In The News: November 2010

A recent study performed by researchers at the Mayo Clinic discovered that putting on as little as 9 pounds of fat in the abdominal area puts even young, healthy people at risk for developing endothelial dysfunction.*

The study, led by Virend Somers, MD, PhD, a cardiologist at the Mayo Clinic, examined 43 healthy Mayo Clinic volunteers with a mean age of 29 years. The volunteers were then tested for endothelial dysfunction by measuring the blood flow through their arm arteries. Each person was assigned to either gain weight or maintain their weight for 8 weeks. The weight-gainers were then instructed to lose weight and were retested.

Of the volunteers who gained visceral fat (abdominal fat), researchers found that the regulation of blood flow through their arm arteries was impaired due to endothelial dysfunction. When the volunteers lost weight, the blood flow recovered.

“Endothelial dysfunction has long been associated with an increased risk for coronary artery disease and cardiovascular events,” Dr. Somers says. “Gaining a few pounds in college, on a cruise, or over the holidays is considered harmless, but it can have cardiovascular implications, especially if the weight is gained in the abdomen.”

—Jon Finkel

An article published online in the Journal of Nutrition describes the outcome of a trial of obese men and women with metabolic syndrome which found a protective effect for blueberries against several cardiovascular disease risk factors.*

Researchers at Oklahoma State University randomized 4 men and 44 women to receive a beverage containing 50 grams freeze-dried blueberries or an equivalent amount of water daily for 8 weeks. At the treatment period’s conclusion, those who received blueberries had greater decreases in systolic and diastolic blood pressure compared to the controls. This group also experienced significantly greater reductions in plasma oxidized low-density lipoprotein (ox-LDL) and markers of oxidative stress.

“Our study findings suggest a cardioprotective role of dietary achievable doses of blueberries in men and women with metabolic syndrome, which includes a significant decrease in systolic and diastolic blood pressures and plasma ox-LDL and lipid peroxidation,” the authors write.

Editor’s note: A convenient year-round option is an encapsulated blueberry extract supplement.

—D. Dye

The Journal of Nutrition reports a reduction in the risk of dying from coronary heart disease (CHD) among men and women who consumed high fiber diets.*

Researchers evaluated data from 58,730 participants in The Japan Collaborative Cohort Study for Evaluation of Cancer Risks, carried out between 1988 and 1990. Follow-up was conducted until the end of 2003, during which 422 deaths from CHD, 983 from stroke and 675 from other cardiovascular disease were documented.

For men whose total, insoluble, and soluble fiber intakes were among the highest one-fifth of participants, there was a lower risk of dying of heart disease compared to those whose intakes were among the lowest fifth. Similar risk reductions were observed among women.

“Our results constitute supporting evidence that higher intake of both insoluble and soluble fiber, especially fruit and cereal fibers may contribute to the prevention of CHD in Japanese men and women,” the authors conclude.

Editor’s note: The authors list fiber’s cholesterol- and blood pressure-reducing effects, as well as its ability to improve insulin sensitivity, inhibit post-meal rises in glucose and triglycerides, and increase fibrinolytic activity, as mechanisms that prevent or delay the development of atherosclerosis.

—D. Dye

A report published online in The Journal of Clinical Endocrinology & Metabolism reveals the finding of a trial conducted at Kaleida Health’s Diabetes-Endocrinology Center of Western New York of an anti-inflammatory benefit for an extract of Polygonum cuspidatum, which contains resveratrol.*

Twenty healthy participants were randomized to receive a dose providing 40 milligrams resveratrol per day or a placebo for 6 weeks. Blood samples were analyzed for indices of oxidative and inflammatory stress, in addition to other factors.

The research team found a reduction in reactive oxygen species, which are unstable molecules that provoke oxidative stress and inflammation, in participants who received resveratrol. The resveratrol group also experienced a decrease in the inflammation protein tumor necrosis factor-alpha as well as inflammation markers interleukin-6 and C-reactive protein (CRP). “These actions, demonstrated for the first time in vivo, are consistent with potential anti-atherogenic and anti-aging effects,” the authors write.

Editor’s note: It is possible that Polygonum cuspidatum has other beneficial compounds in addition to resveratrol.

—D. Dye

An article published in the Proceedings of the National Academy of Sciences reveals a mechanism for exercise and calorie restriction in delaying some of the effects of aging.*

Joshua R. Sanes and his Harvard University colleagues compared a synapse known as the skeletal neuromuscular junction in young adult and aged mice. Synapses are the connections that exist between nerve cells or nerves and the muscles that they control. In young neuromuscular synapses, nerve endings match up with their receptors on muscle fibers, enabling efficient transmission of brain signals to the muscle. However, in aged synapses, nerve shrinkage can reduce contact with muscle receptors, leading to muscle wasting.

Dr. Sanes’ team found a variety of age-related differences between the synapses of the young and old mice. However, animals fed a calorie-restricted diet had reductions in these age-associated changes. Additionally, one month of exercise performed by 22-month-old mice partially reversed changes that had already occurred.

Editor’s note: The findings raise the question of whether calorie restriction mimetics might elicit similar benefits.

—D. Dye

In an article published in Nutrition & Metabolism, researchers at Creighton University report that calcium supplementation is associated with a reduction in trunk fat gain and increased maintenance of trunk lean mass in postmenopausal women compared to those who received placebos.* Trunk fat includes the abdominal fat mass that becomes increasingly difficult to control as humans age.

Lan-Juan Zhao, PhD and colleagues analyzed data from 870 women who participated in a trial designed to evaluate the effects of calcium and vitamin D on fractures. The women received one of the following daily regimens: 1,400 milligrams calcium from calcium citrate or 1,500 milligrams calcium from calcium carbonate per day plus a placebo; calcium plus 1,100 IU vitamin D3; or two placebos for up to four years.

Although body mass index did not differ significantly between the groups at the end of the study, all groups that received calcium gained less trunk fat and maintained a greater amount of trunk lean mass compared to the placebo groups.

Editor’s note: The authors announce that “This is the first clinical trial in a population-based postmenopausal women cohort to observe that increasing calcium intake, in the form of non-dairy calcium supplementation, can prevent gain of fat mass and loss of lean mass.”

—D. Dye

A review published in Experimental Biology and Medicine recommends the implementation of global policy changes in order to improve the amount of vitamin D that people receive. “Responsible medicine demands that worldwide vitamin D nutritional guidelines reflect current scientific knowledge about vitamin D’s spectrum of activities,” writes Anthony

Norman of the University of California, Riverside and Roger Bouillon.*

The current US recommended daily intake of vitamin D is 200 IU for individuals up to the age of 50, 400 IU for those 51 to 70, and 600 IU for those over the age of 70. Dr. Norman and Dr. Bouillon suggest that an increase to 2,000 IU of vitamin D daily could reduce the incidence of a number of diseases. “It is high time that worldwide vitamin D nutritional policy, now at a crossroads, reflects current scientific knowledge about the vitamin’s many benefits and develops a sound vision for the future,” Dr. Norman observed.

Editor’s note: The authors observe that increased sun exposure to elevate vitamin D levels is not a viable option for most individuals due to the carcinogenicity of ultraviolet B.

—D. Dye

In the journal Nutrition, researchers report the finding of an improvement in mood among acutely hospitalized patients supplemented with vitamin C.*

Thirty-two men and women hospitalized in medical and surgical wards were provided with 500 milligrams vitamin C or 1,000 international units (IU) vitamin D (as a placebo) twice per day for up to 10 days. Plasma vitamin C concentrations more than tripled in those who received the vitamin, and the group experienced a 34% average reduction in mood disturbance.

The authors observe that acutely hospitalized patients experience emotional distress for numerous reasons, and that psychological abnormalities are a feature of vitamin C deficiency. “Whether the explanation is tissue redistribution, insufficient vitamin C provision in a setting of increased catabolism, or both, a consequence of in-hospital hypovitaminosis C could be cerebral hypovitaminosis C with a resulting mood disorder that could be easily ameliorated or prevented by adequate vitamin C provision,” they conclude.

Editor’s note: While vitamin D levels rose among patients who received it, no improvement in mood was noted; however, the authors note that the short duration of the trial and low dose of vitamin D administered in this study would be insufficient to draw any conclusions concerning its effect.

—D. Dye

“Nearly the entire US population consumes a diet that is not on par with recommendations,” is the conclusion of a report published online on August 11, 2010 in the Journal of Nutrition.*

Researchers at the National Cancer Institute evaluated data from 16,338 individuals who participated in the 2001-2004 National Health and Nutrition Examination Survey. With the exception of total grains, and meat and beans, the majority of the sample surveyed failed to consume the minimum recommendations for each food group. Almost all participants failed to consume enough dark green vegetables, orange vegetables, legumes and whole grains. Total vegetable and milk recommendations were unmet by most people in over half of the age and gender groups analyzed.

“This analysis indicates that nearly the entire US population consumes a diet with fewer vegetables and whole grains than recommended and that a large majority underconsume fruits, milk, and oils relative to recommendations,” the authors write.

Editor’s note: A multinutrient supplement can help make up some of the insufficiencies incurred by an inadequate diet.

—D. Dye

The 240th National Meeting of the American Chemical Society held recently in Boston was the site of a presentation by Shibu Poulose, PhD, of the US Department of Agriculture about new findings for berries in protecting aging brains.*

Dr. Poulose studied the brain’s natural “house-cleaning” process, which involves autophagy by cells known as microglia. These cells remove and recycle toxic proteins that can interfere with brain function. “In aging, microglia fail to do their work, and debris builds up,” Dr. Poulose explained.

In experiments with mouse cells, Dr. Poulose found that blueberry and strawberry extracts inhibited a protein that interferes with autophagy. “The results strongly suggest that the benefits of both berries extend beyond the anti-oxidant and anti-inflammatory effects to cellular toxic clearance through induction of autophagy in brain,” concludes a written summary of the findings.

Editor’s note: Blueberry and other berry extracts are currently available as nutritional supplements.

—D. Dye

In an article published online in the journal BMC Physiology, French researchers report that resveratrol reduces seasonal body-mass gain in a primate model of weight gain.*

Dr. Fabienne Aujard of the Centre National de la Recherche Scientifique and her associates tested the effect of four weeks of resveratrol supplementation in grey mouse lemurs. These animals gain a significant amount of weight during the winter months by entering a daily state of inactivity (torpor) accompanied by a reduction in body temperature in order to conserve energy.

Supplementation with resveratrol reduced the animals’ seasonal weight gain by decreasing calorie intake by 13%, inhibiting the depth of daily torpor, and increasing resting metabolic rate by 29%.

“The physiological benefits of resveratrol are currently under intensive investigation, with recent work suggesting that it could be a good candidate for the development of obesity therapies,” Dr. Aujard commented.

Editor’s note: Resveratrol, which is found in red grapes and other plant foods, had been demonstrated to protect rodents from diabetes and obesity caused by a high-fat diet; however, the compound’s effects on weight loss had not been studied in higher animals.

—D. Dye