Another Large Study Shows No Benefit From Antioxidant Supplementation

The idea that you can do something positive for long term health by consuming presently available antioxidant supplements is a myth, not backed up by scientific evidence at all: "A study of vitamin E and selenium use among 35,000 men found that the vitamin users had a slightly higher risk of developing prostate cancer ... A separate study of 38,000 women in Iowa found a higher risk of dying during a 19-year period among older women who used multivitamins and other supplements compared with women who did not ... The findings are the latest in a series of disappointing research results showing that high doses of vitamins are not helpful in warding off disease. ... You go back 15 or 20 years, and there were thoughts that antioxidants of all sorts might be useful. There really is not any compelling evidence that taking these dietary supplements above and beyond a normal dietary intake is helpful in any way, and this is evidence that it could be harmful. ... Everyone needs vitamins, which are essential nutrients that the body can't produce on its own. But in the past few years, several high-quality studies have failed to show that high doses of vitamins, at least in pill form, help prevent chronic disease or prolong life." Antioxidants specifically targeted to the mitochondria have been shown to produce benefits to health and life span in mice, but running out to eat antioxidants from a bottle because of that is nothing more than magical thinking. In the case of currently available antioxidant supplements, there is every reason to think that they interfere with the beneficial mechanisms of exercise, causing a net loss in long term health.



Is that true regarding Acetyl-L Carnitine and Alpha Lipoic acid? I though the reasoning behind that is that it WAS specifically targeted to the mitochondria in humans and mice. Just more hogwash?

Posted by: Matt at October 17th, 2011 6:21 AM

I have a few points to make regarding this. First of all, the only citation I found was this: and it doesn't discuss Vit. E and selenium. Any links where I can find more information on this? There's nothing on PubMed and I would like to read more about this.

As for studies, the second one was done in older women, despite the fact that healthy diet and supplementation is always better as a prevention - not a cure. Thus, starting to supplement your diet with vitamins at older age is pointless, so this research, IMO, was a waste of time and money.

Second point I wanted to make is that they tested Selenium and Vit E. on men and only with regards to prostate cancer. I far as I can see, no other cancers were studied. Now, the problem that I can see right away here is that prostate cancer, as well as breast, ovarian and cervical cancers are so-called "hormonal cancers". Most of the time, these types of cancers appear later in life due to hormonal imbalance in both men and women. It is quite obvious that antioxidants got nothing to do with such issues, so again - why waste money on such research? Selenium and Vit. E showed positive results tested on diseases which are actually relater to ROS damage, i. e. age related macular degeneration, cirrhosis, glaucoma, etc.

Posted by: Elvira at October 18th, 2011 1:21 AM

You really have to reconsider your vitamin attitude. The study with older woman and vitamins is rebutted on several places and fatally flawed. You can't just relay on presentation of the data in the media.

It turns out it was suffering from sick-user effect and that vitamins actually reduce mortality once this is taken into account. I.E. if you used vitamins before you got sick, you live longer, if you started after you are diagnosed you do not.

Furthermore, lumping all vitmains in the same category is meaningless. You can't even do that for single one - i.e. Vitamin E is complex of hundreds chemicals while the study you referenced use only 1 of those. I would be interested to know if there is such effect with mixed tocopherols.

You comment few negative studies, but if you turn up google schoolar and start digging up you will see innumerious studies, particularly those about vitamin C which show substantial benefit. For C alone there must be hundreds per year.

Posted by: majjkinetor at October 22nd, 2011 4:56 AM

Oh yes, about exercise, thats just absurd and wrong. If antioxidants were diminishing exercise adaptation, then all animals would suck at sports becuase they make gram amounts of vitamin C per day in the liver/kidney and in stress this is upregulated 10 fold.

Furtheremore, all studies are replicated with opposite conclusion. See for instance this page for details:

Posted by: majkinetor at October 22nd, 2011 5:01 AM

Matt: yes, it's true of ALCAR and lipoic acid. They've been tested repeatedly; they don't extend lifespan.

Elvira: the reason they were tested for prostate cancer specifically was because this cancer was the one for which the preliminary evidence for a protective effect of these specific antioxidants was most promising. You don't run a clinical trial against 'everything at once:' that just leads to a fishing expedition, where sheer chance is going to dictate that the intervention will seem to have had a beneficial effect on SOMETHING.

majjkinetor : the 'sick user' hypothesis has been advanced as an explanation for the negative results, but it's sheer speculation at the moment: there's no actual evidence that it played a role in the results. In fact, there is evidence that it did not: "the use of supplements was not modified by a prebaseline diagnosis of CVD, diabetes mellitus, or cancer. Furthermore, intermediate cancer did not alter the supplement-taking pattern." If anything, as they note, "The use of dietary supplements is related to healthier lifestyle"! While their data cannot absolutely rule out a 'sick user' effect, the available evidence is against it.

One can always critique any one study; the point, as Reason notes, is that there is now a massive burden of evidence to the effect that, despite promising-looking findings in short-term studies or studies of mice made sick with mutations or toxins, when given to normal people in the real world, and with a very few specific exceptions (eg, vitamin D against fractures in older women; niacin for people with low HDL and high LDL who are not taking a statin), dietary supplements -- and especially "antioxidant" dietary supplements -- don't reduce risk of disease or death.

Posted by: Michael at December 14th, 2011 10:41 AM
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