Carotenes are a part of category of compounds found in plants (carotenoids) which have antioxidant activity. The current theory of aging is based on oxidative stress, which is why many people take daily antioxidant supplements to help reduce oxidative processes and hopefully live longer. In a recent study published in the American Journal of Clinical Nutrition (2005;82(4):879-886) researchers examined the relationship between two antioxidants and mortality in healthy elderly subjects. Over 1100 subjects enrolled in the Survey in Europe on Nutrition and the Elderly, a Concerted Action (SENECA) were employed to assess plasma levels of carotene (a- and B-carotene) and a-tocopherol (a form of vitamin E) in relation to specific causes of mortality and death from all causes.
The subjects were followed long term over the course of ten years, and the results showed that plasma carotene concentrations were inversely associated with mortality due to all causes, cardiovascular disease, and cancer (which demonstrated the strongest inverse association). Of note, was that the effect of carotene levels on death from CVD was only observed in persons with a BMI<25, which means they are not overweight. The researchers suggest this may be due to inflammatory processes which are generally lower in persons who are not overweight. It would certainly be prudent to add carotene to your daily supplement regimen, maintain your weight in a healthy range, and of course to eat a variety of colorful fruits and vegetables every day.
There are a number of studies with data on the subject of antioxidants and disease outcomes from cardiovascular disease and cancer and resultant death. Some of the evidence is conflicting, especially in regards to vitamin E. The authors of this study conducted their own meta-analysis of 5 other studies and concluded that a-tocopherol did not reduce all-cause mortality, as was observed in this study and may be unsafe at high doses. However, another study published in 2005 determined from meta-analysis of previous work that vitamin E is safe to be used long term in doses up to 2000mg per day with no increased risk of death due to cardiovascular disease. Although this study did not show benefit in prevention of mortality from vitamin E levels, the book is not closed on the subject, and as it has been deemed safe to use long term, there is no reason to discontinue vitamin E supplements in light of this study.
Posted by Kristopher Foster on March 21, 2006 04:02 PM
