You may have seen various news reports today about a Danish study on antioxidants. Headlines state things like Vitamins may increase risk of death – study. Well, I've obtained a copy of the actual study. It was a meta-analysis, meaning it reviewed lots of other studies and tried to do an overall analysis. The researchers' conclusion?
Treatment with beta carotene, vitamin A, and vitamin E may increase mortality. The potential roles of vitamin C and selenium on mortality need further study.
The study is titled Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention: Systematic Review and Meta-analysis by Bjelakovic et.al. (27) and published in the February issue of JAMA – the Journal of the American Medical Association
Now, let me say upfront I'm not a fan of this type of study. Meta-analysis can easily be confounded by the different types of studies included. For example, two-thirds of the studies included in the Bjelakovic paper involved people with heart disease, cancer or other risks who were being treated to see if the supplements helped. In other words, they were being used to see if vitamins, and in particular anti-oxidants, were an effective treatment – not whether they had a preventative effect. It's already been fairly well established that, for example, beta-carotene has a negative effective on mortality of smokers. There's even been a possible mechanism for this established. Treatment studies are not necessarily applicable to prevention. The studies also covered an enormous range of dosage. The Vitamin A studies included had dosages ranging from 1333 to 2 IU (American RDA for adult males is around 3IU/day). Some studies also gave mutliple supplements, some gave single supplements. All in all, in my opinion, the extreme lack of homogeneity raises questions about the validity of a meta-analysis approach.
Because we examined only the influence of synthetic antioxidants, our findings should not be translated to potential affects of fruits and vegetables.
One of the key features of Nutrilite and Nutriway products is the use of plant concentrates rather than synthetics. When the science supports it, some synthetics are used to boost levels of particular nutrients, but the key ingredients come not out of a chemistry laboratory but from fruits and vegetables. That's the Nutrilite Difference and probably one of the reasons why Nutrilite keeps topping consumer satisfaction surveys.