Dietary zinc intake correlates with DNA strength

Zinc is an essential mineral with a known role in maintaining DNA integrity. A recent study takes this a step further by confirming a correlation between dietary zinc intakes and DNA damage in healthy adult males.

Zinc is an essential mineral with a known role in maintenance of DNA integrity. However, until recently, no human studies have directly examined the role of zinc status on DNA damage in healthy adults.

A study published in the August 2009 American Journal of Clinical Nutrition examined the effects of varying levels of zinc intake on DNA damage in healthy adult males. Nine healthy men with reported mean daily zinc intakes of 11 mg/day were subjected to three different dietary periods.

• Days 1-13 = baseline period (11 mg zinc/day)
• Days 14-55 = zinc depletion (0.6 mg zinc/day for 1 week, then 4 mg zinc/day for 5 weeks)
• Days 56-83 = zinc repletion (11 mg zinc/day for 4 weeks with 20 mg supplemental zinc for the first 7 days)

Blood samples were collected on days 1, 13, 35, 55, and 83, and three key metrics were analyzed (DNA damage in peripheral blood cells, plasma oxidative stress, and antioxidant defense biomarkers).

As expected, dietary zinc depletion was strongly associated with increased DNA breakage in peripheral blood cells (day 13 compared with day 55, P < p =" 0.006).">

This study provides strong evidence for dietary zinc intake being a critical factor in maintaining DNA integrity in humans.

Source: Dietary zinc restriction and repletion affects DNA integrity in healthy men, Song Y, Chung CS, Bruno RS, Traber MG, Brown KH, King JC, Ho E, 2009, AJCN 90(2):321-8

Source: USANA Health Sciences

Resveratrol may help protect against Alzheimer's

Research indicates that resveratrol may play a future therapeutic or preventive role in several disorders associated with neurological damage in the brain.

A study published in Journal of Biological Chemistry has shown that resveratrol, a compound found in grapes, red wine, peanuts and berries, lowers the levels of the amyloid-beta peptides, which cause much of the neurological damage associated with Alzheimer's disease.

Researchers administered resveratrol to cells which produce human amyloid-beta and tested the compound's effectiveness by analyzing amyloid-beta levels inside and outside the cells. They found that amyloid-beta levels in the treated cells were much lower than those in untreated cells. It is thought that resveratrol acts by stimulating the degradation of these amyloid-beta peptides.

Although more research is needed, early results suggest that this natural compound may have a therapeutic potential in Alzheimer's disease. Resveratrol is currently being researched for a potential role in fighting other human amyloid-related diseases, including Huntington's, Parkinson's and prion diseases.

Source: Resveratrol Promotes Clearance of Alzheimer’s Disease Amyloid Peptides, Marambaud et al, J. Biol. Chem. Vol. 280; Issue 45: 37377-37382, 11-11-05.

Source: USANA Health Sciences

Adequate vitamin D may prevent tooth loss

Periodontal disease is a common chronic inflammatory disease and a major risk factor for tooth loss. Research indicates that vitamin D may reduce the inflammatory response that leads to periodontal disease.

A study published in the American Journal of Clinical Nutrition demonstrates a link between low blood levels of vitamin D and the incidence of gum disease. The study group included over 11,000 adults over the age of twenty. Eighty percent of those studied had inadequate vitamin D levels, and the lower their vitamin D serum levels, the greater the risk of tooth loss.

Among the men and women aged 50 and older, those with the lowest vitamin D levels had more than 25 percent more tooth loss than those in the highest range. The researchers suspect that vitamin D may cut down on the inflammatory response that leads to periodontal disease. Given the high prevalence of periodontal disease and vitamin D deficiency, these findings suggest important oral health implications related to vitamin D intake.

Source: Association between serum concentrations of 25-hydroxyvitamin D3 and periodontal disease in the US population, Dietrich et al, Am J Clin Nutr 2004 Jul;80(1):108-13.

Source: USANA Health Sciences

USANA-Supported Clinical Study Results Published in the Journal Obesity and Weight Management

USANA Health Sciences, Inc. (NASDAQ: USNA) announced today that results of a large, third-party clinical study involving USANA products, conducted at the University of Colorado Denver (UCD), have been published in the August 2009 edition of the journal Obesity and Weight Management.

The recently completed study confirms that lifestyle change can significantly improve outcomes in subjects with metabolic syndrome. Metabolic syndrome is a pre-diabetic state that involves multiple symptoms including central obesity, insulin resistance, elevated blood lipids, elevated blood glucose, and high blood pressure. The 12-week-long study was conducted with 60 people diagnosed with metabolic syndrome. Subjects followed an Internet-based lifestyle modification program that included USANA's nutritional supplements, moderate exercise and a low-glycemic diet including USANA's nutritional shakes and bars.

Over the 12-week program, subjects in the study lost an average of 12 pounds and experienced significant improvements in measures of glycemic control, cardiovascular risk factors, inflammation and antioxidant status. Importantly, by the end of the trial, one-third of the subjects no longer met the criteria for metabolic syndrome.

Holly Wyatt, a physician and faculty member of the University of Colorado's Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, oversaw the study.

"This is a very promising program that produced some very positive changes in the cardiovascular risk factors associated with the metabolic syndrome," Dr. Wyatt said. "The shifts in dietary habits to calorically restricted low-glycemic meals and the modest increases in physical activity were not only effective but also are realistic behavioral changes many people can make."

“We are thrilled with the results of this clinical study and are excited to see it published in Obesity and Weight Management,” said Tim Wood, USANA’s Executive Vice President of Research and Development. “It is gratifying to have independent confirmation that our products and approaches to healthy lifestyle management work.”

Source: Successful Internet-Based Lifestyle Change Program on Body Weight and Markers of Metabolic Health, Wyatt et al, Obesity and Weight Management, August 2009

Source: Usana Health Sciences

Prenatal multivitamin supplementation decreases low birth weight risk

New research shows that women who supplement with multivitamins have a lower risk of delivering a low birth weight infant compared to those who receive only standard iron and folic acid supplements.

An inadequate intake of micronutrients during pregnancy increases the possibility of nutritional deficiencies that can affect the normal growth of the baby. Low birth weight is often associated with increased infant mortality.

A new meta-analysis published online on June 9, 2009 in the Canadian Medical Association Journal showed that pregnant women that supplemented with multinutrient formulas experienced a reduced risk of giving birth to low birth weight babies compared with the risk experienced by women who did not receive the extra nutrients.

Researchers identified 13 trials that compared the effects of a multivitamin supplement with a placebo, or with iron and folic acid, which are currently recommended for pregnant women by the World Health Organization. Multivitamin supplements evaluated in the trials included a combination of vitamins A, B1, B6, and folic acid, and the minerals zinc, iron, and copper.

Compared to those receiving a placebo, women who supplemented with multivitamins had a 19 percent lower risk of delivering a low birth weight infant. The multivitamin group also had a 17 percent lower risk than those who received only the standard iron and folic acid supplements. The risk of preterm birth and the risk of delivering infants who were small for their gestational age were approximately the same among treatment and control groups.

Prenatal multivitamin supplementation was associated with a significantly reduced risk of low birth weight when compared with iron-folic acid supplementation alone.

Source: Effects of prenatal multimicronutrient supplementation on pregnancy outcomes: a meta-analysis, Shah et al, CMAJ. 6/2009; 180(12)