Epidemiologic evidence of a role of carotenoids in cardiovascular disease prevention.

The tremendous chemical potential of the highly conjugated double bonds in carotenoids has driven research into their protective role in cardiovascular disease development. Prevention of low-density-lipoprotein oxidation and reduction of oxidative stress at the plaque formation are popular hypotheses underlying this research. Many epidemiologic studies have examined relations between beta-carotene exposure and cardiovascular disease risk. These studies used different measures to determine carotenoid exposure: semiquantitative food-frequency questionnaires, carotenoid concentrations in serum taken before the onset of disease and analyzed after diagnosis, and carotenoid concentrations in adipose tissue. Although the epidemiologic evidence is consistent with a protective association between beta-carotene and cardiovascular disease, findings from the first single intervention trial conducted in a large free-living population cast doubts on the utility of beta-carotene for all high-risk populations. Beta-Carotene may only represent a marker of dietary behavior conductive to lower risk of cardiovascular disease. Research on other carotenoids is needed.