Here's a good answer:
http://www.nutraingr...cause-mortality"Dr. Bjelakovic was contacted by NutraIngredients.com and asked to comment on the exclusion of the 405 death-free trials, and to contextualise why most of the trials included in the meta-analysis tested for secondary prevention, looking at how a nutrient works in diseased populations, instead of primary prevention studies in healthy populations. No response was received by NutraIngredients.com in time for publication.
Stinging criticism
The dietary supplements industry has responded strongly to the review, with the Council for Responsible Nutrition (CRN), an industry association, releasing a statement that read: "Although [the authors] have updated their meta-analysis, by handpicking additional studies and correcting a litany of minor mistakes made in previous versions, it is for all intents and purposes not a new study, nor is it truly new information.
"In fact, it appears to be a systematic attempt by the authors to publish work that supports their own pre-determined conclusions about antioxidants and the way they should be regulated."
John Hathcock, Ph.D., senior vice president, scientific and international affairs, CRN, was quick to draw attention to the exclusion criteria employed by the researchers.
"With nearly 750 studies to choose from, it's interesting that they chose to include only 67 studies - less than nine percent of the total clinical trials on antioxidants that are available," said Dr. Hancock. "Moreover, the possible 750 clinical trials do not even account for other sources of evidence, such as observational studies, which were not considered by the authors at all. It is their exclusions, not the inclusions, where the fault lies."
"The conclusions one can reach from this meta-analysis are very limited."
When the meta-analysis was published initially in JAMA, Meir Stampfer, a professor of nutrition and epidemiology at the Harvard School of Public Health who was not connected to the meta-analysis, told the Associated Press that the studies reviewed were too different to be able to pool them together.
"This study does not advance our understanding, and could easily lead to misinterpretation of the data," Stampfer told the AP.
Similar comments were forthcoming from the UK natural health industry association, the Health Food Manufacturers' Association (HFMA). A spokesperson stated that the review was "systematically flawed."
"The analysis focused on one broad category of study, then evaluated just 67 of the 748 studies that could be included in the review. Therefore, the paper's conclusions are drawn on less than nine per cent of available evidence. In no way can this review be considered comprehensive," said the spokesperson.
"Antioxidant supplements cannot be expected to undo a lifetime of unhealthy living, but combined with good lifestyle choices, can play an important role in promoting overall health and wellbeing."
Pointing out the practicalities
Andrew Shoa, Ph.D., CRN's vice president, scientific and regulatory affairs said: "It really comes down to whether or not this meta-analysis should mean anything to consumers or scientists. And from a practical standpoint, it doesn't mean much.
"We maintain that healthy consumers who are using antioxidant supplements in the manner that they were meant to be used-as complements to, not in place of-other healthy lifestyle habits, can continue to feel confident in the benefits these supplements provide.
"For those consumers who are seriously ill with cancer, heart disease, etc., they should talk with their doctor about everything they put into their bodies."
