Canadian study indicates that quality of nutritional supplements is still a concern

In a recent study, researchers discovered that more than half of the nutritional supplements tested did not disintegrate properly. Included in the test were 39 tablets and 10 capsules containing minerals and vitamins commercially available on the Canadian market. USANA's Multimineral was included in the test. The first disintegration stage was performed using Simulated Intestinal Fluid (SIF) pH 6.8 for 20 minutes. Products which did not disintegrate were further analyzed using USP disintegration conditions for dietary supplements. Of the 39 tablets tested, only 18 products (which included Usana's Multimineral) disintegrated fully at the first stage. The 21 tablets that did not pass the first stage were then tested for disintegration using USP conditions. Nine tablets still failed to disintegrate, including all three timed-release products tested. Forty-percent of the capsules also failed the first stage, although all ten eventually passed when subjected to USP testing conditions.

This study illustrates that disintegration, one basic indicator of product quality, is still a concern for dietary supplements.

J Pharm Pharmaceut Sci (www.cspsCanada.org) 9(1):40-49, 2006
http://www.ualberta.ca/~csps/JPPS9 (1)/Loebenberg.R/tablets.pdf

Zinc supplements decrease incidence of infections in the elderly

Elderly adults are increasingly susceptible to infections, oxidative stress and immune dysfunction. According to new research, supplementing with zinc for one year decreased the incidence of infections and lowered markers of oxidative stress in a group of adults aged 55-87 years.

Adults over the age of 55 years are more susceptible to infections, immune dysfunction, increased oxidative stress, and zinc deficiency. Since zinc has anti-inflammatory and antioxidant properties, new research sought to determine the effect of zinc on the incidence of total infections in the elderly.

Researchers also tested the effect of zinc on markers of oxidative stress. A randomized, double-blind, placebo-controlled trial of zinc supplementation was conducted in 50 healthy subjects of both sexes aged 55-87 years. The zinc- supplemented group received 45 mg of zinc orally for 12 months. Incidence of infections during the supplementation period was documented. Plasma zinc concentrations and markers of oxidative stress were measured at the beginning and after supplementation.

After zinc supplementation, the incidence of infections was significantly lower, plasma zinc was significantly higher, and generation of oxidative stress markers was significantly lower in the zinc-supplemented than in the placebo group.

American Journal of Clinical Nutrition, Vol. 85, No. 3, 837-844, March 2007

Vitamin D deficiencies widespread among pregnant women and infants despite prenatal vitamin usage

Vitamin D deficiency early in life is associated with rickets, a disorder characterized by soft bones. New research has shown that despite taking a prenatal vitamin, vitamin D deficiency is very common in pregnant women and newborn infants. Higher-dose supplementation and increased sun exposure is needed to improve maternal and infant vitamin D status.

Even among those taking prenatal multivitamin supplements, vitamin D levels were found to be insufficient or deficient in pregnant women, particularly in African-American women and women living in northern regions, according to new research published in the Journal of Nutrition. Researchers took blood samples from 400 pregnant women - 200 black women and 200 white women - before 22 weeks gestation and again after delivery.

More than 80% of African American women and nearly half of white women tested at delivery had levels of vitamin D that were insufficient, even though more than 90% of them used prenatal vitamins during pregnancy.

In addition, umbilical cord blood from newborns showed 92.4% of African American babies and 66.1% of white infants had insufficient vitamin D levels at birth, leaving them at risk for rickets and other health problems. A newborn relies completely on its mother for its vitamin D stores.

These results suggest that black and white pregnant women and newborns residing in the northern US are at high risk of vitamin D insufficiency, even when mothers regularly take prenatal vitamins. Higher-dose supplementation is needed to improve maternal and infant vitamin D status.

J. Nutr. 137:447-452, February 2007

Higher Antioxidant Intakes Reduce Risk of Lung Cancer in Male Smokers

Research in the 1990's seemed to indicate that beta-carotene supplements may increase lung cancer risk in smokers. However, a new analysis of dietary records from one of these studies led researchers to a different conclusion. Male smokers with the highest overall antioxidant intake, including beta-carotene, actually had a reduced risk of lung cancer.

In observational studies, a high intake of individual antioxidants was related to increased lung cancer risk in male smokers. However, data from many experiments suggest that there are interactions among antioxidant nutrients; therefore, consideration of multiple antioxidants simultaneously may be important in terms of assessing risk.

Yale University researchers evaluated dietary records of participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC). A group of over 27,000 Finnish male smokers aged 50-69 had food records analyzed along with intakes of carotenoids, flavonoids, vitamin E, selenium, and vitamin C. After evaluating the overall intake of antioxidants in this group, the conclusion differs somewhat from the original study.

According to this new analysis, the men with higher overall intakes of antioxidants had lower relative risks of lung cancer, regardless of their assigned study group (beta-carotene or placebo). While researchers of the ATBC study concluded that high-dose beta-carotene supplementation may increase lung cancer risk in male smokers, these findings support the hypothesis that a combination of dietary antioxidants reduces lung cancer risk in men who smoke.

Am J Epidemiol 2004 Jul 1;160(1):68-76

JAMA Meta-analysis of Antioxidants - Flawed Data, Biased Analysis, and Inappropriate Conclusions

Recent news stories sensationalizing the results of a new controversial study reported in the February 28, 2007 issue of the Journal of the American Medical Association (JAMA) imply that antioxidants do not have health benefits, and in fact, may lead to increased mortality. In our analysis of this study, we see little or no evidence to support this conclusion.

It is important to understand that this current study is not a new clinical trial, but a statistical analysis determined from many studies (called a meta-analysis). Meta-analysis studies are actually designed to pool similar studies for statistical comparison. However for this meta-analysis, the authors combined studies that differed vastly in design, use rates, duration, and study population. After careful review, it appears that the authors simply analyzed data that fit a predetermined conclusion, which is an invalid use of a statistical method. This is a great example of improper statistical use in research methodology.

There is a large body of data including observational studies, prospective epidemiological studies and randomized clinical studies that have shown positive benefits of antioxidant supplementation (including reduced cardiovascular disease, some cancers, immune support and reduced progression of eye disease). Interestingly, these studies were excluded from the analysis. And while the initial analysis examined 1201 research papers from 815 trials, only 68 trials were actually used in the final analysis.

Furthermore, when the initial results from this data did not show any effect on death rates, the authors removed an additional 21 studies (called a sub analysis) to draw their conclusion that supplements increase risk of mortality. Interestingly, in these 47 remaining studies, the doses used greatly exceeded normal use rates, and in many cases, were well above tolerable upper intake limits (UL) (i.e. they used doses that may not be safe). In contrast, the studies eliminated from this study generally used doses that did not exceed the UL and were more in line with actual use rates.

Finally, the majority of the studies examined are secondary prevention studies. That is, the study populations had already been diagnosed with diseases such as heart disease and cancers. This is a very risky population to study, and conclusions from these studies should not be used to make recommendations for prevention in generally health populations.

We are not the only ones who have criticized these results. Several scientific organizations and other researchers have already published criticisms of this paper. Professor Balz Frei director of the Linus Pauling Institute at Oregon State University stated:

"This is a flawed analysis of flawed data, and it does little to help us understand the real health effects of antioxidants, whether beneficial or otherwise. Instead of causing harm, the totality of the evidence indicates that antioxidants from foods or supplements have many health benefits, including reduced risk for cardiovascular disease, some types of cancer, eye disease and neurodegenerative disease. In addition, they are a key to an enhanced immune system and resistance to infection. The "meta-analysis" published in JAMA, which is a statistical analysis of previously published data, looked at 815 antioxidant trials but included only 68 of them in its analysis. And two of the studies excluded " which were published in the Journal of the National Cancer Institute and the prominent British medical journal Lancet " found substantial benefits and reduced mortality from intake of antioxidant supplements."

"If these two large studies had been included, none of the reported effects on increased mortality would have been significant, with the exception of the effects of beta carotene. And the research showing a higher incidence of lung cancer in smokers who take supplements of beta carotene or vitamin A is old news, that's been known for many years. Very high doses of vitamin A are known to have multiple adverse health effects."

"All the new study really demonstrates, is a bias toward identifying studies or research that show harm caused by antioxidants, and selective removal of research that shows benefits."

We don't know why the authors chose to evaluate this small carefully selected group of studies, or why they ignored the larger body of evidence published on the benefits of antioxidants. But it appears to be an obvious attempt to sensationalize incomplete data that serves no purpose other than to alarm a large portion of the supplement using population. We are not fooled by this report.

The full text of the Linus Pauling Institute press release can be found at:
http://oregonstate.edu/dept/ncs/newsarch/2007/Feb07/vitaminstudy.html

Additional comments on the JAMA study can be found at the following links:

http://www.crnusa.org/PR07_JAMA_antioxidant_metaanalysis_022707.html

http://www.nutraingredients.com/news/ng.as p?n=74582&m=1NIE228&c=cyqrgoymvgyorow

http://www.naturalproductsassoc.org/site/DocServer/Response_to_JAMA _Antioxidant_Study_2-27-07.pdf?docID=3201