Re: This negative aricle about Antioxidets appeard in the Lancet

From: montygram (nazztrader_at_lycos.com)
Date: 10/05/04 

Date: 5 Oct 2004 12:03:29 -0700

They used select antioxidants, in supplement form. Even "vitamin E"
is several different substances, and when you raise one, you can lower
the other. Best bet now is to avoid foods high in polyunsatures and
oxidized cholesterol, and eat things like dark chocolate, blueberries,
white tea, and also things high in fats that don't oxidize much at
all, like fresh coconut oil.

stevei_h@yahoo.com (Stevei Hanson) wrote in message news:<506f3d32.0410050254.71f4fc90@posting.google.com>...
> Would appreciate input and debate on the merits of this article...its
> only a Meta Study but has managed to grab world headlines..
>
> regards
> steve
>
> Articles
>
>
> Antioxidant supplements for prevention of gastrointestinal cancers: a
> systematic review and meta-analysis
>
> Goran Bjelakovic, Dimitrinka Nikolova, Rosa G Simonetti, Christian
> Gluud
>
>
>
> --------------------------------------------------------------------------------
> Lancet 2004; 364: 1219-28
>
>
> --------------------------------------------------------------------------------
> See Comment
>
>
> --------------------------------------------------------------------------------
> The Cochrane Hepato-Biliary Group, Copenhagen Trial Unit, Centre for
> Clinical Intervention Research, Copenhagen University Hospital, H:S
> Rigshospitalet, Copenhagen, Denmark (G Bjelakovic MD, D Nikolova MA, R
> G Simonetti MD, C Gluud MD); Department of Internal
> Medicine--Gastroenterology and Hepatology, Medical Faculty, University
> of Nis, Nis, Serbia and Montenegro (G Bjelakovic MD); and Divisione di
> Medicina, Ospedale V Cervello, Palermo, Italy (R G Simonetti MD)
>
>
> --------------------------------------------------------------------------------
> Correspondence to: Dr Goran Bjelakovic, Department of Internal
> Medicine--Gastroenterology and Hepatology, Medical Faculty, University
> of Nis, 18000 Nis, Serbia and Montenegro goranb@junis.ni.ac.yu
> Summary
>
>
>
>
> Background Oxidative stress can cause cancer. Our aim was to establish
> whether antioxidant supplements reduce the incidence of
> gastrointestinal cancer and mortality.
>
> Methods With the Cochrane Collaboration methodology, we reviewed all
> randomised trials comparing antioxidant supplements with placebo for
> prevention of gastrointestinal cancers. We searched electronic
> databases and reference lists (February, 2003). Outcome measures were
> incidence of gastrointestinal cancers, overall mortality, and adverse
> effects. Outcomes were analysed with fixed-effect and random-effects
> model meta-analyses and were reported as relative risk with 95% CIs.
>
> Findings We identified 14 randomised trials (n=170 525). Trial quality
> was generally high. Heterogeneity of results was low to moderate.
> Neither the fixed-effect (relative risk 0·96, 95% CI 0·88-1·04) nor
> random-effects meta-analyses (0·90, 0·77-1·05) showed significant
> effects of supplementation with ß-carotene, vitamins A, C, E, and
> selenium (alone or in combination) versus placebo on oesophageal,
> gastric, colorectal, pancreatic, and liver cancer incidences. In seven
> high-quality trials (n=131727), the fixed-effect model showed that
> antioxidant significantly increased mortality (1·06, 1·02-1·10),
> unlike the random-effects meta-analysis (1·06, 0·98-1·15). Low-quality
> trials showed no significant effect of antioxidant supplementation on
> mortality. The difference between the mortality estimates in
> high-quality and low-quality trials was significant (Z=2·10, p=0·04 by
> test of interaction).ß-carotene and vitamin A (1·29, 1·14-1·45) and
> ß-carotene and vitamin E (1·10, 1·01-1·20) significantly increased
> mortality, whereas ß-carotene alone only tended to increase mortality
> (1·05, 0·99-1·11). In four trials (three with unclear or inadequate
> methodology), selenium showed significant beneficial effect on the
> incidence of gastrointestinal cancer.
>
> Interpretation We could not find evidence that antioxidant supplements
> can prevent gastrointestinal cancers; on the contrary, they seem to
> increase overall mortality. The potential preventive effect of
> selenium should be studied in adequate randomised trials.

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