In The News: January 2010

A report published in the Canadian Medical Association Journal revealed the results of a study conducted by researchers in Greece which found a significant reduction in mortality in several countries during the late summer months of August and September compared with the remainder of the year.*

Researchers at the Alfa Institute of Biomedical Sciences examined mortality statistics for 11 countries for up to 57 years. For the five Mediterranean countries included in the study, September had the lowest average daily mortality. August emerged as the month with the lowest mortality for Sweden, Canada and the United States. Although only two years of data were available for Japan, mortality was lowest in July. For Australia and New Zealand, average mortality was lowest in March and February (summer months in the southern hemisphere).

“Greater exposure to sunlight leads to increased synthesis of vitamin D, which may have beneficial effects for cardiovascular disease, renal failure, certain malignant diseases, autoimmune disorders and infections, including influenza,” they write.

—Dayna Dye

Researchers from Johns Hopkins University School of Medicine and other centers report in the journal Nutrition Research the finding of a lower risk of death over 72 months of follow-up for older women with high serum vitamin D levels.

Richard D. Semba and his associates analyzed data from participants in the Women’s Health and Aging studies I and II. For their study, the researchers selected 714 women in their seventies who had their serum 25-hydroxyvitamin D levels measured upon enrollment.

Only 8% of women in the top quartile of vitamin D serum status died compared to 19.2% in the lowest quartile. Stated differently, those with the higher vitamin D serum levels were almost 2.5 times less likely to die over the six-year study period.*

The findings confirm those of two analyses published last year in the Archives of Internal Medicine.

—Dayna Dye

Research conducted at the University of Leicester in England contributes to the understanding of the mechanisms involved in vitamin C’s ability to help heal and protect the skin.* The vitamin is a cofactor for the synthesis of collagen, the predominant protein in skin.

Tiago Duarte and his associates previously reported the discovery of the upregulation of DNA repair in vitamin C supplement users. The current research examined gene expression and DNA damage and repair in human skin cells known as dermal fibroblasts (which play a role in wound healing) that were exposed to a derivative of vitamin C.

In addition to vitamin C’s ability to scavenge free radicals, Dr. Duarte’s team uncovered additional mechanisms for the vitamin in repairing the skin and protecting it from further damage. “The results demonstrated that vitamin C may improve wound healing by stimulating quiescent fibroblasts to divide and by promoting their migration into the wounded area,” Dr. Duarte explained.

—Dayna Dye

The American Heart Association’s 63rd High Blood Pressure Research Conference was the site of a presentation concerning the finding that low vitamin D levels prior to menopause are associated with an increased risk of elevated systolic blood pressure 15 years later.*

For their research, Flojaune C. Griffin, MPH, and colleagues evaluated data from 559 women enrolled in the Michigan Bone Health and Metabolism Study. While just 6% of the participants had systolic hypertension at the beginning of the study, 19% had been diagnosed by 2007 and an additional 6% had undiagnosed systolic hypertension. Women who had deficient levels of vitamin D in 1993 had a three times greater risk of developing systolic hypertension by 2007 than women with normal levels.

“This study differs from others because we are looking over the course of 15 years, a longer follow-up than many studies,” stated Griffin.

—Dayna Dye

An article published in the Journal of Gerontology: Medical Sciences reported the results of a study of men and women aged 65 and older which revealed risk factors associated with dying over a 13 year average period.*

Researchers evaluated data from 5,888 participants in the Cardiovascular Health Study Cohort. Median survival time was over 80 years for male participants and 87 years for women. Age, smoking status, pulmonary function, weight, cognitive function, heart failure history, heart disease history, self-reported health status, the apoE E4 allele, and most cardiovascular measures were associated with all-cause mortality over follow-up. Other than age, the risk factor most consistently associated with death across all causes was interleukin-6, a marker of immune function dysregulation which is elevated during chronic inflammation. “In terms of prevention, this study suggests that approaches that target cardiovascular disease and inflammation have the greatest potential to increase longevity,” the authors conclude.

—Dayna Dye

An article appearing in the journal Obesity reported the findings of Chinese researchers of improvements in weight and body composition in men and women who consumed green tea that contained high amounts of catechins.*

Researchers at Fudan University in China divided 182 moderately overweight Chinese men and women to receive beverages containing varying amounts of catechins for 90 days. By the end of the study, total body fat and body fat percentage were lower in the group that received the highest amount of catechins compared to the control group. In the highest catechin group, intra-abdominal fat area and weight were lower, and waist circumference averaged 1.9 centimeters less than those who received the control beverage.

“In this latest research, green tea providing significant catechin levels helped promote weight loss and positively affected body shape,” lead researcher Dr. Niels Boon concluded.

—Dayna Dye

The 2009 American Academy of Otolaryngology-Head and Neck Surgery Foundation Annual Meeting & OTO EXPO, held this year in San Diego, was the site of a presentation of research conducted at Brigham and Women’s Hospital in Boston which found a protective effect for the B vitamin folate against the development of hearing loss in older men.*

For their research, Josef Shargorodsky, MD and his colleagues analyzed data from 26,273 male dentists, optometrists, osteopaths, pharmacists, podiatrists, and veterinarians who were 40-75 years of age upon enrollment in the Health Professionals Follow-Up Study in 1986. Health and dietary questionnaires completed every two years were analyzed for the intake levels of several vitamins, including folate. Questionnaires completed in 2004 obtained information on hearing loss diagnosed since the beginning of the study.

Over the course of the follow-up, 3,559 men developed hearing loss. Although no association was noted between the condition and other vitamin intake, men over 60 whose intake of folate from food and supplements was among the highest 20% of participants had a 21% reduction in the risk of developing hearing loss compared with those in the lowest fifth. The intake of alcohol, which can impede the bioavailability of folate, did not impact the relationship observed between folate intake and hearing loss, however, men whose alcohol intake was highest had a reduced risk of hearing loss with greater vitamin B12 intake.

The investigation is the first large epidemiologic study to prospectively examine the relation between diet and hearing loss. “The association between folate intake and incident hearing loss in our cohort is consistent with previous data showing that folic acid supplementation slowed the decline in low frequency hearing in older adults,” the authors write.

“A possible explanation for the impact of age on the relation between folate intake and hearing loss is the increased prevalence of folate malabsorption and folate depletion in the older age group. Higher folic acid intake may be necessary to meet the optimal folate needs in this age group.”

—Dayna Dye

According to the most recent statistics available from the US National Poison Data System, there was not even one death caused by a vitamin or dietary mineral in 2007. The 132-page annual report of the American Association of Poison Control Centers published in the journal Clinical Toxicology shows zero deaths from multiple vitamins; zero deaths from any of the B vitamins; zero deaths from vitamins A, C, D, or E; and zero deaths from any other vitamin.*

Furthermore, there were zero deaths in 2007 from any dietary mineral supplement. This means there were no fatalities from calcium, chromium, zinc, colloidal silver, selenium, iron, or multimineral supplements. Sixty-one poison centers provide coast-to-coast data for the US National Poison Data System, which is then reviewed by 29 medical and clinical toxicologists. In 2007, NPDS reported 1,597 fatalities from drugs and other ingested materials. Not one death was due to a vitamin or dietary mineral supplement.

—Jon Finkel

A report published in the October 11, 2009 issue of the International Journal of Low Radiation added evidence to a protective effect for Ginkgo biloba against radiation damage. Ginkgo biloba is a tree species whose leaves have been used for centuries in Chinese medicine. Ginkgo leaf extract contains antioxidant compounds called ginkgolides and bilobalides which help scavenge free radicals that attack nearly all components of the cell, including DNA.*

In their article, Chang-Mo Kang of the Korea Institute of Radiological and Medical Sciences in Taegu and colleagues describe their use of an assay for radiation-induced programmed cell death (apoptosis) to evaluate the protective effect of ginkgo extract against radiation exposure that occurs during accidents or occupational overexposure. In one experiment, white blood cells from human donors aged 18 to 50 were treated with one of four concentrations of ginkgo extract or a 9% saline solution before being exposed to gamma rays.

The researchers found a significant dose-dependent reduction in apoptotic cells among those treated with ginkgo. While radiation-induced apoptosis occurred in nearly one third of irradiated cells not treated with ginkgo, the number declined to 5% or less in cells treated with the highest concentration of the herb.

In another experiment, mice were treated with ginkgo extract or saline before and after receiving whole body ionizing radiation. Mice that did not undergo radiation served as controls. Examination of the animals’ spleens found that treatment with ginkgo maintained organ size comparable with that of animals that did not receive radiation, while spleens in irradiated animals that did not receive ginkgo were significantly smaller.

In their discussion of the findings, the authors note that cell-damaging free radicals and reactive oxygen species can be generated in excess under numerous conditions, including exposure to environmental chemicals, specific drugs, and during normal aging.

“These results indicate that the radioprotective effects of ginkgo extracts administered prior to radiation are due to the OH radical scavenging activity,” the authors write. “Therefore, ginkgo extract should be useful for the protection of radiosensitive organs against free radicals.”

—Dayna Dye