Navigation Links
Antioxidant users don't live longer, analysis of studies concludes
Date:4/15/2008

The vitamin industry has long touted antioxidants as a way to improve health by filling in gaps in diet, but a new review of studies found no evidence that the nutrition supplements extend life. Worse, the review authors said that some antioxidants could increase risk for death.

The reviewers want more regulation of the nutraceuticals industry, but an antioxidant researcher with the U.S. Department of Agriculture said that call for stricter monitoring overreaches the conclusions of the review.

The meta-analysis of 67 randomized studies found that supplemental antioxidants do not reduce mortality and that some including vitamin A, beta-carotene and vitamin E could increase mortality. The review combined evidence from more than 200,000 people.

The harmful effects of antioxidant supplements are not confined to vitamin A, said review co-author Christian Gluud, M.D. Our analyses also demonstrate rather convincingly that beta-carotene and vitamin E lead to increased mortality compared to placebo.

The review appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

Most people do eat not enough fruits and vegetables to ensure an adequate intake of vital nutrients. However, it is unclear if supplementation can provide benefits akin to a healthy diet and if some antioxidants are, in fact, harmful. Antioxidants are nutrients such as vitamin E, vitamin C, or beta carotene that have been marketed as a way to counter the damaging effects of oxygen in the tissues.

The review included studies of healthy adults and adults diagnosed with specific, stable medical conditions. The authors excluded studies with children or pregnant women, or studies that evaluated supplements as treatment for acute diseases, such as malignant cancer. It also excluded studies that used supplements for replacement of nutrient deficits.

The review authors recommend greater regulation of antioxidant supplements and make a plea for urgent political action, said Gluud, director of medical science, associate professor and department head of the Copenhagen Trial Unit at the Centre for Clinical Intervention Research and Copenhagen University Hospital in Denmark.

We should request that the regulatory authorities dare to regulate the industry without being financially dependent on the very same industry, Gluud said.

However, nutrition science expert Jeffrey Blumberg, Ph.D., said the reviewers go too far in their recommendations for more stringent regulation of antioxidant supplements.

I could find nowhere in this report any review of regulatory practices and effectiveness or the evaluation of public health policies, procedures or perspectives, Blumberg said.

Blumberg is director of the Antioxidants Research Laboratory at the USDA Human Nutrition Research Center on Aging and a professor with the Friedman School of Nutrition Science and Policy at Tufts University. He was not involved in the review.

A supplement-industry trade group questions both the review conclusions and the study selection process for the analysis.

Four hundred five studies which showed no deaths were excluded from the meta-analysis, which if included, clearly would have altered the outcome of the meta-analysis, said Andrew Shao, Ph.D., vice president of scientific and regulatory affairs for the Council for Responsible Nutrition, a supplement industry trade association in Washington, D.C.

Shao maintained that antioxidant supplements are safe additions to a healthy diet.

The review only includes studies in which someone died.

Gluud defended his methodology, saying it is important to include only large, randomized controlled trials to assess mortality. Most of the trials that showed no deaths were not proper preventative trials, he said.

Blumberg raised concerns about the use of all-cause mortality as a yardstick for antioxidants influence on health and life. All-cause mortality includes deaths resulting from everything from cancer to a train wreck.

Blumberg said: There is no basis in biology to presume that one or more of these nutrients can kill through any and all possible mechanisms of action.


'/>"/>

Contact: Lisa Espoito
hbns-editor@cfah.org
Center for the Advancement of Health
Source:Eurekalert

Related biology news :

1. Mounting evidence shows red wine antioxidant kills cancer
2. Antioxidants could provide all-purpose radiation protection
3. Antioxidant to retard wrinkles discovered by Hebrew University researcher
4. Clemson chemists discover new way antioxidants fight debilitating diseases
5. Antioxidant overload may underlie a heritable human disease
6. Preliminary DNA analysis completed on California wolverine
7. Isotope analysis reveals foraging area dichotomy for Atlantic leatherback turtles
8. Surprising discovery from first large-scale analysis of biodiversity and biogeography of viruses
9. New UC analysis shows alarming increase in expected growth of Chinas carbon dioxide emissions
10. Alarming growth in expected CO2 emissions in China, finds UC analysis
11. DOE JGI releases a new version of its metagenome data management and analysis system
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/22/2016)... On Monday, the Department of Homeland Security (DHS) issued ... the Biometric Exit Program. The Request for Information (RFI), ... that CBP intends to add biometrics to confirm when ... , in order to deter visa overstays, to ... Logo - http://photos.prnewswire.com/prnh/20160622/382209LOGO ...
(Date:6/16/2016)... FRANCISCO , June 16, 2016 ... size is expected to reach USD 1.83 ... by Grand View Research, Inc. Technological proliferation and ... banking applications are expected to drive the market ... ) , The development of advanced ...
(Date:6/9/2016)... -- Paris Police Prefecture ... to ensure the safety of people and operations in several ... tournament Teleste, an international technology group specialised in ... that its video security solution will be utilised by ... safety across the country. The system roll-out is scheduled for ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... 24, 2016  Regular discussions on a range of subjects ... the two entities said Poloz. Speaking at a ... , he pointed to the country,s inflation target, which ... "In certain areas ... have common economic goals, why not sit down and address ...
(Date:6/24/2016)... NC (PRWEB) , ... June 24, 2016 , ... Researchers ... the most commonly-identified miRNAs in people with peritoneal or pleural mesothelioma. Their findings are ... to read it now. , Diagnostic biomarkers are signposts in the blood, lung ...
(Date:6/23/2016)... 23, 2016   Boston Biomedical , an ... designed to target cancer stemness pathways, announced that ... Orphan Drug Designation from the U.S. Food and ... cancer, including gastroesophageal junction (GEJ) cancer. Napabucasin is ... inhibit cancer stemness pathways by targeting STAT3, and ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
Breaking Biology Technology: