Feb 26, 2007

Antioxidant Supplements Raise Death Risk

Study Shows No Benefit, Slightly Higher Death Risk For Antioxidant Supplements

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(WebMD)  Use of the popular antioxidant supplements beta-carotene, vitamin E, or vitamin A slightly increases a person's risk of death, an overview of human studies shows.

The study also shows no benefit — and no harm — for vitamin C supplements.
Selenium supplements tended to very slightly reduce risk of death.

Oxidative stress — caused by highly reactive "free radical" compounds circulating in the blood — is a factor in most diseases.

Antioxidants sweep up these free radicals. It seems to be a no-brainer that
taking antioxidant supplements would protect your health. But it may not be
that simple.

A new, detailed analysis of human studies of beta-carotene, vitamin A, and
vitamin E shows that people who take these antioxidant supplements don't live any longer than those who don't take them. In fact, those who take the
supplements have an increased risk of death.

The finding, reported in The Journal of the American Medical
Association, comes from Goran Bjelakovic, M.D., DrMedSci, of the University of Nis in Serbia; Christian Gluud, M.D., DrMedSci, of Copenhagen University Hospital in Denmark; and colleagues.

"Our findings have already changed the way I counsel my patients about
antioxidant supplements," Bjelakovic tells WebMD in an email interview.
"According to our findings, beta-carotene, vitamin A, and vitamin E cannot
be recommended. I am telling them that they should stop using these
supplements."

"There is no reason to take anything that hasn't been proven beneficial.
And these antioxidant supplements do not seem beneficial at all," Gluud
tells WebMD.

Not everyone agrees. Nutritionist Andrew Shao, Ph.D., is vice president for
scientific and regulatory affairs at the Council for Responsible Nutrition, a supplement-industry trade group.

"Consumers can feel confident in relying on their antioxidant supplements as they always have," Shao tells WebMD. "They can continue
to take them knowing they will provide the same benefits — and this article
does not change that."

Antioxidant Supplements and Death Risk

Bjelakovic, Gluud, and colleagues analyzed data from 68 randomized clinical
trials of antioxidant supplements that included 232,606 people. When they
looked at all the trials together, they found that the supplements offered no benefit but did no harm.

However, some of the trials were more exactly controlled than others. There
were 21 trials that had a "high bias risk." These trials had one or more problems with randomizing study participants to the supplement or placebo groups, with blinding both the participants and the investigators to whether
participants received supplements or placebos, and/or with following up on all participants until the end of the study.

So the researchers looked only at the 47 "low-bias-risk" studies — which included nearly 181,000 participants and which did not include people
taking selenium. They found that:

  • Taking vitamin A supplements increased the risk of death by 16 percent

  • Taking beta-carotene supplements increased the risk of death by 7 percent

  • Taking vitamin E supplements increased the risk of death by 4 percent

  • Taking vitamin C supplements did not have any effect on risk of death

  • Shao says it just isn't fair to study antioxidants in this way.

    "What these authors have done is combine studies that are incredibly
    dissimilar in all sorts of ways," he says. "These studies looked at
    different nutrients at different doses at different durations with different
    lengths of follow-up — and in different populations, ranging from folks who
    were incredibly healthy to people with cancer and other diseases."

    Moreover, Shao says, the researchers looked only at studies in which people
    died. That left out 405 clinical trials, which he says skews the results in
    favor of death risk. And he points out that the researchers original 68 studies did not show any harm from supplements.

    "These questions cause one to step back and wonder if the findings are
    relevant to the healthy population that uses these supplements to maintain
    healtand avoid chronic disease," Shao says. "That is a point they
    don't make: that antioxidants are not used to treat cancer or heart disease.
    They are used for disease prevention."

    Edgar R. Miller III, M.D., Ph.D., associate professor of medicine at Johns
    Hopkins University, in 2004 analyzed clinical trials of vitamin E. He found
    that high doses of vitamin E did more harm than good. Miller has high praise
    for the Bjelakovic/Gluud study.

    "This is a great study. It is the highest form of scientific evidence," Miller tells WebMD. "I don't think that [Shao's] criticism
    is legitimate. I argue this is the best technique to analyze all this
    information."

    Gluud and Bjelakovic strongly disagree that they "cherry picked"
    only studies that fit some preconceived conclusion. They point out that all of their methods are "transparent" and open to public view.

    "Anyone is welcome to criticize our research," Gluud says. "But
    my question is, what is your evidence? I think the parties that want to sell or use these antioxidant supplements in the dosages used in these trials, they want [to see only] positive evidence that it works beneficially."

    Advice to Consumers

    Kathleen Zelman, MPH, R.D., L.D., is director of nutrition for WebMD. She
    reviewed the Bjelakovic/Gluud study for this article.

    "This is a very comprehensive, to-be-respected analysis. This isn't just
    another study coming out," Zelman says. "The bottom line is that
    antioxidant supplements are not a magic bullet for disease prevention. We hoped maybe they were, but they are not."

    If you are interested in protecting your health, Zelman says, pills aren't
    the answer.

    "There is no single food or nutrient that is going to be the answer. The
    secret really is lifestyle," she says. "And the most important things
    about lifestyle are being at a healthy weight, being physically active, and
    eating a healthy diet."

    Shao says he's not persuaded to stop taking antioxidant supplements.

    "I take antioxidant supplements every day," he says. "I know
    more about these nutrients than most people do, including the authors of this study, who are not nutritionists. This does not change a thing for me. You can take that to the bank."

    Zelman has this advice: If you plan to continue taking antioxidant supplements, don't exceed the recommended daily doses.

    "For nutritional insurance, my suggestion would be a once-daily
    multivitamin," she says. "But for those people who take multiple
    supplements, and are going to continue to do so, heed the warning and be sure to respect the safe upper dosage limits."

    "If you are in doubt, take the time and go to your doctor and talk with
    her or him," Gluud advises.




    By Daniel DeNoon
    Reviewed by Louise Chang
    B)2005-2006 WebMD, Inc. All rights reserved.
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    Add a Comment
    by steeepe March 1, 2007 10:04 PM EST
    Some meta-analyses can be useful, especially if very similar studies are grouped together and analyzed. But grouping a bunch of primary and secondary prevention studies of various durations (mostly short) and endpoints, with huge differences in the number and characteristics of study participants and supplement doses, doesn't contribute anything useful to the literature. The criteria for designating certain studies "high risk of bias" or "low risk of bias" may be biased, and the authors don't indicate precisely why specific studies were assigned to the "high risk of bias" group. This group includes two big studies that were published in good journals, The Lancet and JNCI, that showed reductions in mortality. Also, lumping these micronutrients together under the term "antioxidants" seems misleading since they have important functions unrelated to their antioxidant properties. Would anyone consider a meta-analysis of five drugs that share one property but exert many other functions? What would be gained from such a study? Maybe the authors will increase their citation impact, but otherwise there is nothing new--no new experimental or clinical studies, just ones that have already been reported.
    Reply to this comment
    by gaye5 March 1, 2007 2:53 AM EST
    schakle I agree with you... there are to many people who have been given up by Dr's and sent home to die but after taking natural products are healed. Notice I said natural and NOT synthetic.
    In this article they also dont tell us what forms of Vitamin E or D etc that were used. Was it a mixed of Vitamin E with beta-tocopherol, delta-tocopherol, and gamma-tocopherol or just one form, were the people who they did the study on, fat, sick, older, already had problems, skinny etc, what nationality were they, were they married/single etc..
    If there is no use taking supplements then we might as well all just eat all the rubbish we want, as all natural vitamins are taken from fruit vegies etc etc..
    On the other hand we often hear of drugs killing or damaging thousands a year. How can pharmaceutical companies and Dr's do these tests when pharmaceutical drugs and Dr's are the fourth cause of death in America.. strange how nothing is done about that, mass pharmaceutical murder. We have wonderful cures now for so many things but at what cost, they have been experimenting on us for years, and does the drug that cures us then cause us to die of something else later... oh well while they are experimenting it keeps the population down...
    Reply to this comment
    by erasmus6 February 28, 2007 8:56 PM EST
    What concerns me is the millions of dollars going for these studies. One minute something is good for us and the next it isn't. Garlic, antioxidants, vitamin C, Vitamin B's, folic acid, the list is never ending. I don't think that the people doing these studies knows their *** from a hole in the ground!
    Reply to this comment
    by passerby2 February 28, 2007 2:26 PM EST
    what are we raising the chance of dying from? are we more likely to get hit by a car because we take antioxidants? jump off a building? getting shot? choking on the pills?
    Reply to this comment
    by schakle February 28, 2007 12:25 PM EST
    ***This*** ***article*** ***will*** ***not*** ***change*** ***the*** ***way*** ***I*** ***think*** ***of*** ***antioxidants***. ***I*** ***believe*** ***this*** ***is*** ***another*** ***attack*** ***from*** ***Big*** ***Pharm***. ***I*** ***would*** ***like*** ***to*** ***know*** ***who*** ***these*** ***doctors*** ***work*** ***for*** ***and*** ***if*** ***they*** ***reciever*** ***moneys*** ***froms*** ***recently***.
    Reply to this comment
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