Thursday, October 29, 2009

USANA-supported clinical study demonstrates improved bone health in girls

New Study Involving Active Calcium™ Chewable Offers Promising Results

SALT LAKE CITY--(BUSINESS WIRE)--Oct. 29, 2009-- USANA Health Sciences, Inc. (NASDAQ: USNA) announced today that a third-party clinical study led by Dr. David Greene at Australian Catholic University (ACU National) found that use of USANA’s Active Calcium™ Chewable supplement improves bone health in young girls.

The double-blind, placebo-controlled study involved 20 pairs of identical twin girls, ages 9-12 years old, who were randomly assigned to receive USANA’s Active Calcium Chewable or a matching placebo. The results of the study found that after six months of supplementation, Active Calcium Chewable improved measures of bone mineral content, bone mineral density, and bone strength in these girls.

“We are delighted with the results of the ACU National study,” said Dr. Tim Wood, USANA’s Executive Vice President of Research and Development. “These results confirm the findings of a similar 2003 clinical trial conducted at the University of Utah. The ACU National study design, in which one twin received Active Calcium Chewable while her sister received the placebo, goes a step further and factors out genetic influences.”
Results of the ACU National study are particularly significant, because young women accumulate bone mass most rapidly during adolescence, and ideal skeletal development can only be achieved when dietary intakes of calcium, vitamin D, and magnesium are optimal during this period. Dr. Greene of ACU National said maximizing bone during the growing years was essential to offsetting the effects of osteoporosis in later life.

“It is estimated that only 10 to 25 percent of children and teens get adequate amounts of calcium and vitamin D,” said Dr. Christine Wood. “My own experience as a pediatrician confirms this when I question my patients about their calcium intakes. Parents and teens need to understand the potential long-term risks of chronic calcium and vitamin D deficiency during adolescence. We can’t turn back the clock as these children age into adults.”
Dr. Christine Wood is an expert in nutritional medicine for children and speaks on healthy lifestyles to parents worldwide. She is also a member of USANA’s Scientific Advisory Council.

Wednesday, October 28, 2009

Maternal vitamin D status influences early childhood dental health

For the first time, new clinical research out of Canada provides evidence for a relationship between maternal vitamin D levels and select markers of infant dental health.

The relationship between vitamin D and adult bone health is well-understood. However, until recently, less has been known about the relationship between maternal vitamin D status and infant bone health. A new study out of the University of Manitoba sheds new light on this subject by examining the relationship between maternal vitamin D status and two measures of infant dental health: enamel hypoplasia (EH) and early childhood caries (ECC).

206 pregnant women enrolled in the study during their second trimester. Serum vitamin D analyses revealed that more than a third of the women were vitamin D deficient (34.5%, deficiency defined as <= 35 nmol/L). Only 21 women had adequate levels of vitamin D (10.5%, adequacy defined as >= 80 nmol/L).

Over the next two years, 135 infants returned for a dental health examination. 21.6% had EH while 33.6% had ECC. Mothers of children with EH had lower vitamin D concentrations during pregnancy, though the result didn’t quite reach statistical significance (43.2 vs 51.4 nmol/L, p=0.07). However, mothers of children with ECC had significantly lower vitamin D levels than those whose children were caries-free (43.9 vs 52.8 nmol/L, p=0.034).

This study is the first to provide evidence for a correlation between maternal vitamin D levels and infant dental health, and additional research currently underway should shed further light on this important issue.

Source: Influence of maternal vitamin D status on infant oral health, Schroth R, Lavelle C, Moffatt ME,Proc Int Assoc Dent Res Meet, Abs 1646, 2008

Wednesday, October 21, 2009

High lutein and zeaxanthin intake associated with decreased risk of cataracts

Much of the existing lutein and zeaxanthin research has focused on a role in reducing risk of AMD (age-related macular degeneration). New research shows that lutein and zeaxanthin may also play a protective role against cataracts.

According to the World Health Organization, age-related cataracts affect some 18 million people worldwide. Cataracts can be caused by a number of factors, including trauma, disease, diabetes, genetics, and others. Over time, the breakdown of proteins in the lens of the eye results in increasingly poor vision (including reductions in visual clarity, visual acuity, and contrast sensitivity). Once developed, cataracts must be surgically removed.

Fortunately, new research from the Archives of Opthalmology provides evidence of a good correlation between high lutein and zeaxanthin intakes and decreased incidence of nuclear cataracts. A total of 1802 women (aged 50-79) initially recruited for the Women’s Health Initiative Observational Study (1994-1998) were re-recruited 4 to 7 years later as part of the Carotenoids in Age-Related Eye Disease Study.

Researchers selected participants based on whether they could be classified as having high dietary levels of lutein and zeaxanthin (78th percentile and above) or low dietary levels (28th percentile and below). Analyses revealed that women in the high dietary levels group had a 23% lower prevalence of nuclear cataracts than women in the low-level group. Dividing the participants into quintiles revealed that women in the highest quintile were 32% less likely to have nuclear cataracts when compared to women in the lowest quintile (adjusted odds ratio 0.68; P=0.04; adjusted odds ratio 0.68; P=0.01, respectively).

The researchers concluded that diets rich in lutein and zeaxanthin correlate moderately well with decreased prevalence of nuclear cataracts in older women, although additional research will be needed in order to confirm a specific mechanism for this protective effect.

Source: Associations Between Age-Related Nuclear Cataract and Lutein and Zeaxanthin in the Diet and Serum in the Carotenoids in the Age-Related Eye Disease Study (CAREDS), an Ancillary Study of the Women's Health Initiative, Moeller et al, 2008, Arch Ophthalmology 126(3):354-64

Wednesday, October 14, 2009

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