Wikipedia talk:Mediation Cabal/Cases/2007-03-28 Antioxidant

message: Okay. I'd like to open by mentioning that it looks, from what I'm seeing right now, as though Wikipedia policy would agree with Paul on the subject of his source. I don't want anyone to think I've lost my neutrality, as I will happily change that position if it comes to light that I am mistaken. I'm basing my conclusion on the following:
*Wikipedia policy does not state that a peer-reviewed source is MORE reliable than a non-peer-reviewed source, so long as the non-peer-reviewed source is still reliable.
*Even if Wikipedia policy did state that a peer-reviewed source were more reliable, it can be reasonably argued that Paul's source is peer-reviewed to the best of its ability.
*Wikipedia policy DOES state that all positions must be given due weight if they carry proper sourcing.
*It is unfair to remove a plainly valid position on the basis that if it's valid, another source will eventually pick it up. Paul's source, while not exactly the New American Dictionary of Medicinal Studies, appears to me (and I am admittedly not terribly knowledgeable regarding medicine) to be written by individuals familiar with the field and it appears to be a valid source under Wikipedia policy, so Paul's position must be given due weight.
*Due to the limited availability of published material on the subject, I would argue that under Wikipedia policy, the study and those criticizing it should be given equal weight and the decision should be left, ultimately, to the reader of the article.
However. It also appears to me that the real problem here isn't in the source, it's in the amount of weight being given to the position associated with it. After reading the article's talk page, it looks like both of your versions of the paragraph give undue weight to your own positions. So, unless one of you disagrees with me, I think what we should really focus on is coming up with a version of that paragraph that gives each position more equal weight. --Moralis (talk) 18:08, 12 April 2007 (UTC)
thread_title:  Opening Comments from the Mediator 

message: These harmful effects may also be seen in non-smokers, as a recent meta-analysis including data from approximately 230,000 patients suggested that β-carotene, vitamin A or vitamin E supplementation is associated with increased mortality, but saw no significant effect from vitamin C.[132] No health risk was seen when all the randomized controlled studies were examined together, but an increase in mortality was detected only when the high-quality and low-bias risk trials were examined separately. However, as the majority of these low-bias trials dealt with either elderly people, or people already suffering disease, these results may not apply to the general population.[2] On the other hand, these results are consistent with some previous meta-analyses that also suggested that Vitamin E supplementation increased mortality,[133] and that antioxidant supplements increased the risk of colon cancer.[134] Conversely, these results are inconsistent with other recent meta-analyses, which suggested that antioxidants have no positive or negative effects on all-cause mortality.link link. Overall, the large number of clinical trials carried out on antioxidant supplements suggest that either these products have no effect on health, or that they cause a small increase in mortality in elderly or vulnerable populations.[109][110] TimVickers 22:42, 16 April 2007 (UTC)
thread_title: Compromise version

message: *malnourishment in children
::Yes, vitamin supplementation can treat vitamin deficiency, but this isn't what we're talking about.
 
*cancer
::From the first study cited "Our results do not provide strong support for population-wide implementation of high-dose antioxidant supplementation for the prevention of prostate cancer. However, vitamin E supplementation in male smokers and beta-carotene supplementation in men with low dietary beta-carotene intakes were associated with reduced risk of this disease." Second study is an associative study, which (as outlined above) does not prove A causes B
 
*vascular disease
::Associative study.
 
*immune deficiency
::Studied a multivitamin mix including B vitamins in HIV patients, cannot be described as a trial of antioxidants as B vitamins are not antioxidants. Moreover, HIV patients were not part of the JAMA meta-analysis so this study is not relevant to it's conclusions. The 2005 meta-analysis of these clinical trials concluded "There is no conclusive evidence at present to show that micronutrient supplementation effectively reduces morbidity and mortality among HIV-infected adults." link
 
*stroke 
::Associative study.
*age-related dementia
::Associative study.
*aging
::Associative study.
These results have been reviewed in one of the reviews I linked to earlier:
::Observational cohort studies have demonstrated an association between high intakes of micronutrients such as vitamin E, vitamin C, folic acid and beta-carotene, and lower risk of CHD, stroke and cancer at various sites. However, randomised intervention trials of micronutrient supplements have, to date, largely failed to show an improvement in clinical end points. The discordance between data from cohort studies and the results so far available from clinical trials remains to be explained. One reason may be that the complex mixture of micronutrients found, for example, in a diet high in fruit and vegetables may be more effective than large doses of a small number of micronutrients, and therefore that intervention studies that use single micronutrient supplements are unlikely to produce a lowering of disease risk. link
As the JAMA study examined the randomised controlled trials, rather than these cohort and associative studies, its conclusions are entirely consistent with the data above. It would be misleading to use data from associative studies, which cannot prove anything apart from A and B commonly appearing together, to dispute the results of the more reliable randomised controlled trials. TimVickers 22:44, 17 April 2007 (UTC)
thread_title: Alternative studies