Supplementation of antioxidants could increase the risk of death

As always, NICUS (Nutrition Information Centre, University of Stellenbosch) is committed to the provision of up-to-date, credible and authoritative information in order to promote a scientifically sound nutrition culture.

Supplementation of antioxidants could increase the risk of death

A recent meta-analysis of data from 68 well conducted trials with 232 606 participants in Europe, the Americas, Asia and Australia including lower- and higher-income countries, indicate that antioxidant supplements, singly or in combination with other nutrients, given at different doses and duration increase all cause mortality. The effects of these supplements were assessed in the general adult population as well as patients with diseases such as cardiovascular, neurological, skin, renal, endocrinological, gastrointestinal and inflammatory disease

Key findings:

• Better and urgent understanding of the mechanisms and actions of antioxidants in relation to disease and disease progression is needed
• Singly or in combination with other supplements, supplementation with beta carotene increased mortality significantly
• Vitamin A supplementation in combination with other supplements, increased mortality significantly
• Vitamin E given on it's own or in combination significantly increased mortality
• Vitamin C supplementation was not found to increase mortality or longevity
• Selenium given in combination or as a single supplement was found to have no significant effect on mortality; it tended to have a protective effect, but more research is necessary to confirm this effect
• Beta carotene, vitamin A and vitamin E in single preparations or in different combinations significantly increased mortality
• This data is not relevant in populations with specific needs and confirmed deficiencies of antioxidants or other nutrients

If you think you need supplements, it would be more beneficial to consider the following:

• Make sure you are consuming an adequate diet which includes a variety of foods
• Consult an expert on the adequacy of your diet
• Avoid supplements with glamorous multi-claims which cannot be substantiated when scrutinized
• Avoid single nutrient supplements
• Check the composition of the supplement you plan to take or you are taking
• Choose a multi-vitamin, multi-mineral supplement that contains up to 2-3 times the recommended intake (see Table)
• Reassess your need to take such supplements regularly and for prolonged periods
• Report to your doctor any adverse effects you think may be linked to the supplements