|guest on May 6, 2008 at 1:33:43 pm|
The fact that no one died during any of the clinical trials as a reason why the studies were not included is absurd. Rather do individuals involved in a clinical trial die. If they did, as happened serveral years ago involving a study doen at John Hopkins, the University were in all likelihood never see a dime of research funding ever again. the reason many of the Dietary Supplement studies are not considered credible is because they are often done by less than reputable faclities that also use a limited number a research subjects.
|guest on May 5, 2008 at 11:53:10 pm|
There are at least 27 Cochrane reviews examining the influence of antioxidant and vitamin intake on diseases ranging from cataracts to gastrointestinal tumours. The specific study being referred to, and being criticised here because it excluded studies where no subject died in either the intervention arm or the control arm of the study, was designed to ask whether antioxidant supplements have any effect on the *overall mortality* of those taking them.So, OF COURSE course it was reasonable to exclude studies in which no patients died. Such studies could not contribute data relevant to the question being asked.Quote from the abstract–“BackgroundAnimal and physiological research as well as observational studies suggest that antioxidant supplements may improve survival.ObjectivesTo assess the effect of antioxidant supplements on mortality in primary or secondary prevention randomised clinical trials.”
|guest on May 5, 2008 at 11:52:47 pm|
This is very misleading. The Cochrane reviews are independent reviews, not updated versions of other reviews. Cochrane excludes trials that are of poor quality because they are not meaningful in reaching conclusions. The reasons for exclusion are published. Suggesting that the authors picked only trials that supported their view verges on defamation. If the lead author has written elsewhere that dietary supplements don’t work, that’s because that’s what the best scientific evidence currently shows. Other reviews and the independent, unbiased Medical Letter concur. Getting nutrients from the diet appears to improve health; getting them from supplements appears to do more harm than good. Those are the facts. It is Gromley who is “twisting science” in favor of the products his company sells.