Thursday, April 28, 2011

Lower risk of coronary heart disease from alcohol

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even with hazardous drinking

The analysis assesses the 12-month prevalence of coronary heart disease (CHD) in individuals according to their category of alcohol use. The 2001 National Epidemiologic Survey on Alcohol and Related Conditions study (the NESARC study, n = 43,093) identified 16,147 abstinent individuals, 15,884 moderate consumers, 9,578 hazardous drinkers — defined as exceeding sex-specific weekly limits established by the World Health Organization, and 1,484 alcohol-dependent subjects. Diagnoses were generated using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV version. Both moderate and hazardous drinking were associated with decreased odds of CHD when compared with abstinence, whereas odds of CHD were not significantly different between alcohol-dependent and abstinent participants. A moderate or even a hazardous consumption of alcohol was associated with a decreased likelihood of CHD after controlling for socio-demographic, psychiatric, and addictive risk factors. Our study shows that alcohol may have cardio-protective effects not only in moderate drinkers, but also in individuals with patterns of use traditionally considered as hazardous.

International Scientific Forum on Alcohol Research Comments

There were adequate numbers of subjects in most analysis groups, in that 36% of subjects were abstinent in the last year and almost one quarter of subjects were in the group classified as "hazardous drinking." One Forum reviewer commented: "This exhibition of a rightward extension of the revered J-shaped curve for coronary heart disease (CHD) has been reported before. I find the results acceptable. I wonder, however, what happens to the rates of cirrhosis and other directly alcohol-related disorders and what might be the long-term total mortality experience in this group." An interesting finding in this study is that participants with CHD were more likely to have lifetime mood disorder, lifetime anxiety disorder, and personality disorder than those without CHD.

If indeed the risk of coronary disease does not increase despite consuming alcohol at a level often classified as "hazardous," it is possible that the increase in cardiovascular disease from heavy drinking reported in many studies may be due to arrhythmias, cardiomyopathy, or other heart conditions that are not actually coronary artery disease.

Limitations to paper: Appropriate socio-economic variables were available for adjustment for confounding, with good assessments for alcohol intake, tobacco use, and drug abuse. However, sick quitters and unhealthy hazardous drinkers dying earlier than the healthy ones may have confounded the results. Further, unmeasured factors such as exercise and diet that were not adjusted for may have led to further confounding.

A key concern of Forum reviewers related to the method used to diagnose CHD in this analysis. Not only was it self-reported, but only 1.0% of cases stated that they had had a myocardial infarction, the primary "hard" criterion for CHD. Most reported angina pectoris, a "softer" criterion for coronary disease. Further, "arteriosclerosis" is a vague term and not one generally used in normal communication with patients. It could have referred to conditions other than CHD.

Most studies have found that frequent, light-to-moderate drinking is the healthiest approach for alcohol intake, and the average amount per week is an inadequate measure of intake. In this study, it is unclear whether or not the frequency of drinking was informative regarding CHD. Further, both rare, occasional, and regular drinkers who did not meet criteria for "hazardous drinking" were included in the "moderate" group, so it is not possible to separate daily drinkers from occasional drinkers.

The authors state that "Hazardous drinking was defined as exceeding sex-specific weekly limits as defined by the NIAAA (men, more that14 drinks of 14g per week; women, more than 7 drinks per week) or exceeding daily drinking limits (men,≥5 drinks per day;women,≥4 drinks per day) at least once in the past year." One possibility is that this definition of "hazardous drinking" is too restrictive, including some people who might better be classified as moderate drinkers. As a Forum reviewer commented: "The definition of "moderate drinking" is very strict and the subgroup with 'hazardous drinking' would include many European drinkers with no alcohol problems. The 'hazardous' subgroup includes really hazardous drinking associated with liver disease mortality and detrimental effects on other organs. The heterogeneity of the subgroup of 'hazardous drinkers' is a serious problem of the study."

The authors acknowledge this shortcoming, stating that " . . .the criteria used for the definition of the 'hazardous drinking' subgroup of subjects is too broad. Indeed, women having a little more than one drink every day and men having used five drinks in a single day only once in the previous year are both included in this group. This suggests that alcohol dependence and hazardous drinking should be routinely distinguished, and that a quantitative assessment of alcohol use may be more relevant than a qualitative approach when assessing the risk of cardiovascular disorders.'

Forum Summary: Using data from The 2001 National Epidemiologic Survey on Alcohol and Related Conditions study (the NESARC study, n = 43,093), the authors of this paper conclude that alcohol may have cardioprotective effects not only in moderate drinkers, but also in individuals with patterns of use traditionally considered as "hazardous." While such a finding has been shown in some population studies, there were questions by Forum reviewers as to the adequacy of the method for diagnosing coronary artery disease: self-report, with most subjects listing angina pectoris, a "soft" criterion for coronary disease.

In addition, the categories of drinking used in this study were very broad: rare or only occasional drinkers were combined with regular drinkers up to 7 or 14 drinks per week in the "moderate" category, and the "hazardous category" included a broad range of drinkers, from a minimal increase over the recommended limits to very heavy drinkers. The pattern of drinking (especially the number of days per week that alcohol was consumed) was not reported, making it difficult to separate regular from heavy week-end only drinkers. The effects of heavier drinking on other conditions (such as alcohol-related liver disease, mortality, etc.) were not included in this analysis.

It is physiologically possible that even hazardous use of alcohol, like moderate use, may well lead to cleaner arteries and therefore lower rates of coronary artery disease. If this is the case, an explanation for the increases in cardiovascular mortality reported for heavy drinkers in many studies may relate not directly to coronary artery disease, but to conditions such as cardiomyopathy or cardiac arrhythmias. However, the rates of accidents, suicide and other morbidity associated with hazardous alcohol use may well overcome any protective effects on coronary disease.

Americans still may not be getting enough calcium

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Americans may not be getting enough calcium in their diets, according to a new study published in the May 2011 issue of the Journal of the American Dietetic Association. This study is unique among those focusing on calcium intake in the US population because both dietary and supplemental sources were evaluated across adult age groups and compared to accompanying patterns in energy intake.

"Calcium plays a fundamental role in promoting bone health and forestalling osteoporosis. In light of evidence that energy intake declines with aging, calcium dense foods and calcium supplements become vital factors in maintaining adequate calcium intake across the lifespan," commented Jane E. Kerstetter, RD, PhD, Professor, Department of Allied Health Sciences, University of Connecticut. "Encouraging calcium supplementation is an established approach to addressing this issue in the clinical setting – one that needs additional emphasis in order to promote more frequent and sufficient supplementation in meeting adequate intake levels. Altering the concentration of calcium in the diet relative to energy by increasing consumption of nutrient dense foods is a new and important concept that also deserves additional consideration as a component of osteoporosis prevention efforts."

Using data collected from 9,475 adults during the National Health and Nutrition Examination Survey (NHANES) of 2003 to 2006, researchers from the University of Connecticut and Yale University found that while self-reported calcium density was highest in older age groups, it was still not sufficient to meet recommended levels. Although reported calcium supplement use increased with age in both men and women, median dietary calcium intake was lower in the 81+ age group by 23% in men and by 14% in 18 women, compared to the median intake reported in the 19-30 year age group. In relating calcium and energy intake, dietary calcium density as well as calcium supplementation play a critical role in attainment of established adequate intake levels.

The authors looked at the decrease in energy intake reported by various age groups. As people age, they consume less food, and therefore less calcium. Men's median energy intake declined by 35% from the 19-30 age group to the 81+ age group; from 2,668 kcal/d to 1,733 kcal/d. For women, median energy intake showed a 28% reduction from the youngest to oldest age group; from 1,844 kcal/d to 1,325 kcal/d.

Calcium supplements have become increasingly popular in recent years. Researchers found that 51% of all individuals ≥19 y of age were taking a calcium supplement. The percentage of individuals taking a calcium supplement increased in men from 34% in the 19-30 age group to 54% in the 81+ group. In women, these percentages rose from 42% to 64% across the range of age groups.

In an accompanying editorial, Susan M. Krebs-Smith, PhD, RD, and Sharon I. Kirkpatrick, PhD, RD, of the National Institutes of Health, National Cancer Institute, caution that attention to the details of the methodologies used is warranted in interpreting the results of this and similar studies. Comparing the current study with a recent publication by Bailey and colleagues1, they show that the varying statistical procedures applied to estimate calcium intake from survey data can lead to different conclusions. Even though both research groups were working from the same data, due to the application of different statistical techniques and assumptions, Bailey and colleagues' point estimates for median dietary calcium intakes for supplement users and nonusers combined are much higher than those of Kerstetter and colleagues.

According to Krebs-Smith and Kirkpatrick, "The juxtaposition of these two papers provides not only insights into calcium intakes among the population, but also highlights the impact that different statistical approaches to dietary assessment can have on the resulting estimates, pointing to the need for further research to identify optimal methods for assessing total intakes."

Muscle, Kidney Problems Linked to Kava Tea

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When a 34-year-old bicyclist was found collapsed on a roadside and rushed to the University of Rochester Medical Center emergency room on the verge of kidney failure and muscle breakdown, doctors were surprised to discover that a trendy tea derived from the kava plant was the cause of his ills.

The URMC team reported the case study, believed to be the first of its kind in the scientific literature, in the American Journal of Emergency Medicine. They described it as a cautionary tale, emphasizing the importance of taking a thorough medical history, including the use of any and all herbal remedies and pharmaceuticals.

In this instance the patient recovered; and doctors noted that adverse effects are somewhat rare. However, across the country the number of kava bars is on the rise – a recent article noted at least three new businesses in Palm Beach, Fla., -- despite several documented health problems due to kava ingestion.

“With the increased use of herbal remedies, we in the medical field have become accustomed to asking patients about their use,” said URMC Department of Emergency Medicine Chair Michael F. Kamali, M.D. “What concerns us is the lack of controls in producing and distributing these products as well as some lack of knowledge of the potential harm by those people using the product.”

Kava (Piper methysticum) is a plant in the pepper family that grows naturally throughout the western Pacific. Hawaiians have been using it for 3000 years for its sedating properties and as a celebratory drink. Regular drinkers of kava tea claim it eases anxiety, insomnia, and menopause symptoms. Some people drink it in place of alcohol.

The sale of kava root and its extract in pill form are legal in the United States and can be found on the Internet. However the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention have issued warnings due to concerns about liver and kidney toxicity.

The URMC patient told physicians he had been a longtime user, drinking kava tea a couple times a week for anxiety. But on this day, he said, he drank twice the amount as usual. When he arrived at URMC’s Strong Memorial Hospital, he was agitated, rigid and combative to the point that medical personnel had to physically and chemically restrain him, the case study said. Later he reported severe muscle weakness and fatigue, and routine blood tests revealed that his creatine kinase (CK) levels (which provide important information about the condition of the muscles, including the heart muscle) had soared to to 32,500 IU/L.

Typically doctors see CK levels that can be as low as 17 IU/L and still be normal, and as high as 400 IU/L. Abnormally high levels often indicate heart and brain damage, and lead to kidney failure. In this patient, it took six days of intense hydration and treatment to lower his levels to 2,066 IU/L. His kidney function was normal upon discharge.

Kamali and his team explained in the AJEM report that the active ingredients in kava are kavalactones, which create mild sedation without disrupting cognitive function. They also act as a muscle relaxant and decrease blood flow to the kidneys, and thus higher doses can have an effect similar to that of a local anesthetic.

The patient recalled riding his bicycle a normal distance (he often rode to work) but becoming so tired that he had to lie down to rest along the road. Ultimately, URMC physicians diagnosed him with rhabdomyolysis, the breakdown of muscle fibers that results in the release of a potentially harmful protein pigment called myoglobin into the bloodstream.

One possible explanation for the rhabdomyolysis in this patient, Kamali said, was that the kava induced muscle weakness that led to over-exertion and stress as the bicyclist attempted to go about his normal routine. Alternatively, the kava might have caused direct muscle toxicity, or the kava might have contained a foreign impurity.

Whatever the explanation, this situation reinforced the importance of taking a detailed medical history, particularly when symptoms of organ toxicity are evident.

Ryan P. Bodkin, M.D., the URMC Emergency Medicine chief resident who treated the patient, said most cases of toxic poisonings in the ED involve an overdose of standard medications such as Tylenol or anti-depressants, for instance; or alcohol abuse, or illegal drugs such as cocaine, marijuana or heroin.

“It is extremely unusual to see toxicity like this,” Bodkin said. “Liver damage from kava has been reported occasionally, and only one other case of myoglobinuria (muscle damage) has been reported. This is not to say it never happens, but we were fortunate to recognize it because it is so rare.”

Being tall, obese may significantly increase risk of blood clots in deep veins

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The combination of being tall and obese, particularly in men, may substantially raise the risk of developing potentially dangerous blood clots in veins deep in the body.
If you’re tall, you can reduce your risk by maintaining a healthy weight.
DALLAS, April 28, 2011 — Being tall and obese may increase your risk for potentially dangerous blood clots, according to new research in Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association.

Obesity is a well-known risk factor for clots in deep veins (usually in the legs) and for pulmonary embolism, a clot in blood vessels of the lungs that can result in sudden death or strain on the heart. Together, the two conditions are called venous thromboembolism (VTE).

Compared with short (5 feet, 7.7 inches or less) and normal-weight men (body mass index < 25kg/m2), the age-adjusted risk of VTE was:

· 5.28 times higher in obese and tall men

· 2.57 times higher in normal-weight and tall men (at least 5 feet, 11.7 inches tall)

· 2.11 times higher in obese and short men

The amount of risk conferred by being both obese and tall was comparable to other known risk factors for VTE, including pregnancy, the use of oral contraceptives, and carrying one gene for an inherited predisposition to clotting called Factor V Leiden.

Compared with short (5 feet, 2.6 inches or less) normal-weight women, the age-adjusted risk of VTE was:

· 2.77 times higher in obese and tall women

· 1.83 times higher in obese and short women

· Not increased in normal-weight and tall women (more than 5 feet, 6 inches)

“We believe that we observed the increased risk in tall and normal-weight men, but not women, because most women do not get sufficiently tall,” said Sigrid K. Braekkan, Ph.D., senior study author and a researcher in the Hematological Research Group at the University of Tromsø in Norway. “The risk may be present in very tall women, but there were too few to investigate this properly.”

Researchers said more studies are needed to determine the mechanisms of the association between tall stature, excess weight and the combination on the risk of VTEs.

“In tall people the blood must be pumped a longer distance by the calf-muscle pump, which may cause reduced flow in the legs and thereby raise the risk of clotting,” Braekkan said.

“Understanding and preventing VTE is important because even the first occurrence may be fatal. Obesity, in combination with other VTE risk factors, has been shown to substantially increase the risk, so we wanted to assess the combined effects of tall stature and obesity.”

The research team analyzed data from the Tromsø study, which conducts periodic health surveys of adults 25-97 years old in the Norwegian town. Researchers collected height and obesity measures on 26,714 men and women followed a median of 12.5 years between 1994 and 2007. During that time, 461 VTEs occurred.

Obesity causes increased pressure in the abdomen, which may reduce the ability of the calf-muscle pump to return the blood from the legs. “Obesity is also linked to a state of constant low-grade inflammation, and inflammation may render blood more susceptible to clotting,” Braekkan said.

Physicians should consider people’s height and weight as they assess their overall risk for dangerous clots, researchers said.

“Since body height is not easy to modify, the most important thing is to stay slim, especially if you are tall,” Braekkan said.

The researchers previously found a strikingly similar rise in clot risk along with height in American men, and believe that the height cut-offs would apply to Caucasian populations in other regions.

In the United States, more than 275,000 people each year are hospitalized with deep vein clots or pulmonary embolism, according to the American Heart Association.

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Monday, April 25, 2011

High percentage of omega-3s in the blood may boost risk of aggressive prostate cancer

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Conversely, high percentage of trans-fatty acids linked with lower risk


The largest study ever to examine the association of dietary fats and prostate cancer risk has found what's good for the heart may not be good for the prostate.

Analyzing data from a nationwide study involving more than 3,400 men, researchers at Fred Hutchinson Cancer Research Center found that men with the highest blood percentages of docosahexaenoic acid, or DHA, an inflammation-lowering omega-3 fatty acid commonly found in fatty fish, have two-and-a-half-times the risk of developing aggressive, high-grade prostate cancer compared to men with the lowest DHA levels.

Conversely, the study also found that men with the highest blood ratios of trans-fatty acids – which are linked to inflammation and heart disease and abundant in processed foods that contain partially hydrogenated vegetable oils – had a 50 percent reduction in the risk of high-grade prostate cancer. In addition, neither of these fats was associated with the risk of low-grade prostate cancer risk. The researchers also found that omega-6 fatty acids, which are found in most vegetable oils and are linked to inflammation and heart disease, were not associated with prostate cancer risk. They also found that none of the fats were associated with the risk of low-grade prostate cancer.

These findings by Theodore M. Brasky, Ph.D., and colleagues in the Hutchinson Center's Public Health Sciences Division were published online April 25 in the American Journal of Epidemiology.

"We were stunned to see these results and we spent a lot of time making sure the analyses were correct," said Brasky, a postdoctoral research fellow in the Hutchinson Center's Cancer Prevention Program. "Our findings turn what we know – or rather what we think we know – about diet, inflammation and the development of prostate cancer on its head and shine a light on the complexity of studying the association between nutrition and the risk of various chronic diseases."

The researchers undertook the study because chronic inflammation is known to increase the risk of several cancers, and the omega-3 fatty acids found primarily in fish and fish oil supplements have anti-inflammatory effects. In contrast, other fats, such as the omega-6 fats in vegetable oil and trans-fats found in fast foods, may promote inflammation. "We wanted to test the hypothesis that the concentrations of these fats in blood would be associated with prostate cancer risk," Brasky said. "Specifically, we thought that omega-3 fatty acids would reduce and omega-6 and trans-fatty acids would increase prostate cancer risk."

The mechanisms behind the impact of omega-3s on risk of high-grade prostate cancer are unknown. "Besides inflammation, omega-3 fats affect other biologic processes. It may be that these mechanisms play a greater role in the development of certain prostate cancers," Brasky said. "This is certainly an area that needs more research."

Currently there is no official recommended daily allowance for omega-3 fats for adults or children, although many nutrition experts and physicians recommend 450 milligrams of omega-3 DHA per day as part of a healthy diet.

The study was based on data from the Prostate Cancer Prevention Trial, a nationwide randomized clinical trial that tested the efficacy of the drug finasteride to prevent prostate cancer. While the trial involved nearly 19,000 men age 55 and older, the data in this analysis came from a subset of more than 3,000 of the study participants, half of whom developed prostate cancer during the course of the study and half of whom did not. The clinical trial was unique in that prostate biopsy was used to confirm the presence or absence of prostate cancer in all study participants.

Among the study participants, very few took fish oil supplements – the most common non-food source of omega-3 fatty acids, which are known to prevent heart disease and other inflammatory conditions. The majority got omega 3s from eating fish.

So based on these findings, should men concerned about heart disease eschew fish oil supplements or grilled salmon in the interest of reducing their risk of aggressive prostate cancer? Brasky and colleagues don't think so.

"Overall, the beneficial effects of eating fish to prevent heart disease outweigh any harm related to prostate cancer risk," Brasky said. "What this study shows is the complexity of nutrition and its impact on disease risk, and that we should study such associations rigorously rather than make assumptions," Brasky said.

Higher levels of social activity decrease the risk of cognitive decline

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If you want to keep your brain healthy, it turns out that visiting friends, attending parties, and even going to church might be just as good for you as crossword puzzles.

According to research conducted at Rush University Medical Center, frequent social activity may help to prevent or delay cognitive decline in old age. The study has just been posted online in the Journal of the International Neuropsychological Society.

The researchers were especially careful in their analysis to try to rule out the possibility that cognitive decline precedes, or causes, social isolation, and not the reverse.

"It's logical to think that when someone's cognitive abilities break down, they are less likely to go out and meet friends, enjoy a camping trip, or participate in community clubs. If memory and thinking capabilities fail, socializing becomes difficult," said lead researcher Bryan James, PhD, postdoctoral fellow in the epidemiology of aging and dementia in the Rush Alzheimer's Disease Center. "But our findings suggest that social inactivity itself leads to cognitive impairments."

The study included 1,138 older adults with a mean age of 80 who are participating in the Rush Memory and Aging Project, an ongoing longitudinal study of common chronic conditions of aging. They each underwent yearly evaluations that included a medical history and neuropsychological tests.

Social activity was measured based on a questionnaire that asked participants whether, and how often, in the previous year they had engaged in activities that involve social interaction—for example, whether they went to restaurants, sporting events or the teletract (off-track betting) or played bingo; went on day trips or overnight trips; did volunteer work; visited relatives or friends; participated in groups such as the Knights of Columbus; or attended religious services.

Cognitive function was assessed using a battery of 19 tests for various types of memory (episodic, semantic and working memory), as well as perceptual speed and visuospatial ability.

At the start of the investigation, all participants were free of any signs of cognitive impairment. Over an average of five years, however, those who were more socially active showed reduced rates of cognitive decline. On average, those who had the highest levels of social activity (the 90th percentile) experienced only one quarter of the rate of cognitive decline experienced by the least socially active individuals. Other variables that might have accounted for the increase in cognitive decline—such as age, physical exercise, and health—were all ruled out in the analysis.

Why social activity plays a role in the development of cognitive problems is not clear. According to James, one possibility is that "social activity challenges older adults to participate in complex interpersonal exchanges, which could promote or main efficient neural networks in a case of 'use it or lose it.'"

Future research is needed to determine whether interventions aimed at increasing late-life social activity can play a part in delaying or preventing cognitive decline, James said.

Thursday, April 21, 2011

Are dietary supplements working against you?

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Do you belong to the one-half of the population that frequently uses dietary supplements with the hope that it might be good for you?

Well, according to a study published in an upcoming issue of Psychological Science, a journal of the Association for Psychological Science, there seems to be an interesting asymmetrical relationship between the frequency of dietary supplement use and the health status of individuals. Wen-Bin Chiou of National Sun Yat-Sen University decided to test if frequent use of dietary supplements had ironic consequences for subsequent health-related behaviors after observing a colleague chose an unhealthy meal over an organic meal simply because the colleague had taken a multivitamin earlier in the day.

"After reviewing the literature of the prevalence of dietary supplement use, it seemed to show that use of dietary supplements is increasing, but it does not appear to be correlated with improved public health," says Chiou who conducted the study along with Chao-Chin Yang of National Kaohsiung University of Hospitality and Tourism and Chin-Sheng Wan of Southern Taiwan University.

Two different experiments were conducted using a diverse set of behavioral measures to determine whether the use of dietary supplements would license subsequent health-related behaviors. Participants in Group A were instructed to take a multivitamin and participants in the control group were assigned to take a placebo. However, all the participants actually took placebo pills. The results from the experiments and survey demonstrated that participants who believed they had taken dietary supplements felt invulnerable to health hazards, thus leading them to engage in health-risk behaviors. Specifically, participants in the perceived supplement use group expressed less desire to engage in exercise and more desire to engage in hedonic activities, preferred a buffet over an organic meal (Experiment 1), and walked less to benefit their health (Experiment 2) than the control group.

What does this all mean? Per the results of the study, Chiou says, "People who rely on dietary supplement use for health protection may pay a hidden price, the curse of licensed self-indulgence. After taking dietary supplements in the morning, individuals should diligently monitor whether illusory invulnerability is activated by restored health credentials and subsequently licenses health-risk behaviors." To put it simply, people who take dietary supplements may have the misconception that they are invulnerable to health problems and may make poor decisions when it comes to their health – such as choosing fast food over a healthy and organic meal.

Wednesday, April 20, 2011

Low Sunlight Exposure May Increase Risk of MS

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New research suggests that people who are exposed to low levels of sunlight coupled with a history of having a common virus known as mononucleosis may be at greater odds of developing multiple sclerosis (MS) than those without the virus. The research is published in the April 19, 2011, print issue of Neurology®, the medical journal of the American Academy of Neurology.

“MS is more common at higher latitudes, farther away from the equator,” said George C. Ebers, MD, with the University of Oxford in the United Kingdom and a member of the American Academy of Neurology. “Since the disease has been linked to environmental factors such as low levels of sun exposure and a history of infectious mononucleosis, we wanted to see whether the two together would help explain the variance in the disease across the United Kingdom.”

Infectious mononucleosis is a disease caused by the Epstein-Barr virus, which is a Herpes virus that is extremely common but causes no symptoms in most people. However, when a person contracts the virus as a teenager or adult, it often leads to infectious mononucleosis. The body makes vitamin D when exposed to ultraviolet B (UVB) light.

For the study, researchers looked at all hospital admissions to National Health Service hospitals in England over seven years. Specifically, they identified 56,681 cases of multiple sclerosis and 14,621 cases of infectious mononucleosis. Scientists also looked at NASA data on ultraviolet intensity in England.

The study found that adding the effects of sunlight exposure and mononucleosis together explained 72 percent of the variance in the occurrence of MS across the United Kingdom. Sunlight exposure alone accounted for 61 percent of the variance.

“It’s possible that vitamin D deficiency may lead to an abnormal response to the Epstein-Barr virus,” Ebers said.

He noted that low sunlight exposure in the spring was most strongly associated with MS risk. “Lower levels of UVB in the spring season correspond with peak risk of MS by birth month. More research should be done on whether increasing UVB exposure or using vitamin D supplements and possible treatments or vaccines for the Epstein-Barr virus could lead to fewer cases of MS.”

Link between calcium supplements and heart problems

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Study adds weight to link between calcium supplements and heart problems

Research: Calcium supplements with or without vitamin D and risk of cardiovascular events: Reanalysis of the Women's Health Initiative limited access dataset and meta-analysis

New research published on bmj.com today adds to mounting evidence that calcium supplements increase the risk of cardiovascular events, particularly heart attacks, in older women.

The findings suggest that their use in managing osteoporosis should be re-assessed.

Calcium supplements are often prescribed to older (postmenopausal) women to maintain bone health. Sometimes they are combined with vitamin D, but it's still unclear whether taking calcium supplements, with or without vitamin D, can affect the heart.

The Women's Health Initiative (WHI) study - a seven-year trial of over 36,000 women – found no cardiovascular effect of taking combined calcium and vitamin D supplements, but the majority of participants were already taking personal calcium supplements, which may have obscured any adverse effects.

So a team of researchers, led by Professor Ian Reid at the University of Auckland, re-analysed the WHI results to provide the best current estimate of the effects of calcium supplements, with or without vitamin D, on the risk of cardiovascular events.

They analysed data from 16,718 women who were not taking personal calcium supplements at the start of the trial and found that those allocated to combined calcium and vitamin D supplements were at an increased risk of cardiovascular events, especially heart attack.

By contrast, in women who were taking personal calcium supplements at the start of the trial, combined calcium and vitamin D supplements did not alter their cardiovascular risk.

The authors suspect that the abrupt change in blood calcium levels after taking a supplement causes the adverse effect, rather than it being related to the total amount of calcium consumed. High blood calcium levels are linked to calcification (hardening) of the arteries, which may also help to explain these results.

Further analyses - adding data from 13 other trials, involving 29,000 people altogether - also found consistent increases in the risk of heart attack and stroke associated with taking calcium supplements, with or without vitamin D, leading the authors to conclude that these data justify a reassessment of the use of calcium supplements in older people.

But in an accompanying editorial, Professors Bo Abrahamsen and Opinder Sahota argue that there is insufficient evidence available to support or refute the association.

Because of study limitations, they say "it is not possible to provide reassurance that calcium supplements given with vitamin D do not cause adverse cardiovascular events or to link them with certainty to increased cardiovascular risk. Clearly further studies are needed and the debate remains ongoing."

Childhood music lessons may provide lifelong boost in brain functioning

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Those childhood music lessons could pay off decades later - even for those who no longer play an instrument – by keeping the mind sharper as people age, according to a preliminary study published by the American Psychological Association.

The study recruited 70 healthy adults age 60 to 83 who were divided into groups based on their levels of musical experience. The musicians performed better on several cognitive tests than individuals who had never studied an instrument or learned how to read music. The research findings were published online in the APA journal Neuropsychology.

"Musical activity throughout life may serve as a challenging cognitive exercise, making your brain fitter and more capable of accommodating the challenges of aging," said lead researcher Brenda Hanna-Pladdy, PhD. "Since studying an instrument requires years of practice and learning, it may create alternate connections in the brain that could compensate for cognitive declines as we get older."

While much research has been done on the cognitive benefits of musical activity by children, this is the first study to examine whether those benefits can extend across a lifetime, said Hanna-Pladdy, a clinical neuropsychologist who conducted the study with cognitive psychologist Alicia MacKay, PhD, at the University of Kansas Medical Center.

The three groups of study participants included individuals with no musical training; with one to nine years of musical study; or with at least 10 years of musical training. All of the participants had similar levels of education and fitness and didn't show any evidence of Alzheimer's disease.

All of the musicians were amateurs who began playing an instrument at about 10 years of age. More than half played the piano while approximately a quarter had studied woodwind instruments such as the flute or clarinet. Smaller numbers performed with stringed instruments, percussion or brass instruments.

The high-level musicians who had studied the longest performed the best on the cognitive tests, followed by the low-level musicians and non-musicians, revealing a trend relating to years of musical practice. The high-level musicians had statistically significant higher scores than the non-musicians on cognitive tests relating to visuospatial memory, naming objects and cognitive flexibility, or the brain's ability to adapt to new information.

The brain functions measured by the tests typically decline as the body ages and more dramatically deteriorate in neurodegenerative conditions such as Alzheimer's disease. The results "suggest a strong predictive effect of high musical activity throughout the lifespan on preserved cognitive functioning in advanced age," the study stated.

Half of the high-level musicians still played an instrument at the time of the study, but they didn't perform better on the cognitive tests than the other advanced musicians who had stopped playing years earlier. This suggests that the duration of musical study was more important than whether musicians continued playing at an advanced age, Hanna-Pladdy says.

"Based on previous research and our study results, we believe that both the years of musical participation and the age of acquisition are critical," Hanna-Pladdy says. "There are crucial periods in brain plasticity that enhance learning, which may make it easier to learn a musical instrument before a certain age and thus may have a larger impact on brain development."

The preliminary study was correlational, meaning that the higher cognitive performance of the musicians couldn't be conclusively linked to their years of musical study. Hanna-Pladdy, who has conducted additional studies on the subject, says more research is needed to explore that possible link.

Tuesday, April 19, 2011

A new miracle drug?

While age-related vision loss of catastrophic proportions is predicted in coming decades, rising from 17 million patients today to 55 million by the year 2050, it's possible this catastrophe could be averted and lost vision even restored using molecular medicine.

These are the words of Stuart Richer, OD, PhD, speaking at the 10th annual meeting and International Conference on Recent Trends in Therapeutic Advancement of Free Radical Science, in Chennai, India today.

Dr. Richer says modern medicine is just beginning to evaluate data from the first cases where conventional medical and surgical efforts to restore lost vision had been exhausted and a molecular medicine approach was employed under compassionate use. Even other nutritional therapies including antioxidants were ineffective. Molecular medicine, where small molecules are utilized that can pass through the blood-retinal barrier and which can influence the genetic machinery inside living cells, appears to be very promising, says Dr. Richer.

While this therapy is still unproven, early data indicates larger trials are warranted. The first cases treated under a molecular medicine protocol provide evidence that not only can visual loss in the later years of life be preserved, but lost vision can be restored, particularly among the most severe cases of retinal disease or what is called advanced macular degeneration, says Dr. Richer.

"While I must qualify what I am saying by noting that the severity of retinal disease may improve on its own, I have now documented three consecutive cases where molecular medicine appears to have restored the normal architecture of the human retina and measurably improved visual function that could not be accomplished with conventional care. In one of these cases, vision improved when the patient took an oral a mineral-chelating antioxidant (Longevinex) and deteriorated when the patient ceased taking the antioxidant cocktail, which suggests cause and effect," he says.

Dr. Richer showed an audience of stunned researchers the first photographic slides of their kind – old, damaged retinas that are pocked with aging spots, hemorrhages and poor circulation, becoming more youthful and functional over a relatively short period of time. "We simply need to move to larger human trials where we can determine the reliability and safety of this approach. This can be accomplished within a year, we do not need to wait a decade to conclusively validate this approach," he says.

"The small molecules in the nutriceutical cocktail we used, such as resveratrol, quercetin, rice bran phytate, as provided in commercially-available product called Longevinex, appear to work synergistically and more powerfully in animal studies of heart disease, which is why it was chosen for compassionate use in these individual cases of age-related eye disease," says Dr. Richer.

These cases were deemed unsuitable by a retinal specialist for medical therapy, which consists of injecting an anti-growth factor drug directly into the eye. "There were no remaining options for these patients," says Dr. Richer.

The possibility of using an oral pill rather than injections directly into the eyes is likely to be more welcomed by patients. Such a pill would cost less than a dollar a day. Injectable drug therapy costs around $1000 per injection and six or more injections are often required.

Dr. Richer calls attention to the fact that many senior Americans remain active and drive automobiles but don't fully recognize their vision is fading, and they are developing blind spots, especially if these changes occur in one eye only. Age-related visual decline represents a major road hazard he emphasizes.

"We have growing evidence that molecular medicine can turn mortal heart attacks into non-mortal events and accelerate healing of a damaged heart, and now we are beginning to document that lost vision can be restored, sufficient to help senior adults maintain an active lifestyle, which includes driving an automobile," he says.

Dr. Richer's first case showing molecular medicine improved the vision of an 80-year old man was published in the journal Optometry in 2009.

Dr. Richer cautions patients with existing macular degeneration to be judicious in their use of nutriceuticals, such as resveratrol pills, since very low doses may be ineffective and mega-doses may actually generate free radicals and be toxic. He says the nutriceutical formula chosen for his study, unlike other resveratrol pills, was recently documented to be non-toxic at any tested dose.

"The human retina has tremendous regenerative capacity when molecular medicine is applied," says Dr. Richer. "We are just beginning to appreciate and document the value of small natural molecules that can pass through the blood-retinal barrier and influence the genetic machinery within living cells," he says.

Resveratrol, known as a red wine molecule, exhibits almost magical properties, promoting new blood vessels which speed healing after a heart attack, but doing the exact opposite in the retina, inhibiting the development of new blood vessels which can destroy vision.

Thursday, April 14, 2011

Following cancer prevention guidelines lowers risk of death from cancer, heart disease, all causes

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A study of more than 100,000 men and women over 14 years finds nonsmokers who followed recommendations for cancer prevention had a lower risk of death from cancer, cardiovascular disease, and all-causes. The study appears early online in Cancer Biomarkers, Epidemiology, and Prevention, and was led by American Cancer Society epidemiologists.

Few studies have evaluated the combined impact of following recommended lifestyle behaviors on cancer, cardiovascular disease, and all-cause mortality, and most of those included tobacco avoidance as one of the recommendations. Because eight in ten Americans are never or former smokers, researchers wanted to more clearly understand the impact of other recommended behaviors.

For their study, researchers led by Marji McCullough at the American Cancer Society used diet and lifestyle questionnaires filled out in 1992 and 1993 by 111,966 non-smoking men and women in the Cancer Prevention Study (CPS)-II Nutrition Cohort. The participants were scored on a range from 0 to 8 points to reflect adherence to the American Cancer Society (ACS) cancer prevention guidelines regarding body mass index, physical activity, diet, and alcohol consumption, with 8 points representing adherence to all of the recommendations simultaneously.

After 14 years, men and women with high compliance scores (7, 8) had a 42% lower risk of death compared to those with low scores (0-2). Risk of cardiovascular disease death were 48% lower among men and 58% lower among women, while the risk of cancer death was 30% lower in men and 24% lower in women. Similar associations, albeit not all statistically significant, were observed for never and former smokers.

The researchers conclude that adhering to cancer prevention guidelines for obesity, diet, physical activity, and alcohol consumption is associated with lower risk of death from cancer, cardiovascular disease, and all-causes in non-smokers. They say beyond tobacco avoidance, following other cancer prevention guidelines may substantially lower risk of premature mortality in older adults.

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Wednesday, April 13, 2011

Omega-3 Consumed During Pregnancy Curbs Postpartum Depression Symptoms

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Fish has long been considered in myriad cultures to be "brain food," but only recently has bona fide science begun to support this deep-rooted belief. Researchers now know that the omega-3 fatty acids found in oily fish such as salmon and herring may play a critical role in both development and maintenance of the brain and nerves. Although sufficient amounts of these long-chain fats can be synthesized endogenously by most adults, experts recommend that pregnant women and infants get additional amounts of these compounds from their diets.

This, combined with research suggesting that these fats play a critical role in cognitive and visual development during early life, has prompted much research and product development aimed at pregnant women and newborn infants. Studies have also suggested that higher consumption of certain omega-3 fatty acids may also benefit adult mental health as well -- for instance, as it might relate to lower risk for depression.

Dr. Michelle Price Judge, a faculty member at the University of Connecticut School of Nursing, is keenly interested in how omega-3 fatty acids consumed during pregnancy impact both maternal and infant health. She has demonstrated previously that maternal consumption of docosahexaenoic acid (DHA; a prominent omega-3 fatty acid) during pregnancy gives infants a developmental advantage even 9 months after they are born. These findings prompted her to consider the benefits that DHA could holistically have on the maternal-infant dyad. Specifically, might greater omega-3 fatty acid intake during pregnancy lower risk for postpartum depression, a condition that leads to a multitude of problems including interruptions in maternal-infant attachment and subsequent impairments in later infant development?

As part of the scientific program of the American Society for Nutrition, results from this study will be presented on April 12 at the Experimental Biology 2011 meeting in Washington, DC.

To answer this question, Dr. Judge oversaw a randomized, double-blind, placebo-controlled dietary intervention trial in which 52 pregnant women took either a placebo (corn oil) or a fish oil capsule containing 300 milligrams of DHA 5 days each week from 24-40 weeks of pregnancy. This is the amount a woman would consume if she ate about ½ serving of salmon. It is noteworthy that dietary DHA intake during pregnancy has been estimated to be 50-70 milligrams of DHA daily: a mere fraction of the 200 milligrams daily that is considered optimal during pregnancy by most experts. Using the Postpartum Depression Screening Scale developed by her colleague and coauthor Dr. Cheryl Beck, Judge was able to categorize postpartum women as having negligible depressive symptoms, significant symptoms of postpartum depression, or being "positive" for this condition. The Postpartum Depression Screening Scale also assisted the research team in discerning between several symptoms specific to the disorder including sleeping/eating disturbances, anxiety, emotional liability, confusion, loss of self, guilt, and thoughts of suicide.

Although the study did not have enough women to investigate if fish oil consumption resulted in a lower incidence of diagnosable postpartum depression, women in the treatment group had significantly lower total Postpartum Depression Screening Scale scores, with significantly fewer symptoms common to postpartum depression. For example, compared to those in the control group, women in the fish oil group were less likely to report symptoms related to anxiety and loss of self.

Judge and coworkers concluded "DHA consumption during pregnancy -- at levels that are reasonably attained from foods -- has the potential to decrease symptoms of postpartum depression." Why is this important? For starters, some experts estimate that postpartum depression affects a whopping 25% of new mothers. And healthcare providers agree that this condition can have devastating consequences, not only for the women experiencing it but also for their children and family.

The bottom line? Although larger-scale intervention studies will be needed to better understand the mechanisms and magnitude by which fish oil consumption can improve postpartum mental health, women would be wise to eat at least a serving of high-omega-3 fish 2-3 days per week. Although fish oil supplements may be more acceptable to some women, the real thing is clearly the more nutritious option as a serving of fish is also protein- and mineral-rich. Clearly, fish as a "brain food" is gaining the nod from not only from the general public, but scientists as well.

Vegetarians may be at lower risk of heart disease, diabetes and stroke

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Vegetarians experience a 36 percent lower prevalence of metabolic syndrome than non-vegetarians, suggests new research from Loma Linda University published in the journal Diabetes Care. Because metabolic syndrome can be a precursor to heart disease, diabetes, and stroke, the findings indicate vegetarians may be at lower risk of developing these conditions.

Metabolic syndrome is defined as exhibiting at least three out of five total risk factors: high blood pressure, elevated HDL cholesterol, high glucose levels, elevated triglycerides, and an unhealthy waist circumference. The Loma Linda University study found that while 25 percent of vegetarians had metabolic syndrome, the number significantly rises to 37 percent for semi-vegetarians and 39 percent for non-vegetarians. The results hold up when adjusted for factors such as age, gender, race, physical activity, calories consumed, smoking, and alcohol intake.

"In view of the high rate of metabolic syndrome in the United States and its deleterious health effects, we wanted to examine lifestyle patterns that could be effective in the prevention and possible treatment of this disorder," says lead researcher Nico S. Rizzo, PhD.

"I was not sure if there would be a significant difference between vegetarians and non-vegetarians, and I was surprised by just how much the numbers contrast," he continues. "It indicates that lifestyle factors such as diet can be important in the prevention of metabolic syndrome."

The study examined more than 700 adults randomly sampled from Loma Linda University's Adventist Health Study 2, a long-term study of the lifestyle and health of almost 100,000 Seventh-day Adventist Christians across the United States and Canada.

Thirty-five percent of the subjects in this smaller sub-study were vegetarian. On average, the vegetarians and semi-vegetarians were three years older than non-vegetarians. Despite their slightly older age, vegetarians had lower triglycerides, glucose levels, blood pressure, waist circumference, and body mass index (BMI). Semi-vegetarians also had a significantly lower BMI and waist circumference compared to those who ate meat more regularly.

"This work again shows that diet improves many of the main cardiovascular risk factors that are part of metabolic syndrome," says Gary Fraser, MD, PhD, principal investigator of Adventist Health Study 2. "Trending toward a plant-based diet is a sensible choice."

Dietary Supplement Use Among U.S. Adults Has Increased

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This report provides estimates of dietary supplement use for specific population groups over time. In addition to overall use of dietary supplements, this report focuses on estimates for specific nutrients consumed through dietary supplement use.

Key findings

* Use of dietary supplements is common among the U.S. adult population. Over 40% used supplements in 1988–1994, and over one-half in 2003–2006.
* Multivitamins/multiminerals are the most commonly used dietary supplements, with approximately 40% of men and women reporting use during 2003–2006.
* Use of supplemental calcium increased from 28% during 1988–1994 to 61% during 2003–2006 among women aged 60 and over.
* Use of supplements containing folic acid among women aged 20–39 did not increase since 1988–1994. In 2003–2006, 34% of women aged 20–39 used a dietary supplement containing folic acid.
* Use of dietary supplements containing vitamin D increased from 1988–1994 through 1999–2002 for men and women in most age groups.

Jon's Health Tips - Latest Health Research

Lots of research in the last two weeks, mostly reinforcing what I already know is good for me and I make part of my regular regimen.

1. Exercise

A. Moderate exercise improves brain blood flow



A steady, healthy flow of blood to the brain achieves two things. First, the blood brings oxygen, glucose and other nutrients to the brain, which are vital for the brain's health. Second, the blood washes away brain metabolic wastes such as amyloid-beta protein released into the brain's blood vessels. Amyloid-beta protein has been implicated in the development of Alzheimer's disease.




B. Brief Intense Exercise Better Than Endurance Training for Preventing Cardiovascular Disease

C. Exercise may prevent stress on telomeres, a measure of cell health

D. Older and stronger: Progressive resistance training

2. Apples

'Apple a day' advice rooted in science



Apples are truly a "miracle fruit" that convey benefits beyond fiber content. Apple pectin and polyphenols in apple improve lipid metabolism and lower the production of pro-inflammatory molecules.

The results surprised Dr. Arjmandi, who stated that "incredible changes in the apple-eating women happened by 6 months- they experienced a 23% decrease in LDL cholesterol," which is known as the "bad cholesterol." The daily apple consumption also led to a lowering of lipid hydroperoxide levels and C-reactive protein in those women.

"I never expected apple consumption to reduce bad cholesterol to this extent while increasing HDL cholesterol or good cholesterol by about 4%," Arjmandi said

"Reducing body weight is an added benefit to daily apple intake" he said. Part of the reason for the weight loss could be the fruit's pectin, which is known to have a satiety effect.




3. Alcohol

A. Drinking alcohol primes certain areas of our brain to learn and remember better, says a new study.

and

B. More Alcohol Consumption Over 40 = Less Death

but:

C. Excess Alcohol Consumption Causes Cancer?



A substantial number of cancer cases in both men and women can be attributed to excess alcohol consumption, according to a study published online April 7.




(I’m not impressed with this study.)

4. Blueberries

Blueberries may inhibit development of fat cells




The benefits of blueberry consumption have been demonstrated in several nutrition studies, more specifically the cardio-protective benefits derived from their high polyphenol content. Blueberries have shown potential to have a positive effect on everything from aging to metabolic syndrome. Recently, a researcher showed that blueberries polyphenols fight adipogenesis, which is the development of fat cells, and induce lipolysis, which is the breakdown of lipids/fat.





5 Green tea

Green tea enhances bone health and reduces inflammation



Dozens of epidemiological (observational) studies have shown that people who consume the highest levels of green tea polyphenols (GTP) tend to have lower risks of several chronic degenerative diseases such as cardiovascular disease and osteoporosis. These findings have been followed up with animal studies, including some conducted by Shen, suggesting that the mechanism behind this correlation may have to do with lowering chronic levels of inflammation.

In Shen's most recent research, she found that green tea enhances bone health and reduces inflammation in postmenopausal women.




7. Vitamin D

A. Vitamin D may help reduce heart risk in African-Americans



Supplementation of 60,000 IU monthly improves vascular function

In recent years supplementation with Vitamin D has been shown to reduce the risk of cardiovascular disease (CVD) in people who are deficient in the vitamin. Now new research indicates that supplementation with the "sunshine vitamin" may be particularly beneficial for overweight African-American adults, a population at increased risk for both CVD and Vitamin D deficiency.




And:

B. Vitamin D Levels Linked With Health of Blood Vessels

But:

C. Use of vitamin D supplementation is clearly tricky




For example, in the colon, vitamin D seems to reduce the risk of cancer development, but it may not have any effect on later stage colon cancer. There is also concern that vitamin D may increase the risk of prostate, esophagus and pancreatic cancer. In work she has conducted in endometrial cancer, Hilakivi-Clarke found that although vitamin D was not beneficial in lean mice, in obese animals it reverses both early and advanced stages of the cancer.




8. Orange juice

Drinking 100 percent fruit juice may offer disease-fighting benefits



Highlights from a new report summarizing recent research on the potential benefits of fruit juice suggest a positive association between intake of 100 percent juice and reduced risk for several chronic diseases, including cancer, markers for cardiovascular disease and cognitive decline.

Among the fruit juices included in the review, consumption of apple, citrus, cranberry, grape, and pomegranate juices all showed beneficial effects. Markers of improved health ranged from reductions in urinary tract infections (cranberry) to improvements in age-related cognitive decline (grape and apple) to reduced risk of prostate (pomegranate) and respiratory and digestive (orange, grapefruit) cancers. Additionally, intake of all juices was linked to heightened antioxidant activity.




9. Nuts

Pistachios deliver weight management support, heart health benefits


10. Strawberries

Strawberries may slow precancerous growth in the esophagus

11. Statins

Pneumonia Death Rate Lower Among People Who Take Statins

12. Aspirin

Aspirin may lower the risk of pancreatic cancer



The use of aspirin at least once per month is associated with a significant decrease in pancreatic cancer risk.




I’m not ready to take up this heart healthy activity more than once a year, however:

Routine periodic fasting is good for your health



Fasting found to reduce cardiac risk factors, such as triglycerides, weight, and blood sugar levels




Or add much of this to my diet:

Maple syrup's health benefits



Pure maple syrup may pack similar health benefits to those found in berries, tea, red wine and flax seed




And, apparently, I’m doomed:

Frequent Shopping Prolongs Life, Study Suggests:



Those who shopped daily were 27% less likely to die, with male daily shoppers 28% less likely to die, compared with female shoppers who were 23% less likely to die.




Other articles of interest:
Caffeine and diabetes -- helpful or harmful?
Got a craving for fast food? Skip the coffee
Vegans' elevated heart risk requires omega-3s and B12
Vitamins & Supplements: Safety First
New Analysis of Essential Mineral Selenium
Eat candy without adverse health effects
3 square meals a day paired with lean protein help people feel full during weight loss

Tuesday, April 12, 2011

New Analysis of Essential Mineral Selenium

An analysis of the essential mineral selenium suggests that adequate intake of essential mineral selenium could help to prevent age-related conditions such as immune dysfunction, cardiovascular disease, and cancer. Selenium is present in dietary plants if the soil has adequate amounts, which is generally true in the U.S., but not in parts of China, Russia, and most of Western Europe.

The analysis was designed to test Dr. Ames’ “triage” theory that provides a new basis for determining the optimum intake of individual vitamins and minerals by measuring long-term insidious damage associated with aging, and that has major implications for preventive medicine. The selenium analysis strongly supports the theory and is published in the March 2011 issue of the The Federation of American Societies for Experimental Biology (FASEB) Journal. The analysis provides a consistent scientific basis for establishing optimum vitamin and mineral intakes, which will add credence to recommendations for improving inadequacies in micronutrient intake of the American diet.

Dr. Ames proposed the triage theory in 2006 (2) to explain numerous observations from his own lab and the scientific literature. The triage theory explains why diseases associated with aging (and the pace of aging itself) may be unintended consequences of mechanisms developed during evolution to protect metabolic processes against episodic vitamin and mineral shortages. Dr. Ames reasoned that these mechanisms are focused on preserving vitamin and mineral-dependent functions required for animals to survive for reproduction, at the expense of other functions required to sustain long-term health -- not a priority for evolution. As a result, Dr. Ames proposed that modest shortages in vitamin and mineral (against which (“essential”) functions are protected) lead to insidious metabolic damage in so-called “less critical functions” that over time accelerates aging and may lead to diseases of aging such as cancer, heart disease, and dementia. If correct, the triage theory has widespread implications for public health because modest vitamin and mineral deficiencies are quite common. It also suggests a new scientifically based and consistent strategy for establishing optimal vitamin and mineral intake standards, and it provides a research strategy to uncover early biomarkers of chronic disease.

This selenium analysis is the second in a series of literature-based studies conducted by Drs. McCann and Ames to test the basic premises of the triage theory by constructing triage-based biological profiles of individual vitamin and minerals. A previous analysis of published evidence on vitamin K (3), also strongly supported the theory.

The new analysis reviews about half of the 25 known mammalian selenoproteins; all of those with mouse knockout or human mutant phenotypes that could be used as criteria for a classification of “essential” or “nonessential”. On modest selenium deficiency, nonessential selenoprotein activities and concentrations are preferentially lost. Mechanisms include the requirement of a special form of tRNA sensitive to selenium deficiency for translation of nonessential selenoprotein mRNAs. The same set of age-related diseases and conditions, including cancer, heart disease, and immune dysfunction, are prospectively associated with modest selenium deficiency and also with genetic dysfunction of nonessential selenoproteins, suggesting that selenium deficiency could be a causal factor, a possibility strengthened by mechanistic evidence. Modest selenium deficiency is common in many parts of the world; optimal intake could prevent future disease, but as too much selenium is quite toxic, don’t overdo the supplementation.

The analysis of Drs. McCann and Ames has wider implications. If results for vitamin K and selenium can be generalized to other vitamin and minerals, as the triage theory proposes, not only experts aiming to set intake recommendations for optimal function, but scientists seeking mechanistic triggers leading to diseases of aging should look among micronutrient-dependent functions that have escaped evolutionary protection from deficiency. A brief summary of the triage theory and the vitamin K analysis has been published (4).

References:

1. McCann JM & Ames BN (2011) Adaptive dysfunction of selenoproteins from the perspective of the triage theory: Why modest selenium deficiency may increase risk of diseases of aging. FASEB J, 25: in press
2. Ames, B (2006) Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage. Proc. Natl. Acad. Sciences, U.S.A., 103:17589-94.
3. McCann JM and Ames BN (2009) Vitamin K, an example of triage theory: is micronutrient inadequacy linked to diseases of aging? Am J Clin Nutr. 90: 889-907.
4. Ames, BN (2010) Prevention of mutation, cancer, and other age-associated diseases by optimizing micronutrient intake. Journal of Nucleic Acids Special Issue: DNA Damage, Mutagenesis, and DNA Repair. doi:10.4061/2010/725071.

Moderate exercise improves brain blood flow

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Brisk walking several times per week bestows benefits in just 3 months


Research conducted at Texas Health Presbyterian Hospital's Institute for Exercise and Environmental Medicine in Dallas suggests that it's never too late for women to reap the benefits of moderate aerobic exercise. In a 3-month study of 16 women age 60 and older, brisk walking for 30-50 minutes three or four times per week improved blood flow through to the brain as much as 15%.

Rong Zhang, the lead researcher in the study, will discuss the team's findings in a presentation titled, "Aerobic exercise training increases brain perfusion in elderly women" at the Experimental Biology meeting (EB 2011), being held April 9-13, 2011 at the Walter E. Washington Convention Center, Washington, DC.

The Study

At the beginning of the study, the researchers used Doppler ultrasonography to measure blood flow in the women's internal carotid arteries, which are located in the neck and supply the brain with necessary glucose and oxygen-rich blood. After assessing the women's physical health and maximal oxygen consumption (VO2 max), which is the body's maximum capacity to transport and use oxygen during exercise, the team tailored training programs for each woman according to her fitness level.

Training started at a base pace of 50-60% of the participants' VO2 max for 30 minutes per session, three times per week. By the third month, the team had increased the sessions to 50 minutes each, four times per week, and added two more sessions at 70-80% of the women's VO2 max for 30 minutes.

At study's end, the team measured blood flow in the women's carotid arteries again and found that cerebral blood flow increased an average of 15% and 11% in the women's left and right internal carotid arteries, respectively. The women's VO2 max increased roughly 13%, their blood pressure dropped an average of 4%, and their heart rates decreased approximately 5%.

According to Dr. Zhang, the results provide insight into how vascular health affects brain health. "There are many studies that suggest that exercise improves brain function in older adults, but we don't know exactly why the brain improves. Our study indicates it might be tied to an improvement in the supply of blood flow to the brain."

Blood Flow and the Brain


A steady, healthy flow of blood to the brain achieves two things. First, the blood brings oxygen, glucose and other nutrients to the brain, which are vital for the brain's health. Second, the blood washes away brain metabolic wastes such as amyloid-beta protein released into the brain's blood vessels. Amyloid-beta protein has been implicated in the development of Alzheimer's disease.

Whether the increased blood flow to the brain improves learning and reasoning has yet to be determined, says Dr. Zhang. "I don't have the data to suggest a correlation between brain perfusion and cognitive function, but this is something we eventually will see after this study is completed," he says. "We do know there is strong evidence to suggest that cardiovascular risk is tied to the risk for Alzheimer's disease. We want to see how we can fight that."

Dr. Zhang stresses the importance of the finding that improvement in brain blood flow is possible in one's senior years. "We often start to see a decline in brain perfusion and cognitive function in the 60s and 70s. That's when the downward trajectory starts. We want to see how much we can do to reverse or delay that process."

'Apple a day' advice rooted in science

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Everyone has heard the old adage, "an apple a day keeps the doctor away." We all know we should eat more fruit. But why apples? Do they contain specific benefits?

According to Dr. Bahram H. Arjmandi, PhD, RD, Margaret A. Sitton Professor and Chair, Department of Nutrition, Food and Exercise Sciences at The Florida State University, apples are truly a "miracle fruit" that convey benefits beyond fiber content. Animal studies have shown that apple pectin and polyphenols in apple improve lipid metabolism and lower the production of pro-inflammatory molecules. Arjmandi's most recent research is the first to evaluate the long-term cardioprotective effects of daily consumption of apple in postmenopausal women. The results of this USDA-funded study will be presented at Experimental Biology 2011 on Tuesday, April 12, at 12:45 pm in Washington, DC.

This study randomly assigned 160 women ages 45-65 to one of two dietary intervention groups: one received dried apples daily (75g/day for 1 year) and the other group ate dried prunes every day for a year. Blood samples were taken at 3, 6 and 12-months. The results surprised Dr. Arjmandi, who stated that "incredible changes in the apple-eating women happened by 6 months- they experienced a 23% decrease in LDL cholesterol," which is known as the "bad cholesterol." The daily apple consumption also led to a lowering of lipid hydroperoxide levels and C-reactive protein in those women.

"I never expected apple consumption to reduce bad cholesterol to this extent while increasing HDL cholesterol or good cholesterol by about 4%," Arjmandi said. Yet another advantage is that the extra 240 calories per day consumed from the dried apple did not lead to weight gain in the women; in fact, they lost on average 3.3 lbs. "Reducing body weight is an added benefit to daily apple intake" he said. Part of the reason for the weight loss could be the fruit's pectin, which is known to have a satiety effect. The next step in confirming the results of this study is a multi-investigator nationwide study.

There is frequently some truth behind our common expressions, and in the case of 'an apple a day,' Dr. Arjmandi has shown that nutrition science backs up the expression. "Everyone can benefit from consuming apples," he said.

Alcohol helps the brain remember, says new study

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Drinking alcohol primes certain areas of our brain to learn and remember better, says a new study from the Waggoner Center for Alcohol and Addiction Research at The University of Texas at Austin.

The common view that drinking is bad for learning and memory isn't wrong, says neurobiologist Hitoshi Morikawa, but it highlights only one side of what ethanol consumption does to the brain.

"Usually, when we talk about learning and memory, we're talking about conscious memory," says Morikawa, whose results were published last month in The Journal of Neuroscience. "Alcohol diminishes our ability to hold on to pieces of information like your colleague's name, or the definition of a word, or where you parked your car this morning. But our subconscious is learning and remembering too, and alcohol may actually increase our capacity to learn, or 'conditionability,' at that level."

Morikawa's study, which found that repeated ethanol exposure enhances synaptic plasticity in a key area in the brain, is further evidence toward an emerging consensus in the neuroscience community that drug and alcohol addiction is fundamentally a learning and memory disorder.

When we drink alcohol (or shoot up heroin, or snort cocaine, or take methamphetamines), our subconscious is learning to consume more. But it doesn't stop there. We become more receptive to forming subsconscious memories and habits with respect to food, music, even people and social situations.

In an important sense, says Morikawa, alcoholics aren't addicted to the experience of pleasure or relief they get from drinking alcohol. They're addicted to the constellation of environmental, behavioral and physiological cues that are reinforced when alcohol triggers the release of dopamine in the brain.

"People commonly think of dopamine as a happy transmitter, or a pleasure transmitter, but more accurately it's a learning transmitter," says Morikawa. "It strengthens those synapses that are active when dopamine is released."

Alcohol, in this model, is the enabler. It hijacks the dopaminergic system, and it tells our brain that what we're doing at that moment is rewarding (and thus worth repeating).

Among the things we learn is that drinking alcohol is rewarding. We also learn that going to the bar, chatting with friends, eating certain foods and listening to certain kinds of music are rewarding. The more often we do these things while drinking, and the more dopamine that gets released, the more "potentiated" the various synapses become and the more we crave the set of experiences and associations that orbit around the alcohol use.

Morikawa's long-term hope is that by understanding the neurobiological underpinnings of addiction better, he can develop anti-addiction drugs that would weaken, rather than strengthen, the key synapses. And if he can do that, he would be able to erase the subconscious memory of addiction.

"We're talking about de-wiring things," says Morikawa. "It's kind of scary because it has the potential to be a mind controlling substance. Our goal, though, is to reverse the mind controlling aspects of addictive drugs."

Monday, April 11, 2011

Blueberries may inhibit development of fat cells

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The benefits of blueberry consumption have been demonstrated in several nutrition studies, more specifically the cardio-protective benefits derived from their high polyphenol content. Blueberries have shown potential to have a positive effect on everything from aging to metabolic syndrome. Recently, a researcher from Texas Woman's University (TWU) in Denton, TX, examined whether blueberries could play a role in reducing one of the world's greatest health challenges: obesity. Shiwani Moghe, MS, a graduate student at TWU, decided to evaluate whether blueberry polyphenols play a role in adipocyte differentiation, the process in which a relatively unspecialized cell acquires specialized features of an adipocyte, an animal connective tissue cell specialized for the synthesis and storage of fat. Plant polyphenols have been shown to fight adipogenesis, which is the development of fat cells, and induce lipolysis, which is the breakdown of lipids/fat. Moghe will present her research at the Experimental Biology 2011 meeting for the American Society for Nutrition on Sunday, April 10, at 12:45 pm.

"I wanted to see if using blueberry polyphenols could inhibit obesity at a molecular stage," said Moghe. The study was performed in tissue cultures taken from mice. The polyphenols showed a dose-dependent suppression of adipocyte differentiation. The lipid content in the control group was significantly higher than the content of the tissue given three doses of blueberry polyphenols. The highest dose of blueberry polyphenols yielded a 73% decrease in lipids; the lowest dose showed a 27% decrease.

"We still need to test this dose in humans, to make sure there are no adverse effects, and to see if the doses are as effective. This is a burgeoning area of research. Determining the best dose for humans will be important," said Moghe. "The promise is there for blueberries to help reduce adipose tissue from forming in the body."

These preliminary results contribute more items to the laundry list of benefits related to blueberries, which have already been shown to mitigate health conditions like cardiovascular disease and metabolic syndrome.

Green tea enhances bone health and reduces inflammation

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Tea has for generations been an integral infusion worldwide, carrying both epicurean and economic significance. But, does it impart honest-to-goodness health benefits? In other words, is its persistence in the human diet perhaps coincident with enhanced quality (or quantity) of life?

Dr. Chwan-Li (Leslie) Shen, an associate professor and a researcher at the Laura W. Bush Institute for Women's Health at the Texas Tech University Health Sciences Center, is convinced that the answer to this question is a resounding yes – especially if the tea is of the "green" variety. Green tea, historically consumed in the Orient and now an international mainstay, is chock full of compounds called polyphenols known for their potent antioxidant activity. Dozens of epidemiological (observational) studies have shown that people who consume the highest levels of green tea polyphenols (GTP) tend to have lower risks of several chronic degenerative diseases such as cardiovascular disease and osteoporosis. These findings have been followed up with animal studies, including some conducted by Shen, suggesting that the mechanism behind this correlation may have to do with lowering chronic levels of inflammation.

Originally from Taiwan, Dr. Shen has now spent over 2 decades studying how and why some Eastern lifestyle norms (such as drinking green tea) might be beneficial for Westerners as well. For instance, she has developed an animal model (the ovariectomized, middle-aged female rat). With this model Dr. Shen and her team can effectively study the effects of green tea consumption on protection against breakdown of the bone's microarchitecture. In humans, this can lead to osteoporosis, a condition common to older women. It is Dr Shen's hope that what she learns from her animal models might also be applicable to postmenopausal women.

In Shen's most recent research, she focused on postmenopausal women and investigated the potential for green tea to work synergistically with tai chi – a traditional Chinese form of moderately intense aerobic fitness activity grounded in mind-body philosophy – in enhancing bone strength. The results of this work, which was funded by the National Institutes of Health/National Center for Complementary and Alternative Medicine, will be presented as a poster at the Experimental Biology meetings on April 10. Carried out as a double-blind, placebo-controlled, intervention trial (the "holy grail" of scientific studies), this experiment involved 171 postmenopausal women (mean age: ~57 y) who had weak bones but not full-fledged osteoporosis. Subjects were divided into 4 groups:

Placebo: starch pill (placebo) and no tai chi
GTP: green tea polyphenols (500 mg/day) and no tai chi
Placebo+TC: starch pill and tai chi (3 times/week)
GTP+TC: green tea polyphenols and tai chi
The study lasted for 6 months, during which time blood and urine samples were collected and muscle strength assessed.

The results show that consumption of GTP (at a level equivalent to about 4-6 cups of steeped green tea daily) and participation in tai chi independently enhanced markers of bone health by 3 and 6 months, respectively. A similar effect was found for muscle strength at the 6-month time point. Participants taking tai chi classes also reported significant beneficial effects in quality of life in terms of improving their emotional and mental health. Perhaps most remarkable, however, was the substantial effect that both GTP and tai chi had on biological markers of oxidative stress. Because oxidative stress is a main precursor to inflammation, this finding suggests that green tea and tai chi may help reduce the underlying etiology of not only osteoporosis, but other inflammatory diseases as well.

Dr. Shen and colleagues concluded that there is a "favorable effect of modest green tea consumption on bone remodeling in this pre-osteoporotic population" and hope to soon complete a more long-term study utilizing more technically savvy measures of bone density.

Vitamin D may help reduce heart risk in African-Americans

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Supplementation of 60,000 IU monthly improves vascular function


In recent years supplementation with Vitamin D has been shown to reduce the risk of cardiovascular disease (CVD) in people who are deficient in the vitamin. Now new research from the Georgia Prevention Institute at Georgia Health Sciences University in Augusta indicates that supplementation with the "sunshine vitamin" may be particularly beneficial for overweight African-American adults, a population at increased risk for both CVD and Vitamin D deficiency.

According to Ryan A. Harris, PhD, assistant professor, the Georgia team's research suggests that Vitamin D supplementation cut the cardiovascular risk by improving the health and function of vascular endothelial cells, cells that line the inside of blood vessels. He will discuss the team's findings at the Experimental Biology 2011 meeting (EB 2011), being held April 9-13, 2011 at the Walter E. Washington Convention Center in Washington, DC. The presentation is entitled "Vitamin D Improves Flow-Mediated Dilation in African American Adults."

A Population at Risk

African-Americans as a group have multiple risk factors for CVD. They are more likely than people of other races to develop type 2 diabetes, a known contributor to CVD, and when they develop high blood pressure it tends to be more severe than that of other groups. African-Americans also have a greater risk of developing Vitamin D deficiency: The pigmentation in their skin inhibits their skin cells' ability to produce Vitamin D in response to exposure to sunlight.

The Study

In the study, 45 overweight African-American adults who were separated into two groups. (Overweight participants were chosen because carrying extra weight has been linked to inflammation in blood vessels, another risk for CVD.) One group, the treatment group, received 60,000 IU of Vitamin D in a single dose every 4 weeks for 16 weeks. The second group, the placebo group, received dummy pills. Although 60,000 IU seems like a high dose, Vitamin D has a half life of approximately 3 weeks, which means that half the dose is still in the body 3 weeks after it is taken. Given the time it takes the body to clear Vitamin D, a dose of 60,000 IU equals about 2,000 IU a day.

"We could have used daily dosing, but we knew compliance would be better with monthly dosing. One dose a month is easier than taking two pills a day," says Dr. Harris. He notes that participants reported no side effects.

At the beginning of the study, the researchers used an inflatable cuff to increase blood flow in the brachial arteries of the participants' arms, then used ultrasound to measure the arteries flow-mediated dilation. Flow-mediated dilation occurs when blood vessels dilate, or open up, in response to increased blood flow, which allows the blood to flow more freely. Vascular endothelial cells play a role in blood vessel dilation; endothelial cell dysfunction is considered to be the first sign of atherosclerosis, or "hardening of the arteries." When there is endothelial dysfunction, the blood vessels do not dilate as much and the heart has to pump harder to push blood through the vessels.

After 16 weeks, the researchers measured the participants' flow-mediated dilation again and found that flow-mediated dilation had improved in the treatment group, but not in the placebo group.

"This points to a beneficial effect of Vitamin D supplementation on endothelial cell function," says Dr. Harris. He adds that this is good news for African-Americans, given their risks for CVD. "If you're deficient in Vitamin D and you take supplements, you have a good probability of increasing endothelial function and therefore decreasing the risk of cardiovascular disease."

Exactly how Vitamin D works on the endothelial cells is the "million-dollar question" Dr. Harris says. "Vitamin D interacts with a lot of different systems in the body. It may decrease inflammation, which is better for endothelial function."

He added that more research is needed to discover the long-term effects of supplementation.

Drinking 100 percent fruit juice may offer disease-fighting benefits

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Fruit juice linked to reduced risk of cancer, improved markers of heart health and increased antioxidant activity


Drinking 100 percent fruit juices could have protective health benefits similar to those of whole fruits, according to research presented in a literature review yesterday at the 2011 Experimental Biology (EB) meeting.

Highlights from a new report summarizing recent research on the potential benefits of fruit juice suggest a positive association between intake of 100 percent juice and reduced risk for several chronic diseases, including cancer, markers for cardiovascular disease and cognitive decline.

"While it is universally accepted that fruit and vegetable intake is protective, there is not a clear consensus about the benefits of consuming the juices that are extracted from them," said the review's author, Dianne Hyson, PhD, MS, RD. "An analysis of the scientific evidence suggests that 100 percent fruit juices retain important bioactive components that may promote good health and aid in disease prevention."

Among the fruit juices included in the review, consumption of apple, citrus, cranberry, grape, and pomegranate juices all showed beneficial effects. Markers of improved health ranged from reductions in urinary tract infections (cranberry) to improvements in age-related cognitive decline (grape and apple) to reduced risk of prostate (pomegranate) and respiratory and digestive (orange, grapefruit) cancers. Additionally, intake of all juices was linked to heightened antioxidant activity.

Research examined in the review, which was completed at the University of California - Davis, included a range of study types, from in vitro to clinical trials (60 papers total), all published in 2005 or later.

Pistachios deliver weight management support, heart health benefits

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New USDA study: Fat found in pistachios may not be readily absorbed by the body


In a first-of-its-kind study with nuts, randomized controlled-feeding research conducted by the Agricultural Research Service (ARS) of the United States Department of Agriculture (USDA) found that fat in pistachios may not be completely absorbed by the body. The findings indicate that pistachios may actually contain fewer calories per serving than originally thought – further validating pistachios as one of the lowest calorie nuts with 160 calories per 30 gram serving (approximately 1 ounce). The study was presented today at the Experimental Biology conference in Washington, D.C.

The research measured the energy value of pistachios by feeding 16 healthy adults the nuts as part of a controlled diet and calculating the energy value from differences in energy excretion during the dietary treatment timeframe. The resulting energy value of one 30 gram serving of pistachios was 5.9 percent less than previous calculations.

"Existing scientific research indicates that fat from nuts is poorly absorbed through the gastrointestinal tract," said lead ARS researcher David J. Baer, Ph.D., Supervisory Research Physiologist with the Beltsville Human Nutrition Research Center. "This study confirms that the fat from pistachio nuts, specifically, is not completely digested or absorbed, resulting in a lower energy value."

Additional data from this study presented at Experimental Biology reinforced the heart-health benefits of pistachios. The ARS researchers found that when healthy individuals included 1.5 and 3 ounces of pistachios into their typical American diet, cardio-supportive results were shown.

Pistachios Deliver Weight Management Support Benefits

The new data demonstrating the potential calorie savings of pistachios builds on previous research showing that pistachios are a weight-wise snack. According to researchers at the University of California – Los Angeles, choosing to snack on pistachios rather than pretzels not only supports body mass index (BMI) goals, but can support heart health, too.

In a 12-week randomized study, 52 overweight and obese subjects were placed on a 500-calorie deficit diet and assigned to either a pistachio snack (about 75 pistachios providing 240 calories) or a pretzel snack group (two-ounces of pretzels providing 220 calories). The results showed that the pistachio group had better success with supporting their BMI goals compared to the pretzel group, showing pistachios can be included in a healthy diet, even for those managing their weight.

Additionally, pistachios – also known as the "Skinny Nut" – are shown to be a "mindful snack" in terms of taking longer to eat and requiring the snacker to slow down and be more conscious of what has been consumed. According to behavioral eating expert, James Painter, Ph.D., R.D., Chair of the School of Family and Consumer Sciences at Eastern Illinois University, "Our research shows in-shell snackers eat 41-percent fewer calories than those who snack on shelled nuts. We also found that in-shell pistachios offer a visual cue to help reduce intake. When leftover shells are cleared immediately, snackers eat up to 22 percent more compared to leaving left over shells as a reminder of consumption. "

Pistachios are also a good source of fiber and protein. Providing about 49 kernels per 30 grams (approximately 1 ounce) serving, pistachios offer the most nuts per serving when compared to other popular snack nuts – comparatively, almonds have 23 in a serving, walnuts 14 halves and cashews, 18.

Frequent Shopping Prolongs Life, Study Suggests

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A spot of regular retail therapy really does seem to help people live longer, suggests research published online in the Journal of Epidemiology and Community Health.

And it seems to benefit older men the most, the findings show.

The authors base their findings on almost 1,850 elderly (65+) Taiwanese people who were living independently at home, and included in the nationally representative Elderly Nutrition and Health Survey in Taiwan (NAHSIT Elderly), carried out in 1999-2000.

Participants were asked how often they went shopping, with options ranging from "never" to "every day."

Intellectual and physical capacities were measured using validated questionnaires, and age, gender, education, ethnicity, financial and employment status, lifestyle factors and the prevalence of long term conditions were also factored in.

The researchers then tracked how long each of the participants lived by linking individuals to national death registration data between 1999 and 2008.

Nearly half (48%) of the participants never or infrequently shopped during the week, and around one in four (22%) shopped between two and four times a week. A further 17% shopped every day, and the remainder shopped just once a week.

Almost two thirds of respondents were under the age of 75. Just over half (54%) were men. Most had a healthy lifestyle and three out of four were financially self sufficient. Almost two thirds (60%) had up to two long term conditions.

Those who went shopping more than once a week tended to be at the younger end of the age spectrum, and male. They also tended to be smokers and drinkers, have better physical and mental health, take regular exercise and have a network of dinner companions.

The researchers used different approaches to take account of physical limitations and cognitive impairment, but even so, those who shopped daily lived longer than those who shopped less frequently.

Those who shopped daily were 27% less likely to die, with male daily shoppers 28% less likely to die, compared with female shoppers who were 23% less likely to die.

The authors acknowledge that shopping could be a surrogate for good health to begin with, but suggest that shopping itself may improve health, by ensuring a good supply of food, to maintain a healthy diet, for example.

Frequent shopping among the elderly may not always be about buying things, but about seeking companionship or taking exercise, which is easier to do than more formal exercise that usually requires motivation, they say.

The conventional view of health promotion focuses on physical activity, but engaging in social and economic activities in later life may also contribute to better health, they add.

"Shopping captures several dimensions of personal wellbeing, health, and security as well as contributing to the community's cohesiveness and economy, and may represent or actually confer increased longevity," they conclude.