Use of antioxidants cannot prolong life

The vitamin industry has long been famed for its anti-oxidants that improve health by compensating for dietary deficiencies. But synthesizing recent studies does not provide any evidence that these nutritional supplements can prolong life. Worse, scientists say some anti-oxidants also increase the risk of bad health.

Critics want more regulations for the nutritional pharmaceutical industry, but an antioxidant drug researcher working with the US Department of Agriculture said the call for tight control more closely exceeded the conclusions of the synthesis study.

Analysis of 67 studies showed that additional antioxidants did not reduce mortality, some drugs containing vitamin A, beta-carotene and vitamin E even increased the death rate. The research has collected evidence from 200,000 users.

Co-author Dr. Christian Gluud said: 'The harmful effects of antioxidant supplements are not due to vitamin A. Our analysis also proves quite convincing that beta-carotene and vitamin E are factors. increase death rate compared to tranquilizers'.

This comprehensive study was published in the current issue of The Cochrane Library - a publication of The Cochrane Collaboration (an international organization that evaluates medical research). The system assessment provides conclusions based on concrete evidence of medical applications after studying the content and quality of existing medical testing.

Most people don't eat enough fruits and vegetables to make sure they have enough essential nutrients. However, it is unclear whether the supplement has the same benefits as a healthy diet and whether some of the antioxidants are harmful. Anti-oxidants such as vitamin E, vitamin C or beta-carotene are still available for sale against the harmful effects of oxygen in the body.

Combining recent studies does not provide any evidence that these nutritional supplements can prolong life.(Photo: iStockphoto / Marcela Barsse)

Comprehensive reviews include studies for healthy adults and those diagnosed with certain specific medical conditions. The authors exclude studies conducted with children, pregnant women or studies evaluating supplements as a drug to treat certain acute diseases such as malignant neoplasm. Studies on the use of these drugs to complement nutritional deficiencies have also been excluded.

Gluud - associate professor and dean of the Copenhagen Trial Unit at the Center for Treatment Intervention Research, and Copenhagen University Hospital (Denmark) - said: The authors made the evaluation recommended. impose stricter regulations on antioxidant supplements, and 'call for emergency policies'.

'We need to call on policy-making experts to bravely make rules for this industry without being financially dependent on it.'

But nutrition scientist expert Jeffrey Blumberg - said the experts went too far when suggesting more stringent regulations for antioxidant supplements were required. Blumberg said, 'The report does not have any assessment of the enforcement of regulations, effectiveness or assessment of public health policies, procedures or perspectives.'

Blumberg is the director of the antioxidant drug research laboratory at the USDA Nutrition Research Center and human aging, and a professor of collaboration with Tufts University's Friedman School of Nutrition and Policy Sciences. He did not participate in a comprehensive evaluation study.

The commercial group of complementary drug manufacturers questioned the conclusions of the general assessment as well as the selection process for analysis.

Dr. Andrew Shao - vice president of the Trade Council for Vitamin Manufacturers (a trade association in Washington, DC - USA) undertakes scientific tasks and speech policy: '405 research There was no death case excluded from the meta-analysis. If these studies are taken into account, it is certain that the conclusions will be changed. '

Shao also insisted that antioxidant supplements are a safe source of health for a healthy diet. According to Shao, the above-mentioned general study only takes into account cases of death.

Gluud excuses its approach to taking into account only large-scale randomized controlled trials to assess mortality rates is necessary. Most of the non-fatal test cases are not 'regular preventive test cases'.

Blumberg is concerned with taking death for any cause as a criterion for assessing the effects of antioxidants on human health and life. The causes of this death can be anything from cancer to car accident.

Blumberg said: 'There is no biological facility that assumes that one or more of these nutrients can cause death because of any or all possible ways of doing it.'

Reference: Bjelakovic G, et al.Anti-oxidant supplements prevent death in healthy people as well as patients with many different diseases (Summary).
Cochrane Database of Systematic Reviews 2008, Issue 2.