, and three percent reporting drinking 14-21 and 21 or more drinks a week respectively. Most drinkers also drank more than one type of drink. This meant that the researchers were unable to assess the role of binge drinking or any differences between types of drink.

"It is important to bear in mind that our study shows there is an association between drinking moderate amounts of alcohol and a lower risk of heart failure but this does not necessarily mean that moderate alcohol consumption causes the lowered risk, although we did adjust our results to take account, as far as possible, for a variety of other lifestyle factors that could affect a person's risk," concluded Professor Solomon.


Wednesday, January 21, 2015

Comparing organic and conventional milk

Consumers perceive that organic cow milk differs from conventionally produced milk and that these differences justify the premium price for organic milk. In a review published in the Journal of Dairy Science®, researchers in New Zealand found that the differences between organic and conventional milk are not so straightforward.

Reviewing almost 200 publications, researchers concluded that previously conducted controlled studies investigating whether differences exist between organic and conventionally produced milk have so far been largely ambiguous, due principally to the complexity of the research question and the number of factors and variables that can influence milk composition. "This review presents one of the most detailed treatises to date of organic versus conventional milk composition," commented Matt Lucy, PhD, Professor of Animal Science, University of Missouri, and Editor-in-Chief of the Journal of Dairy Science®.

"When comparing organic and conventional milk composition (especially milk fatty acids), previous studies have generally compared organic dairying with milk produced from grass-fed cows to conventional dairying with milk produced from concentrate-fed cows. The differences in milk composition observed are actually due to the different diets of the cows (i.e. pasture versus concentrate feeding) rather than organic versus conventional farming systems," according to lead investigator Don Otter, PhD, Senior Scientist, Food & Bio-based Products, AgResearch Grasslands Research Centre (New Zealand).

Because there are many factors that affect milk composition, it is difficult to control for all of them when comparing organic to conventional milk production. According to the investigators, "The term 'organic' when applied to dairying is not universal, and to a large extent, is defined simply by regulations that differ from one country to the next. 'Conventional' basically is anything that is not 'organic.' However, in most parts of the world, conventional dairying is associated with high levels of grain feeding, the use of cow breeds which produce high milk volumes, and the application of large amounts of fertilizer ('high input' farming), while organic dairying is tied to pasture and forage feeding, lower amounts of fertilizer application, and the use of mixed or minority breeds ('low input'). The vast majority of differences reported between organic and conventional milk come from what cows are fed and their breed, and is not anything unique to being organic or conventional in itself."

Therefore in terms of nutrients in milk, there is nothing distinct about organic milk that makes it unique from conventionally produced milk once the different factors that influence milk production are compared or adjusted for. If animal genetics, health, breed, diet, management, or environment differs, then so will the composition of the milk produced.

Fatty acids in fish may shield brain from mercury damage



New findings from research in the Seychelles provide further evidence that the benefits of fish consumption on prenatal development may offset the risks associated with mercury exposure. In fact, the new study, which appeared January 20, 2015 in the American Journal of Clinical Nutrition, suggests that the nutrients found in fish have properties that protect the brain from the potential toxic effects of the chemical. 

Three decades of research in the Seychelles have consistently shown that high levels of fish consumption by pregnant mothers - an average of 12 meals per week - do not produce developmental problems in their children. Researchers have previously equated this phenomenon to a kind of biological horse race, with the developmental benefits of nutrients in fish outpacing the possible harmful effects of mercury also found in fish. However, the new research indicates that this relation is far more complex and that compounds present in fish - specifically polyunsaturated fatty acids (PUFA) - may also actively counteract the damage that mercury causes in the brain. 

"These findings show no overall association between prenatal exposure to mercury through fish consumption and neurodevelopmental outcomes," said Edwin van Wijngaarden, Ph.D., and associate professor in the University of Rochester Department of Public Health Sciences and a co-author of the study. "It is also becoming increasingly clear that the benefits of fish consumption may outweigh, or even mask, any potentially adverse effects of mercury." 

"This research provided us the opportunity to study the role of polyunsaturated fatty acids on development and their potential to augment or counteract the toxic properties of mercury," said Sean Strain, Ph.D., a professor of Human Nutrition at the Ulster University in Northern Ireland and lead author of the study. "The findings indicate that the type of fatty acids a mother consumes during pregnancy may make a difference in terms of their child's future neurological development." 

The new study comes as the U.S. Food and Drug Administration and international agencies are in the process of revisiting fish consumption advisories to better reflect the health benefits of nutrients found in fish. The FDA's current guidance - which recommends that pregnant women limit their consumption of certain fish to twice a week - was established because of the known risk of high level mercury exposure on childhood development.

Mercury is found in the environment as a result of both natural and human (e.g. coal plant emissions) activity. Much of it ends up being deposited in the world's oceans and, as a result, fish harbor the chemical in very small amounts. 

This has given rise to concerns that the cumulative impact of prenatal exposure to mercury through fish consumption may have negative health outcomes, despite the fact that that a link between low-level exposure and developmental consequences in children has never been definitively established. 

At the same time, fish are rich in a host of beneficial nutrients, including fatty acids, which are essential to brain development, leading to a long-standing exchange among scientists, environmentalists, and policymakers over the risk vs. benefit of fish consumption. This debate has significant consequences for global health, as billions of people across the world rely on fish as their primary source of protein. 

The Seychelles Child Development Study - a partnership between the University of Rochester Ulster University, and the Republic of Seychelles Ministry of Health and Education - is one of the longest and largest population studies of its kind. The Seychelles, a cluster of islands in the Indian Ocean, has proven to be the ideal location to examine the potential health impact of persistent low-level mercury exposure. The nation's 89,000 residents consume fish at a rate 10 times greater than the populations of the U.S. and Europe. 

The study published today followed more than 1,500 mothers and their children. At 20 months after birth, the children underwent a battery of tests designed to measure their communication skills, behavior, and motor skills. The researchers also collected hair samples from the mothers at the time of their pregnancy to measure the levels of prenatal mercury exposure. 

The researchers found that mercury exposure did not correlate with lower test scores. This finding tracked with the results of previous studies by the group - some of which have followed children in the Seychelles into their 20s - that have also shown no association between fish consumption and subsequent neurological development. 

The researchers also measured the PUFA levels present in the pregnant women and found that the children of mothers with higher levels of fatty acids known as n3 - the kind found in fish - performed better on certain tests. Another common form of PUFA, called n6, comes from other meats and cooking oils and is found in greater abundance in the diets of residents of developed countries. 

The fatty acids in fish (n3) are known to have anti-inflammatory properties, compared to n6, which can promote inflammation. One of the mechanisms by which mercury inflicts its damage is through oxidation and inflammation and this has led the researchers to speculate that not only does n3 provide more benefit in terms of brain development, but that these compounds may also counteract the negative effects of mercury.

This was reflected in the study's findings, which showed that the children of mothers with relatively higher levels of n6 did poorer on tests designed to measure motor skills.

"It appears that relationship between fish nutrients and mercury may be far more complex than previously appreciated," said Philip Davidson, Ph.D., the principal investigator of the Seychelles Child Development Study, a professor emeritus at the University of Rochester, and senior author of the study. "These findings indicate that there may be an optimal balance between the different inflammatory properties of fatty acids that promote fetal development and that these mechanisms warrant further study."

Health Benefits of Orange Juice



Many health advocates advise people to eat an orange and drink water rather than opt for a serving of sugary juice. But in ACS' Journal of Agricultural and Food Chemistry, scientists report that the picture is not clear-cut. Although juice is indeed high in sugar, the scientists found that certain nutrients in orange juice might be easier for the body to absorb than when a person consumes them from unprocessed fruit.

Ralf Schweiggert, Julian Aschoff and colleagues note that oranges are packed with nutrients such as carotenoids and flavonoids that, among other benefits, can potentially help lower a person's risk for certain cancers and cardiovascular disease. But many people prefer to drink a glass of orange juice rather than eat the fruit. Sugar content aside, are they getting the same nutritional benefits? Schweiggert's team set out to answer that question.

The researchers found that the production of pasteurized orange juice slightly lowered the levels of carotenoids and vitamin C. But at the same time, it significantly improved the carotenoid and vitamin C bioaccessibility -- or how much the body can absorb and use. And contrary to conventional wisdom, although juicing oranges dramatically cut flavonoid levels, the remaining ones were much more bioaccessible than those in orange segments.

Walnuts May Improve Memory


Eating walnuts may improve performance on cognitive function tests, including those for memory, concentration and information processing speed according to new research from the David Geffen School of Medicine at The University of California, Los Angeles, led by Dr. Lenore Arab. Cognitive function was consistently greater in adult participants that consumed walnuts, regardless of age, gender or ethnicity.

This cross-sectional study is the first large representative analysis of walnut intake and cognitive function, and the only study to include all available cognitive data across multiple National Health and Nutrition Examination (NHANES) surveys. The NHANES surveys draw from a large sampling of the U.S. population, typically ages 1 to 90 years old. In this study, participants included adults ages 20-59 as well as 60 and over. Dr. Arab and co-researcher Dr. Alfonso Ang found that study participants with higher walnut consumption performed significantly better on a series of six cognitive tests.

Dr. Arab noted, “It is exciting to see the strength of the evidence from this analysis across the U.S. population supporting the previous results of animal studies (1,2,3) that have shown the neuroprotective benefit from eating walnuts; and it’s a realistic amount – less than a handful per day (13 grams).” The study adds to a growing body of research surrounding walnuts’ positive effect on reducing cognitive impairment and overall brain health, (4) which includes the possible beneficial effects of slowing or preventing the progression of Alzheimer’s disease in mouse models. (5)

As the baby boomer population grows older, conditions affecting memory such as Alzheimer’s and dementia will become a greater concern. According to a 2012 World Health Organization article, the estimated number of new cases of dementia each year worldwide is nearly 7.7 million, and the number of people living with dementia worldwide is estimated at 35.6 million. This number is predicted to double by 2030 and more than triple by 2050. (6)

There are numerous possible active ingredients in walnuts that may be contributing factors in protecting cognitive functions. This includes the high antioxidant content of walnuts (3.7 mmol/ounce), (7) the combination of numerous vitamins and minerals as well as the fact that they are the only nut that contain a significant source of alpha-linolenic acid (ALA) (2.5 grams per ounce), a plant-based omega-3 fatty acid with heart and brain-health benefits. (8)

“It isn’t every day that research results in such simple advice – eating a handful of walnuts daily as a snack, or as part of a meal, can help improve your cognitive health,” said Dr. Arab.

Footnotes:


1.       Derek R. Fisher, Shibu M. Poulose, Donna F. Bielinski, Barbara Shukitt-Hale, (2014) Serum metabolites from walnut-fed aged rats attenuate stress-induced neurotoxicity in BV-2 microglial cells. Nutritional Neuroscience 0 (0).
2.       Poulose, Shibu M. et al. (2012) Walnut diet reduces accumulation of polyubiquitinated proteins and inflammation in the brain of aged rats. Journal of Nutritional Biochemistry, Volume 24, Issue 5, 912 – 919.
3.       Lauren M. Willis, Barbara Shukitt-Hale, Vivian Cheng and James A. Joseph (2009). Dose-dependent effects of walnuts on motor and cognitive function in aged rats. British Journal of Nutrition, 101, pp 1140-1144.
4.       Pribis P, Shukitt-Hale B (2014) Cognition: The New Frontier for Nuts and Berries. Am J Clin Nutr 100(suppl):347S-52S.
5.       Muthaiyah B, Essa MM, Lee M, Chauhan V, Kaur K, Chauhan A, (2014) Dietary Supplementation of Walnuts Improves Memory Deficits and Learning Skills in Transgenic Mouse Model of Alzheimer’s Disease. J Alzheimers Dis 42(4):1397-1405.
6.       10 Facts on Dementia. (2012 April). Retrieved from http://www.who.int/features/factfiles/dementia/en/
7.       Halvorsen BL, Carlsen MH, Phillips KM, Bohn SK, Holte K, Jacobs DR, Blomhoff R (2006) Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States. Am J Clin Nutr 84, 95-135.
8.       Fleming J, Kris-Etherton P, (2014) The Evidence for α-Linolenic Acid and Cardiovascular Disease Benefits: Comparisons with Eicosapentaenoic Acid and Docosahexaenoic Acid. Adv Nutr (5): 863S-876S.


Tuesday, January 20, 2015

Regular exercise may boost brain health in adults


In the brain, blood flow and cognitive function peak during young adulthood, but a new study of 52 young women found that oxygen availability, which is known to positively relate to brain health and function, is higher in adults who exercise regularly. Women who exercised on a regular basis had higher oxygen availability in the anterior frontal region of the brain and performed best on difficult cognitive tasks.

"Our findings suggest that regular engagement in physical activity may improve brain functioning even in young adults in their prime," said Dr. Liana Machado, senior author of the Psychophysiology study. "Both blood supply to the brain and cognitive functioning appear to benefit from regular exercise.

Sitting too long = higher risk of heart disease, diabetes, cancer, and death


The amount of time a person sits during the day is associated with a higher risk of heart disease, diabetes, cancer, and death, regardless of regular exercise, according to a review study published 
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today in the Annals of Internal Medicine.


"More than one half of an average person's day is spent being sedentary -- sitting, watching television, or working at a computerr," said Dr. David Alter, Senior Scientist, Toronto Rehab, University Health Network (UHN), and Institute for Clinical Evaluative Sciences. "Our study finds that despite the health-enhancing benefits of physical activity, this alone may not be enough to reduce the risk for disease."
The meta-analysis study reviewed studies focused on sedentary behaviour. The lead author is Avi Biswas, PhD candidate, Toronto Rehab, UHN and the Institute of Health Policy, Management and Evaluation, University of Toronto, and the senior author is Dr. Alter, who is also Associate Professor of Medicine, University of Toronto.

The authors found the negative effects of sitting time on health, however, are more pronounced among those who do little or no exercise than among those who participate in higher amounts of exercise.

"The findings suggest that the health risk of sitting too much is less pronounced when physical activity is increased," said Biswas. "We need further research to better understand how much physical activity is needed to offset the health risks associated with long sedentary time and optimize our health."

Future research will help determine what interventions, in addition to physical activity, are effective against the health risk of sedentary time.

"Avoiding sedentary time and getting regular exercise are both important for improving your health and survival," said Dr. Alter. "It is not good enough to exercise for 30 minutes a day and be sedentary for 23 and half hours."

In the interim, Dr. Alter underlines strategies people can use to reduce sitting time. The target is to decrease sedentary time by two to three hours in a 12-hour day.

"The first step is to monitor sitting times -- once we start counting, we're more likely to change our behaviour," said Dr. Alter. "Next is setting achievable goals and finding opportunities to incorporate greater physical activity -- and less time sitting -- into your daily life. For example, at work, stand up or move for one to three minutes every half hour; and when watching television, stand or exercise during commercials."

Monday, January 19, 2015

Health Benefits of Almonds, Pecans and Macadamia Nuts



Miscellaneous Nuts


Almonds reduce the risk of heart disease, research shows

Eating almonds can reduce the risk of heart disease by keeping blood vessels healthy, research has shown. Research found that they significantly increase the amount of antioxidants in the blood stream, reduce blood pressure and improve blood flow. These findings add weight to the theory that Mediterranean diets with lots of nuts have big health benefits.

Scientists have found that eating almonds in your diet can reduce the risk of heart disease by keeping blood vessels healthy.

Research found that they significantly increase the amount of antioxidants in the blood stream, reduce blood pressure and improve blood flow. These findings add weight to the theory that Mediterranean diets with lots of nuts have big health benefits.

The study was led by Professor Helen Griffiths, Professor in Biomedical Sciences and Executive Dean of the School of Life and Health Sciences at Aston University in Birmingham, UK. Researchers tested the effects of a short-term almond-enriched diet on healthy young and middle-aged men as well as on a group of young men with cardiovascular risk factors including having high blood pressure or being overweight.

A control group ate what they normally would, while another group consumed snacks of 50g of almonds a day for one month.

At the end of the study period, the group eating an almond-enriched diet had higher levels of antioxidants (alpha-tocopherol) in their blood stream, improved blood flow and lower blood pressure, potentially reducing their risk of heart disease.

Almonds are known to contain a range of beneficial substances such as vitamin E and healthy fats, fibre which increases the sense of fullness, and flavonoids which may have antioxidant properties. The team believes it is likely to be the combination of all these nutrients working together to create the overall health benefits rather than just one particular nutrient in isolation.

Professor Griffiths said: "Our study confirms that almonds are a superfood. Previous studies have shown that they keep your heart healthy, but our research proves that it isn't too late to introduce them into your diet -- adding even a handful (around 50g) every day for a short period can help. You could replace a daytime snack with a bag of almonds or add them to your regular meals like porridge or muesli to help reduce your risk of heart problems."

 

Antioxidants in pecans may contribute to heart health and disease prevention


A new research study from Loma Linda University (LLU) demonstrates that naturally occurring antioxidants in pecans may help contribute to heart health and disease prevention; the results were published in the January 2011 issue of The Journal of Nutrition.

Pecans contain different forms of the antioxidant vitamin E—known as tocopherols, plus numerous phenolic substances, many of them with antioxidant abilities. The nuts are especially rich in one form of vitamin E called gamma-tocopherols. The findings illustrate that after eating pecans, gamma-tocopherol levels in the body doubled and unhealthy oxidation of LDL (bad) cholesterol in the blood decreased by as much as 33 percent. Oxidized LDLs may further contribute to inflammation in the arteries and place people at greater risk of cardiovascular problems.

"Our tests show that eating pecans increases the amount of healthy antioxidants in the body," says LLU researcher Ella Haddad, DrPH, associate professor in the School of Public Health department of nutrition. "This protective effect is important in helping to prevent development of various diseases such as cancer and heart disease."

These findings are from a research project designed to further evaluate the health benefits of pecans, according to Dr. Haddad. She analyzed biomarkers in blood and urine samples from study participants (a total of 16 men and women between the ages 23 and 44) who ate a sequence of three diets composed of whole pecans, pecans blended with water, or a control meal of equivalent nutrient composition. The pecan meals contained about three ounces of the nut. Samples were taken prior to meals and at intervals up to 24 hours after eating.

Following the test meals composed of whole pecans and blended pecans, researchers found that amounts of gamma-tocopherols (vitamin E) in the body doubled eight hours after both meals, and oxygen radical absorbance capabilities (ORAC—a scientific method for measuring antioxidant power in the blood) increased 12 and 10 percent respectively two hours after the meals. In addition, following the whole-pecan meal, oxidized LDL cholesterol decreased by 30 percent (after 2 hours), 33 percent (after 3 hours), and 26 percent (after 8 hours).

"This study is another piece of evidence that pecans are a healthy food," says Dr. Haddad. "Previous research has shown that pecans contain antioxidant factors. Our study shows these antioxidants are indeed absorbed in the body and provide a protective effect against diseases."

Research from Loma Linda University published earlier in the Journal of Nutrition showed that a pecan-enriched diet lowered levels of LDL cholesterol by 16.5 percent—more than twice the American Heart Association's Step I diet, which was used as the control diet in that study. Similarly, the pecan-enriched diet lowered total cholesterol levels by 11.3 percent (also twice as much as the Step I diet).


Macadamia nuts good for the heart  


Incorporating macadamia nuts into a heart healthy diet can reduce cardiovascular disease risks according to Penn State researchers.

"We looked at macadamia nuts because they are not currently included in the health claim for tree nuts, while other tree nuts are recommended as part of a healthy diet," says Dr. Amy E. Griel, recent Ph.D. recipient in nutritional sciences. "Macadamia nuts have higher levels of monounsaturated fats, like those found in olive oil compared with other tree nuts."

The researchers used a controlled feeding study to compare a heart-healthy diet with 1.5 ounces – a small handful – of macadamia nuts to a standard American diet. The participants had slightly elevated cholesterol levels, normal blood pressure and were not taking lipid lowering drugs. Researchers randomly assigned participants to either the macadamia nut diet or the standard American diet and provided all meals for the participants for five weeks. The participants then switched diets and continued eating only food provided by the researchers for another five weeks.

The Healthy Heart diet with macadamia nuts did reduce total cholesterol, low-density lipoprotein cholesterol and triglyceride levels compared with the standard American diet.

"We observed a reduction in LDL similar to that seen with other tree nuts like walnuts and almonds," says Griel.

Individual calorie levels were used for each participant so that they did not gain or lose weight during the study. Both diets were matched for total fat, containing 33 percent calories from total fat. The Heart Healthy diet with macadamia nuts had 7 percent saturated fat, 18 percent monounsaturated fat and 5 percent polyunsaturated fat. The standard American diet had 13 percent saturated fat, 11 percent monounsaturated fat and 5 percent polyunsaturated fat.

The macadamia nut diet included macadamia nuts as a snack, mixed into meals, as a salad topping and in cookies and muffins.

"The total fat was the same in both diets," says Griel. "We substituted the macadamia nuts for other sources of fat and protein in the diet. For example, we could switch skim milk for 2 percent milk and add some macadamia nuts."

Health Benefits of Walnuts

New findings support the benefits of eating walnuts on overall health

Multiple new research abstracts suggest walnuts may have the potential to positively affect several important health factors. From their impact on colon cancer and certain aspects of cognitive aging, to their positive effect on both gut health and vascular health, the research findings presented at Experimental Biology 2015 (EB) detail our latest understanding of walnuts' inner workings. Running March 28 through April 1 in Boston, this annual meeting attracts an international audience of over 14,000 leading research scientists and exhibitors.

"These findings help advance the understanding of the many advantages of eating walnuts as part of a healthy diet, and add to the more than 159 published papers over 20 years that have shown how walnuts affect heart health, diabetes, cancer, cognition, fertility and weight management," said Dennis A. Balint, CEO, California Walnut Commission.

There are numerous possible active ingredients in walnuts that may be contributing factors in providing these health benefits. One component that differentiates walnuts is alpha-linolenic acid (ALA), the plant-based omega-3 fatty acid. Walnuts are the only nut that contain a significant amount of alpha-linolenic acid (ALA) with 2.5 grams per one ounce serving.

While scientific conclusions cannot yet be drawn from the abstracts presented at EB 2015, the following summaries share the latest findings:

  • Colon Cancer: For the first time, researchers looked at whether components of walnuts have an effect on colon cancer cells. This cell study1 was conducted by the Department of Nutritional Science and Food Management at the Ewha Womans University in Korea, and showed that walnut extract significantly slowed the survival of the cancer stem cells as well as reduced the stemness of colon cancer stem cells. Given the results, researchers state there is reason to further explore the role of walnut consumption in colon cancer therapies targeting cancer stem cells.
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  • Gut Health: The gut microbiome is an ecosystem of bacteria that helps our bodies digest and use the food we eat; changes in the gut microbiome are linked to chronic diseases. A recent animal study2 conducted by the Department of Physiology School of Medicine at Louisiana State University Health Sciences Center looked at the effect of walnuts on two major gut bacteria communities. A diet with walnuts (approximately 2 ounce human diet equivalent) significantly altered the ratio of the two communities, therefore suggesting "a new mechanism, changing the gut microbial environment, by which walnuts may exert their beneficial health effects." As this study was performed on animals, however, findings cannot yet be implied for humans.

  • Aging/Brain Health: This animal study3 from the Human Nutrition Research Center on Aging at Tufts University looked at healthy rats, both young and old, and the impact of walnuts - a source of polyunsaturated fatty acids and nutrients such as folate, selenium, magnesium and polyphenols - on mechanisms in critical regions of the brain. Animals were segmented into three groups - one, the control group, who ate no walnuts at all (0%); a second that had 6% of their diet comprised of walnuts; and a third that had 9% of their diet comprised of walnuts (equivalent to one ounce and 1.5 ounces respectively in a human diet). The groups were monitored for ten weeks. According to the researchers, incorporating walnuts into one's diet may have protective effects on the aging brain. As this study was performed on animals, however, findings cannot yet be implied for humans.

  • Vascular Health: Microvascular function refers to the health of our smallest blood vessels, such as capillaries. A study4 from the Departments of Nutrition and Internal Medicine at the University of California, Davis of postmenopausal women with high cholesterol looked at the short-term impact of walnut consumption. The group that ate 40 grams, or 1.5 ounces, of walnuts per day saw improved vascular function. The study concludes this improvement is due to the effects from the walnut-derived fatty acids, alpha-linolenic acid (ALA) and linoleic acid (LA).

Findings like these pave the way for additional research aimed at understanding walnuts' role in disease prevention and management.

 

 Walnuts May Improve Memory

Eating walnuts may improve performance on cognitive function tests, including those for memory, concentration and information processing speed according to new research from the David Geffen School of Medicine at The University of California, Los Angeles, led by Dr. Lenore Arab. Cognitive function was consistently greater in adult participants that consumed walnuts, regardless of age, gender or ethnicity.

This cross-sectional study is the first large representative analysis of walnut intake and cognitive function, and the only study to include all available cognitive data across multiple National Health and Nutrition Examination (NHANES) surveys. The NHANES surveys draw from a large sampling of the U.S. population, typically ages 1 to 90 years old. In this study, participants included adults ages 20-59 as well as 60 and over. Dr. Arab and co-researcher Dr. Alfonso Ang found that study participants with higher walnut consumption performed significantly better on a series of six cognitive tests.

Dr. Arab noted, “It is exciting to see the strength of the evidence from this analysis across the U.S. population supporting the previous results of animal studies (1,2,3) that have shown the neuroprotective benefit from eating walnuts; and it’s a realistic amount – less than a handful per day (13 grams).” The study adds to a growing body of research surrounding walnuts’ positive effect on reducing cognitive impairment and overall brain health, (4) which includes the possible beneficial effects of slowing or preventing the progression of Alzheimer’s disease in mouse models. (5)

As the baby boomer population grows older, conditions affecting memory such as Alzheimer’s and dementia will become a greater concern. According to a 2012 World Health Organization article, the estimated number of new cases of dementia each year worldwide is nearly 7.7 million, and the number of people living with dementia worldwide is estimated at 35.6 million. This number is predicted to double by 2030 and more than triple by 2050. (6)

There are numerous possible active ingredients in walnuts that may be contributing factors in protecting cognitive functions. This includes the high antioxidant content of walnuts (3.7 mmol/ounce), (7) the combination of numerous vitamins and minerals as well as the fact that they are the only nut that contain a significant source of alpha-linolenic acid (ALA) (2.5 grams per ounce), a plant-based omega-3 fatty acid with heart and brain-health benefits. (8)

“It isn’t every day that research results in such simple advice – eating a handful of walnuts daily as a snack, or as part of a meal, can help improve your cognitive health,” said Dr. Arab.

Footnotes:


1.       Derek R. Fisher, Shibu M. Poulose, Donna F. Bielinski, Barbara Shukitt-Hale, (2014) Serum metabolites from walnut-fed aged rats attenuate stress-induced neurotoxicity in BV-2 microglial cells. Nutritional Neuroscience 0 (0).
2.       Poulose, Shibu M. et al. (2012) Walnut diet reduces accumulation of polyubiquitinated proteins and inflammation in the brain of aged rats. Journal of Nutritional Biochemistry, Volume 24, Issue 5, 912 – 919.
3.       Lauren M. Willis, Barbara Shukitt-Hale, Vivian Cheng and James A. Joseph (2009). Dose-dependent effects of walnuts on motor and cognitive function in aged rats. British Journal of Nutrition, 101, pp 1140-1144.
4.       Pribis P, Shukitt-Hale B (2014) Cognition: The New Frontier for Nuts and Berries. Am J Clin Nutr 100(suppl):347S-52S.
5.       Muthaiyah B, Essa MM, Lee M, Chauhan V, Kaur K, Chauhan A, (2014) Dietary Supplementation of Walnuts Improves Memory Deficits and Learning Skills in Transgenic Mouse Model of Alzheimer’s Disease. J Alzheimers Dis 42(4):1397-1405.
6.       10 Facts on Dementia. (2012 April). Retrieved from http://www.who.int/features/factfiles/dementia/en/
7.       Halvorsen BL, Carlsen MH, Phillips KM, Bohn SK, Holte K, Jacobs DR, Blomhoff R (2006) Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States. Am J Clin Nutr 84, 95-135.
8.       Fleming J, Kris-Etherton P, (2014) The Evidence for α-Linolenic Acid and Cardiovascular Disease Benefits: Comparisons with Eicosapentaenoic Acid and Docosahexaenoic Acid. Adv Nutr (5): 863S-876S
Walnuts in one's diet can protect against diabetes and heart disease  

 Medical researchers from the Yale-Griffin Prevention Research Center in Connecticut have found evidence suggestive that adding walnuts to one's diet can protect against diabetes and heart disease in at-risk individuals. Their original research article, "Effects of Walnuts on Endothelial Function in Overweight Adults with Visceral Obesity: A Randomized, Controlled, Crossover Trial," published September 2013 in the Journal of the American College of Nutrition, the Official Publication of the American College of Nutrition.

For the study, a sample of 46 adults aged 30-75 were selected. Participants had a Body Mass Index larger than 25, and a waist circumference exceeding 40 inches for men and 35 inches for women. They were also required to be non-smokers, and all exhibited one or more additional risk factors for metabolic syndrome, a precursor of diabetes and cardiovascular disease. The group was randomly assigned to two 8-week sequences of either a walnut-enriched ad libitum diet or an ad libitum diet without walnuts. Those chosen for the walnut diet were instructed to consume 56g of shelled, unroasted English walnuts per day as a snack or with a meal.

"We know that improving diets tends to be hard, but adding a single food is easy," explained Dr. David Katz, Director of the Yale-Griffin Prevention Research Center and lead author of the research team. "Our theory is that if a highly nutritious, satiating food like walnuts is added to the diet, there are dual benefits: the benefits of that nutrient rich addition and removal of the less nutritious foods."

The research found that daily intake of 56g of walnuts improves endothelial function in overweight adults with visceral adiposity. The addition of walnuts to the diet does not lead to weight gain. Further study on the topic is still suggested. "The primary outcome measure was the change in flow-mediated vasodilatation (FMD) of the brachial artery," wrote the research group. "Secondary measures included serum lipid panel, fasting glucose and insulin, Homeostasis Model Assessment-Insulin Resistance values, blood pressure, and anthropometric measures. FMD improved significantly from baseline when subjects consumed a walnut-enriched diet as compared with the control diet. Beneficial trends in systolic blood pressure reduction were seen, and maintenance of the baseline anthropometric values was also observed. Other measures were unaltered.



Whole walnuts and their extracted oil improve cardiovascular disease risk  

Consumption of whole walnuts or their extracted oil can reduce cardiovascular risk through a mechanism other than simply lowering cholesterol, according to a team of Penn State, Tufts University and University of Pennsylvania researchers.

"We already know that eating walnuts in a heart-healthy diet can lower blood cholesterol levels," said Penny Kris-Etherton, Distinguished Professor of Nutrition, Penn State. "But, until now, we did not know what component of the walnut was providing this benefit. Now we understand additional ways in which whole walnuts and their oil components can improve heart health."

In a randomized-controlled trial, the researchers gave 15 participants with elevated blood cholesterol one of four treatments -- either 85 grams of whole walnuts, 6 grams of skin, 34 grams of defatted nutmeat, or 51 grams of oil. The team evaluated biochemical and physiological responses in the participants before the treatments were administered and again 30 minutes, one hour, two hours, four hours and six hours after administering the treatments. The researchers repeated this process for each of the remaining three treatments.

Results -- which appeared in the June 1 2013 issue of the Journal of Nutrition -- showed that a one-time consumption of the oil component in walnuts favorably affected vascular health. In addition, consumption of whole walnuts helped HDL -- good cholesterol -- perform more effectively in transporting and removing excess cholesterol from the body.

"Our study showed that the oil found in walnuts can maintain blood vessel function after a meal, which is very important given that blood vessel integrity is often compromised in individuals with cardiovascular disease," said Claire Berryman, graduate student in nutritional sciences, Penn State. "The walnut oil was particularly good at preserving the function of endothelial cells, which play an important role in cardiovascular health."

According to the researchers, walnuts contain alpha-linolenic acid, amma-tocopherol and phytosterols, which may explain the positive effects of the walnut oil treatment.

"Implications of this finding could mean improved dietary strategies to fight heart disease," said Berryman. "The science around HDL functionality is very new, so to see improvements in this outcome with the consumption of whole walnuts is promising and worth investigating further."

Further studies are needed to determine the mechanisms that account for cardiovascular disease risk reduction with walnut consumption, according to Kris-Etherton.

"Our study indicates that simple dietary changes, such as incorporating walnuts and/or their oil in a heart healthy diet, may reduce the risk of heart disease," she said.


Walnuts are top nut for heart-healthy antioxidants 

A new scientific study positions walnuts in the No. 1 slot among a family of foods that lay claim to being among Mother Nature's most nearly perfect packaged foods: Tree and ground nuts. In a report at the 241st National Meeting & Exposition of the American Chemical Society, March, 2011, scientists presented an analysis showing that walnuts have a combination of more healthful antioxidants and higher quality antioxidants than any other nut.

"Walnuts rank above peanuts, almonds, pecans, pistachios and other nuts," said Joe Vinson, Ph.D., who did the analysis. "A handful of walnuts contains almost twice as much antioxidants as an equivalent amount of any other commonly consumed nut. But unfortunately, people don't eat a lot of them. This study suggests that consumers should eat more walnuts as part of a healthy diet."

Vinson noted that nuts in general have an unusual combination of nutritional benefits — in addition those antioxidants — wrapped into a convenient and inexpensive package. Nuts, for instance, contain plenty of high-quality protein that can substitute for meat; vitamins and minerals; dietary fiber; and are dairy- and gluten-free. Years of research by scientists around the world link regular consumption of small amounts of nuts or peanut butter with decreased risk of heart disease, certain kinds of cancer, gallstones, Type 2 diabetes, and other health problems.

Despite all the previous research, scientists until now had not compared both the amount and quality of antioxidants found in different nuts, Vinson said. He filled that knowledge gap by analyzing antioxidants in nine different types of nuts: walnuts, almonds, peanuts, pistachios, hazelnuts, Brazil nuts, cashews, macadamias, and pecans. Walnuts had the highest levels of antioxidants.

Vinson also found that the quality, or potency, of antioxidants present in walnuts was highest among the nuts. Antioxidants in walnuts were 2-15 times as potent as vitamin E, renowned for its powerful antioxidant effects that protect the body against damaging natural chemicals involved in causing disease.

"There's another advantage in choosing walnuts as a source of antioxidants," said Vinson, who is with the University of Scranton in Pennsylvania. "The heat from roasting nuts generally reduces the quality of the antioxidants. People usually eat walnuts raw or unroasted, and get the full effectiveness of those antioxidants."

If nuts are so healthful and nutritious, why don't people eat more? Vinson's research shows, for instance, that nuts account for barely 8 percent of the daily antioxidants in the average person's diet. Many people, he said, may not be aware that nuts are such a healthful food. Others may be concerned about gaining weight from a food so high in fat and calories. But he points out that nuts contain healthful polyunsaturated and monosaturated fats rather than artery-clogging saturated fat. As for the calories, eating nuts does not appear to cause weight gain and even makes people feel full and less likely to overeat. In a 2009 U. S. study, nut consumption was associated with a significantly lower risk of weight gain and obesity. Still, consumers should keep the portion size small. Vinson said it takes only about 7 walnuts a day, for instance, to get the potential health benefits uncovered in previous studies.


Walnuts, walnut oil, improve reaction to stress  


A diet rich in walnuts and walnut oil may prepare the body to deal better with stress, according to a team of Penn State researchers who looked at how these foods, which contain polyunsaturated fats, influence blood pressure at rest and under stress.

Previous studies have shown that omega-3 fatty acids -- like the alpha linolenic acid found in walnuts and flax seeds -- can reduce low density lipoproteins (LDL) -- bad cholesterol. These foods may also reduce c-reactive protein and other markers of inflammation.

"People who show an exaggerated biological response to stress are at higher risk of heart disease," said Sheila G. West, associate professor of biobehavioral health. "We wanted to find out if omega 3-fatty acids from plant sources would blunt cardiovascular responses to stress."

The researchers studied 22 healthy adults with elevated LDL cholesterol. All meals and snacks were provided during three diet periods of six weeks each.

The researchers found that including walnuts and walnut oil in the diet lowered both resting blood pressure and blood pressure responses to stress in the laboratory. Participants gave a speech or immersed their foot in cold water as a stressor. Adding flax seed oil to the walnut diet did not further lower blood pressure. They report their findings in the current issue of the Journal of the American College of Nutrition.

"This is the first study to show that walnuts and walnut oil reduce blood pressure during stress," said West. "This is important because we can't avoid all of the stressors in our daily lives. This study shows that a dietary change could help our bodies better respond to stress."

A subset of the participants also underwent a vascular ultrasound in order to measure artery dilation. Results showed that adding flax oil to the walnut diet significantly improved this test of vascular health. The flax plus walnuts diet also lowered c-reactive protein, indicating an anti-inflammatory effect. According to West, that could also reduce risk of cardiovascular disease.

The researchers used a randomized, crossover study design. Tests were conducted at the end of each six-week diet, and every participant consumed each of the three diets in random order, with a one-week break between. Diets included an "average" American diet – a diet without nuts that reflects what the typical person in the U.S. consumes each day. The second diet included 1.3 ounces of walnuts and a tablespoon of walnut oil substituted for some of the fat and protein in the average American diet. The third diet included walnuts, walnut oil and 1.5 tablespoons of flaxseed oil. The three diets were matched for calories and were specifically designed for each participant so that no weight loss or gain occurred. The walnuts, walnut oil, and flax oil were either mixed into the food in such offerings as muffins or salad dressing or eaten as a snack. About 18 walnut halves or 9 walnuts make up the average serving used by the researchers.

After each diet, the participants underwent two stress tests. In the first test, they received a topic; and they were given two minutes to prepare a three-minute speech, which they presented while being videotaped. The second stressor was a standard physical test of stress consisting of submerging one foot in ice-cold water. Throughout these tests, the researchers took blood pressure readings from the participants.

Results showed that average diastolic blood pressure -- the "bottom number" or the pressure in the arteries when the heart is resting -- was significantly reduced during the diets containing walnuts and walnut oil.

Walnuts are a rich source of fiber, antioxidants, and unsaturated fatty acids, particularly alpha linolenic acid, an omega-3 fatty acid, and these compounds could be responsible for the beneficial effects on blood pressure. Flax oil is a more concentrated source of omega-3 fatty acids than walnut oil, but this study did not test whether flax oil alone could blunt cardiovascular responses to stress.

"These results are in agreement with several recent studies showing that walnuts can reduce cholesterol and blood pressure," noted West. "This work suggests that blood pressure is also reduced when a person is exposed to stress in their daily life."