Health and Fitness Corner

Epidemiological studies have shown that eating foods rich in antioxidants results in a reduced risk of heart attacks,strokes and cancer. Antioxidants reduce damaging oxidative stress caused by highly active free radicals in the blood. These detrimental effects have been implicated as a pathogenic factor in most diseases, including cardiovascular diseases and cancer. Antioxidant rich foods include fruits, vegetables, nuts and whole grains. Phytochemicals are strong antioxidants and are naturally present in these foods. For example, soybeans contain genisten, tomatoes and grapefruit contain lycopene, cabbage and brussel sprouts cotain indoles, garlic and onion contain allylic sulfides, tea contains tannins and most fruits and vegetables are rich in flavonoids. A diet rich in these foods is highly protective. This observation has led to the widespread use of synthetic multivitamins and anti-oxidants to prevent cancer and cardiovascular diseases, and increase life span. However taking these supplements have not shown protective benefits, and have actually been harmful in most people.

Dr. Jaakko Mursu and collegues recently presented disturbing data regarding life expentancy with the use of multivitamins and mineral supplements in healthy older women. They found that most supplements in older women were associated with a higher risk of total mortality. These supplements included multivitamins, vitamin B6, folic acid, and minerals such as iron, magnesium, zinc and copper. There was a 3% to 6% increased risk of death with taking vitamin B6, folic acid, iron, magnesium, and zinc supplements and an 18.0% increased risk for total mortality with copper supplementation. The increased rates appear when compared to individuals not taking these supplements. This large study involved a total of 38,772 older women, between the ages of 55 to 69 years. Their results were published in the October 10, 2011 issue of the Archives of Internal Medicine.

In an earlier review of 47 studies involving nearly 181,000 participants, Bjelakovic and colleagues reported that taking vitamin A supplements increased the risk of death by 16%, beta-carotene by 7%, and vitamin E by 4%. These findings were published in the Journal of the American Medical Association in 2007.

Meta-analysis of several studies have also documented that antioxidants do not prevent cancer. On the contrary, studies have implicated their intake with a higher incidence of some cancers. In a study by Lawson and associates and published in the Journal of the National Cancer Institute in 2007, the risk of fatal prostate cancer doubled in men who took multivitamins seven days a week, when compared with men who did not take any multivitamin supplements. Their study involed 295,344 men enrolled in the National Institutes of Health Diet and Health Study. Other studies have shown that mortality also appears to be increased in persons with gastrointestinal and lung cancers while ingesting anti-oxidant supplements.

The exact mechanism behind this harmful effect of multivitamin/anti-oxidant supplementation is not clear. It has been suggested that supplemental antioxidants may decrease free radicals and upset defensive mechanisms necessary to destroy precancerous and cancerous cells. Synthetic antioxidants may also possess pro-oxidant properties.

The American diet provides almost 120% the recommended daily allowances for β-carotene, vitamin A, and vitamin C. Except for calcium and prescribed supplementation for documented deficiency (for example Vitamin D), scientific data suggests that most multivitamins and mineral supplements should not be used in otherwise well nourished individuals.

Dr. Shashi K. Agarwal is a Board Certified Internist and Cardiologist with a private practice in New York City and New Jersey. He is also a diplomate of the American Board of Holistic Medicine and the American Academy of Anti-Aging Medicine.

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