News Briefs – June 2009

VITAMIN D BOOSTS BRAIN POWER?

Increased levels of vitamin D – synthesized in the skin following sun exposure and found in certain foods, such as oily fish, as well as supplements – are linked to improved cognitive function in middle-aged and older men, says a new study.
University of Manchester scientists, in collaboration with colleagues from other European centres, compared the cognitive performance of more than 3,000 men aged 40 to 79 years at eight test centres across Europe. The study was published in the May 2009 issue of the Journal of Neurology, Neurosurgery and Psychiatry.

In the study, researchers found that men with higher levels of vitamin D performed consistently better in a simple and sensitive neuropsychological test that assesses an individual’s attention and speed of information processing.

“Previous studies exploring the relationship between vitamin D and cognitive performance in adults have produced inconsistent findings but we observed a significant, independent association between slower information processing speed and lower levels of vitamin D,” said lead author Dr. David Lee, in Manchester’s School of Translational Medicine.

Why is this study considered especially important? “The main strengths of our study are that it is based on a large population sample and took into account potential interfering factors, such as depression, season and levels of physical activity.

nterestingly, the association between increased vitamin D and faster information processing was more significant in men aged over 60 years, although the biological reasons for this remain unclear.”

TUNA GETTING MORE TOXIC

The rate of mercury contamination in tuna and other Pacific fish has increased 30% since 1990. The increase is a direct result of China’s rapid industrialization, and the mercury content is expected to increase another 50% by 2050 if China continues to build more coal-fired power plants. The data comes from a new study by the U.S. Geologic Survey.

About 40% of all North American exposure to mercury comes from eating contaminated tuna from the Pacific Ocean. Roughly 75% of all human exposure to mercury in general comes from eating fish. Mercury poisoning early in life, even in very small amounts, can lead to permanent developmental effects. Mercury becomes toxic when it is converted by bacteria into a form called methylmercury. Scientists have long known how this conversion takes place in freshwater lakes and rivers, but this study is the first to document how that conversion takes place in the ocean. It shows that methylmercury is produced from mercury, in mid-depth ocean waters, by bacteria that decompose the settling algae. (May 1, 2009 edition of Global Biochemical Cycles.)

GINGER CUTS CHEMO NAUSEA

Ginger capsules can relieve nausea caused by chemotherapy, a new study shows. Up to 70% of patients become nauseated after chemo, according to a new study of 644 people reported at the May 28, 2009 annual meeting of the American Society of Clinical Oncology, in Orlando.

Although drugs such as Kytril can prevent vomiting, they don’t always relieve nausea, says study author Julie Ryan, assistant professor of dermatology and radiation oncology at the University of Rochester Medical Center.

Ginger, however, reduced patients’ nausea levels by half, according to the study funded by the National Cancer Institute. On a scale of one to seven – in which seven represents the worst nausea – chemo patients given placebos rated their nausea as a five or six, or very nauseous. Those given ginger, however, rated their nausea level as only two or three, Ryan said in an interview.
Patients took ginger three days before and three days after getting chemo. Patients took three capsules, twice a day. The most effective doses were one gram and 0.5 gram a day, which are equal to half a teaspoon or one-quarter of a teaspoon of ground ginger. Significantly, ginger caused no side effects.

Doctors were careful to monitor patients’ platelet levels because some earlier research suggested that ginger might act like a blood thinner. “That’s why we’re so excited. This is something that people have access to, that won’t harm them,” said Ryan, who noted that ginger capsules are commonly sold in health food stores.

Although ginger has been used as a folk remedy for nausea for centuries, this is the first time it has been so rigorously tested for chemo patients, says Richard Schilsky, PhD, oncology society president, who wasn’t involved in the study. He describes the trial’s results as “conclusive.”

Several studies have shown that ginger can relieve morning sickness during pregnancy, according to Linda Lee, PhD, director of the Johns Hopkins Integrative Medicine & Digestive Center. Doctors don’t yet understand exactly why it works. Lee noted that the U.S. Food and Drug Administration doesn’t regulate supplements such as ginger the same way as it regulates drugs.

“One of the challenges about recommending a ginger supplement is that not all brands are created equal,” Lee said. “One study looked at several ginger supplements on the market, only to find a few of them did not contain gingerol, one of the active compounds in ginger.” And Schilsky notes that because researchers didn’t test powdered or fresh ginger, they don’t know if these types are as effective as capsules.

MUSHROOM IMMUNITY BOOST

The ordinary white button mushroom — the kind found in grocery stores everywhere — can provide a substantial immunity boost, researchers at Tufts University report. This lowly fungus was thought for years to have no medicinal or great nutritional value. But the study reveals that ordinary mushrooms can support the immune system, which is important at any time but especially so in these times of swine ‘flu.

The Tufts study, published in the May 2009 issue of the Journal of Nutrition, showed that white button mushrooms have as much antioxidant oomph as more exotic Asian mushrooms, long-prized for their ability to heal and to prevent disease. Common button mushrooms also contain polysaccharides and ergothioneine, along with other substances that jump-start the immune system. And they raise levels of cytokines, which are hormone-like proteins that help defend against viruses and tumours, the study found.

How many mushrooms are enough? It is suggested that a half-cup serving a day will give full health benefits.

WALNUTS CONTROL DIABETES

Including walnuts in your daily diet can help keep type-2 diabetes under control, according to a new study conducted by a team headed by Linda Tapsell, professor at the Smart Foods Centre (SFC), University of Wollongong in Australia.

Fifty overweight adults with non-insulin treated diabetes followed a well-balanced, low-fat diet with the SFC for a year. Researchers found the group that was given 30 grams of walnuts a day had more of the good fats in their blood than those who followed a low-fat diet alone.

In an interview, Tapsell said that both groups ate healthy diets and had low intakes of saturated fats. But the walnut group showed more unsaturated fats. Most of the effects were seen in the first three months. As whole foods, the walnuts also delivered fibre, vitamin E and other components with anti-oxidant activity. The walnut group also showed improvements in insulin levels and “this may have been due to the presence of good fats in the diet,” said Tapsell.

Tapsell said the latest research confirms earlier studies conducted through her centre, highlighting the benefits to be gained by harnessing the “good” oils from walnuts, which are rich in polyunsaturated fats, omega oils and vitamins. The latest findings were published in the May 2009 edition of the European Journal of Clinical Nutrition.

VITAMIN B9 FOR ASTHMA?

Vitamin B9, or folic acid —long known to reduce the risk of spinal birth defects — may also suppress allergic reactions and lessen the severity of allergy and asthma symptoms, suggests preliminary research by Johns Hopkins scientists. The team conducted the first-ever study examining the link between blood levels of folate – the naturally occurring form of folic acid – and allergies. The results add to mounting evidence that folate can help regulate inflammatory disorders, such as asthma.

(Recent studies, including research from Hopkins, have found a link between folate levels and inflammation-mediated diseases, including heart disease.)

Cautioning that it’s far too soon to recommend folic acid supplements to prevent or treat people with asthma and allergies, researchers emphasize that more research needs to be done to confirm their results and to establish safe doses and risks.
Reviewing the medical records of more than 8,000 people aged between two and 85 years, investigators tracked the effect of folate levels on respiratory and allergic symptoms, and on levels of IgE antibodies – immune system markers that rise in response to an allergen.

People with higher blood levels of folate had fewer IgE antibodies, fewer reported allergies, less wheezing and a lower likelihood of asthma, the researchers reported. “Our findings are a clear indication that folic acid may indeed help regulate immune response to allergens, and may reduce allergy and asthma symptoms,” said lead investigator Elizabeth Matsui. “But we still need to figure out the exact mechanism behind it, and to do so we need studies that follow people receiving treatment with folic acid, before we even consider supplementation with folic acid to treat or prevent allergies and asthma.”

The current recommendation for daily dietary intake of folic acid is 400 micrograms for healthy men and non-pregnant women. Many cereals and grain products are already fortified with folate. Folate is also found naturally in green, leafy vegetables, beans and nuts, said a Hopkins release. The study appeared online in the May, 2009 issue of the Journal of Allergy & Clinical Immunology. 

SLEEP YOUR WAY TO A THINNER YOU?

You can’t sleep it off when it comes to weight, but getting a good night’s rest could be at least part of the secret to staying thin, according to a study presented at an international conference on obesity in Amsterdam.

“After a bad night’s sleep, people ate 550 calories (22%) more than normal,” said the findings of a study by the European Centre of Taste Science in Dijon in central France. That amounts to about one large hamburger.

Hunger pangs were higher among a test group who slept four hours the previous night than among those who slept eight hours, stated an extract of the findings. The European Assn. for the Study of Obesity organized the May 2009 conference. The World Health Organization estimates that about 1.6 billion adults were overweight in 2005. At least 400 million of those were obese.

PROBIOTICS REDUCE OBESITY AFTER BIRTH

Women who take probiotics during their first trimester of pregnancy may be less likely to suffer from the most unhealthy form of obesity after giving birth, according to new research. A study by scientists at the University of Turku in Finland suggests that manipulating the balance of bacteria in the gut may help to fight post-pregnancy obesity.

(Probiotics are bacteria that help to maintain a bacterial balance in the digestive tract by reducing the growth of harmful bacteria. They are part of the normal digestive system and play a role in controlling inflammation.)

Researchers have, for many years, been studying the potential of using probiotic supplementation to address a number of intestinal diseases. More recently, obesity researchers have investigated whether the balance of bacteria in the gut might play a role in making people fat.

The results of the study, presented in May at the European Congress on Obesity, were an encouraging sign of the impact of a diet supplemented with probiotics on adiposity. Adiposity, or central obesity, is a particularly unhealthy form of obesity associated with fat bellies.

“The women who got the probiotics fared best,” she said. “One year after childbirth, they had the lowest levels of central obesity as well as the lowest body fat percentage.

One of the test groups received daily capsules of probiotics containing Lactobacillus and Bifidobacterium, which are the most commonly used probiotics. The other group received dummy capsules.

Central obesity – defined as a body mass index (BMI) of 30 or more or a waist circumference more than 80 centimetres – was found in 25% of the women who had been given the probiotics, as well as diet advice. That compared with 43% of the women who got dietary counselling alone and 40% of the women who got neither diet advice nor probiotics. The average body fat percentage in the probiotics group was 28%, compared with 29% in the diet advice only group and 30% in the third (no advice-no probiotics) group.

The study author said that further research was needed to confirm the potential role of probiotics in fighting obesity. One of the limitations of the study was that it did not take into account the mothers’ weight before pregnancy, which may influence how fat they later become.

NEWSNOTES

Child ‘flu vaccine increases risk: ‘Flu vaccine does not help children stricken with influenza to stay out of the hospital, but instead triples their risk of being hospitalized compared with those who have not had shots, according to a new study at the Mayo Clinic. The relative benefit of the vaccine is of paramount importance in light of the recommendation of the Centers for Disease Control and Prevention and the American Academy of Pediatrics to vaccinate all children between six months and 18 years every year.
Elderly immune to swine ‘flu? More than 64% of 5,764 probable cases of American infections of H1N1 flu have occurred among patients between the ages of five and 24, with just 1% of ‘flu victims 65 or older, according to a study at the U.S. Centers for Disease Control and Prevention (CDC). One possible explanation is that “older adults might have been in contact a long time ago with a virus related to the one that we see now,” said Anne Schuchat, interim deputy director for science and public health programs at the CDC, in an e-mail interview with News Briefs.
Curcumin benefit? Results from a new animal model study by Agricultural Research Service (ARS) funded scientists and colleagues theorized that dietary curcumin could stall the spread of fat-tissue by inhibiting new blood vessel growth (known as angiogenesis) which is necessary to build fat tissue. The study results were published in the May, 2009 issue of the Journal of Nutrition.
Selenium cuts skin cancer risk: A new Australian study found relatively high-serum selenium concentrations are associated with a 60% decrease in subsequent tumour incidence of both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The study appeared in the May 2009 issue of Cancer Epidemiological Biomarkers Preview.
Vitamin D reduces diabetes, heart risk: Spending more time in the sun could help elderly individuals cut their risk of diabetes and heart disease, according to research published in the May issue of Diabetes Care. The study results were presented at the May 1, 2009 National Lipid Association Annual Scientific Sessions in Miami, Florida, and confirm an important role of vitamin D nutrition for maintaining cardiovascular health. The study shows that a vitamin D deficiency increases the risk of metabolic syndrome. Metabolic syndrome’s cluster of obesity, high blood sugar, high blood pressure and high cholesterol can lead to heart disease, stroke and diabetes. Vitamin D is mainly obtained from exposure to the sun, plus supplements and certain foods such as oily fish and eggs.
Supplements fight insomnia: The Council for Responsible Nutrition (CRN) and Better Sleep Council are promoting healthy steps consumers can take to improve their sleep. Particularly in today’s stressful economy, committing to a healthy lifestyle that includes a balanced diet, healthy exercise and appropriate supplements can combat stress and enhance sleep quality. “Herbals and other dietary supplements can be safe and effective ways to help individuals achieve quality sleep,” said Douglas MacKay, N.D., vice president, scientific and regulatory affairs, CRN. Among MacKay’s top choices for supplements to help reduce stress or promote healthy sleep: melatonin, magnesium, calcium, valerian and 5-HTP.
Job loss can make you sick: In the face of rising unemployment and business bankruptcy, a new study has found that losing your job can make you sick. Even when people find a new job quickly, there is an increased risk of developing a new health problem, such as hypertension, heart disease, heart attack, stroke or diabetes because of the job loss, according to the study published in the May 8 issue of Demography.
Dowager’s hump risk: Researchers reported in a study published in the May 19, 2009 issue of the Annals of Internal Medicine that older white women with both vertebral fractures and the increased spinal curvature that results in the bent-over posture characteristic of hyperkyphosis – known as “dowager’s hump” – had an elevated risk for earlier death. The finding was independent of other factors that included age and underlying spinal osteoporosis. Women who had only hyperkyphosis without vertebral fractures did not show an increased risk for premature death.
U.S. ranks last: The United States ranked dead last in sustainability in the newly-released, second annual National Geographic Greendex survey. But the study also shows that Americans are increasingly becoming more aware of how their purchasing decisions impact the environment.