14 replies to this topic

[Ichoose2live]

« Copenhagen, Denmark - The largest analysis of data on antioxidant vitamins ever conducted has shown that beta-carotene, vitamin A, and vitamin E probably increase mortality [1]. Two other antioxidant substances—vitamin C and selenium—had no effect on mortality. The meta-analysis of 68 randomized trials with a total of 232 606 participants, published in the February 28, 2007 issue of the Journal of the American Medical Association, was conducted by a group led by Dr Goran Bjelakovic (Copenhagen University Hospital, Denmark).

Coauthor Dr Christian Gluud (Copenhagen University Hospital) commented to heartwire: "This is the most comprehensive collection of data on antioxidant vitamins ever conducted, and we have shown that on the whole these agents have no benefit. Indeed, vitamin A, vitamin E, and beta-carotene are associated with an increase in mortality at the doses studied. Vitamin A and beta-carotene seem to have a dose-related effect, with mortality increasing as doses increase, whereas vitamin E does not appear to have a dose-related effect, with all doses associated with increased mortality." »

http://www.theheart....ticle/773375.do

Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis.
Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C.

The Cochrane Hepato-Biliary Group, Copenhagen Trial Unit, Center for Clinical Intervention Research, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. goranb@junis.ni.ac.yu

Erratum in:

• JAMA. 2008 Feb 20;299(7):765-6.

Comment in:

• JAMA. 2007 Jul 25;298(4):400-1; author reply 402-3.
• ACP J Club. 2007 Jul-Aug;147(1):4.
• JAMA. 2007 Jul 25;298(4):401; author reply 402-3.
• JAMA. 2007 Jul 25;298(4):401-2; author reply 402-3.
• Nutr Cancer. 2008;60(1):1-6.
• JAMA. 2007 Jul 25;298(4):400; author reply 402-3.

Abstract
CONTEXT: Antioxidant supplements are used for prevention of several diseases.

OBJECTIVE: To assess the effect of antioxidant supplements on mortality in randomized primary and secondary prevention trials. DATA SOURCES AND TRIAL SELECTION: We searched electronic databases and bibliographies published by October 2005. All randomized trials involving adults comparing beta carotene, vitamin A, vitamin C (ascorbic acid), vitamin E, and selenium either singly or combined vs placebo or vs no intervention were included in our analysis. Randomization, blinding, and follow-up were considered markers of bias in the included trials. The effect of antioxidant supplements on all-cause mortality was analyzed with random-effects meta-analyses and reported as relative risk (RR) with 95% confidence intervals (CIs). Meta-regression was used to assess the effect of covariates across the trials.

DATA EXTRACTION: We included 68 randomized trials with 232 606 participants (385 publications).

DATA SYNTHESIS: When all low- and high-bias risk trials of antioxidant supplements were pooled together there was no significant effect on mortality (RR, 1.02; 95% CI, 0.98-1.06). Multivariate meta-regression analyses showed that low-bias risk trials (RR, 1.16; 95% CI, 1.04[corrected]-1.29) and selenium (RR, 0.998; 95% CI, 0.997-0.9995) were significantly associated with mortality. In 47 low-bias trials with 180 938 participants, the antioxidant supplements significantly increased mortality (RR, 1.05; 95% CI, 1.02-1.08). In low-bias risk trials, after exclusion of selenium trials, beta carotene (RR, 1.07; 95% CI, 1.02-1.11), vitamin A (RR, 1.16; 95% CI, 1.10-1.24), and vitamin E (RR, 1.04; 95% CI, 1.01-1.07), singly or combined, significantly increased mortality. Vitamin C and selenium had no significant effect on mortality.

CONCLUSIONS: 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.

http://www.ncbi.nlm....pubmed/17327526

Edited by Ichoose2live, 15 March 2011 - 11:46 PM.

[triplecrown]

I'm no expert, but I believe it's been known for sometime that too much beta-carotene is not good (I read something like amounts over 15000 to 20000 ius per day). Vitamin A interferes too some extent I think with vitamin d absorption, and if I had to choose between the two I would go for vit d.

I think the problem with e is mainly the form most people take( d-alpha tocopherols). Alpha tocopherols interfere with gamma and toctotrienols which may be much more superior. I would like to find out which form they used on the study. I bet 100% it was not tocotrienols, gamma tocopherols, or vitamin e succinate.
Just my .02$

[Logan]

I'm no expert, but I believe it's been known for sometime that too much beta-carotene is not good (I read something like amounts over 15000 to 20000 ius per day). Vitamin A interferes too some extent I think with vitamin d absorption, and if I had to choose between the two I would go for vit d.

I think the problem with e is mainly the form most people take( d-alpha tocopherols). Alpha tocopherols interfere with gamma and toctotrienols which may be much more superior. I would like to find out which form they used on the study. I bet 100% it was not tocotrienols, gamma tocopherols, or vitamin e succinate.
Just my .02$

I think you have it the wrong way, vitamin A, likely in the form of palmitate, causes issues and beta carotene does not.

Fuck an A man, this is such bullshit. There is no way these antioxidants at normal doses found in a healthy diet contribute to earlier death. Very very bad post.

[Destiny's Equation]

Fuck an A man, this is such bullshit. There is no way these antioxidants at normal doses found in a healthy diet contribute to earlier death. Very very bad post.

Perhaps Ichoose2live was playing the devil's advocate or giving us food for thought.

[Sillewater]

I think you have it the wrong way, vitamin A, likely in the form of palmitate, causes issues and beta carotene does not.

Fuck an A man, this is such bullshit. There is no way these antioxidants at normal doses found in a healthy diet contribute to earlier death. Very very bad post.

Reference for your first claim quoted above?

The study was about supplements, not RDA intakes I assume.

[J. Galt]

Fuck an A man, this is such bullshit. There is no way these antioxidants at normal doses found in a healthy diet contribute to earlier death. Very very bad post.

Perhaps Ichoose2live was playing the devil's advocate or giving us food for thought.

Agreed. Opposing viewpoints are both healthy and appreciated.

[Gerald W. Gaston]

Any study that old pertaining to supplementation has likely been discussed here before... and what do you know, here are a few said threads:

http://www.longecity...ases-mortality/
http://www.longecity...rten-your-life/
http://www.longecity...-meta-anaylsis/

[8bitmore]

If anyone has access to full study it would be interesting to have the references for those "68 randomized trials" so that they may each be analyzed separately.

I do not give a hoot about meta studies like this one: there are literally 1000s of studies on these vitamins and depending on which you choose to use for a meta-study you can make it seem like the standard vitamins (A, C, E, Selenium & Beta-Carotene) are a leading cause of death world-wide OR that they make you live forever-after in happy bliss. Neither is probably especially true.

@frankbuzin; agree, its been covered before, why new thread?

[mikeinnaples]

What kind of E vitamin ?

I love studies are blurbs from articles that say 'vitamin E' without specifying the type and quantities used. I have to wonder if it is ignorance, a lazy way of saying d-alpha-tocopherol, or if they are purposefully trying to lump all the pherols and trienols together (which is absolutely wrong).

[Logan]

Fuck an A man, this is such bullshit. There is no way these antioxidants at normal doses found in a healthy diet contribute to earlier death. Very very bad post.

Perhaps Ichoose2live was playing the devil's advocate or giving us food for thought.

I overreacted. Still, we need more of an explanation.

« Copenhagen, Denmark - The largest analysis of data on antioxidant vitamins ever conducted has shown that beta-carotene, vitamin A, and vitamin E probably increase mortality [1]. Two other antioxidant substances—vitamin C and selenium—had no effect on mortality. The meta-analysis of 68 randomized trials with a total of 232 606 participants, published in the February 28, 2007 issue of the Journal of the American Medical Association, was conducted by a group led by Dr Goran Bjelakovic (Copenhagen University Hospital, Denmark).

Quotes like this are misleading. Also, they say "probably" increase mortality. I just find it hard to believe that a little extra naturally sourced beta-carotene and vitamin E in supplementation is going to have any appreciable impact whatsoever on mortality.

[nameless]

Odd that such an old study is brought up now.

But anyway, it's supplements being studied, not RDA levels from food.

There is also that big vitamin E meta study done years ago, showing similar results. But levels up to 50IU of Alpha were shown to improve mortality (if I recall right), 100IU or so being neutral, and higher doses causing a problem. So displacement of gamma seems possible there.

Several rather well-known beta carotene studies have been done, showing an increase in cancer rates in smokers. Large doses of beta carotene has been shown to cause lung issues in ferrets, smoking or not. However, lowish doses were shown to have some benefits

In my opinion, it's about dosage, forms and not throwing everything out of balance. So long as you are around RDA levels, ideally from food or at least good supplement forms, I wouldn't worry.

[Logan]

Several rather well-known beta carotene studies have been done, showing an increase in cancer rates in smokers. Large doses of beta carotene has been shown to cause lung issues in ferrets, smoking or not. However, lowish doses were shown to have some benefits

Haven't recent studies shown that food sources of vitamin A may play a significant role in cardiovascular health and lung cancer prevention? Maybe the evidence was for vitamin A/beta-carotene for cardiovascular disease. I'm having trouble finding sources.

[Mind]

Huge kudos to Frankbuzin for linking to previous Imminst discussions about this topic. I am not a big fan of meta-analyses, and there are known effects of different Vitamin E forms that confound the results, however, there is enough evidence that it should be common-knowledge that more is not always better when it comes to vitamins. That is one of the reasons why Vimmortal was designed a little "light" compared to other multi's. Imminst members are ahead of the curve and have been discussing these issues for nearly a decade, as Frankbuzin reminds everyone.

[tomas]

This type of study has been performed beforea nd heavily scrutinized.

Check this out:

http://search.lef.or...eases mortality

[medievil]

This is not very suprising.