Carotenoids and retinol: their possible importance in determining longevity of primate species.

Aging and cancer share a number of characteristics. This has led to the hypothesis that species' differences in longevity may be governed in part by the same mechanisms as those processes governing species' differences in their age-dependent probability of developing cancer. Much evidence has indicated that beta-carotene and retinol may be important natural anticarcinogens. Accordingly, they also may be important antiaging agents. This possibility has been tested by determining if a positive correlation exists between the concentration of carotenoids and retinol in serum and brain tissue with the maximal life-span potential of mammalian species. The results show a significant positive correlation for the carotenoids but not for retinol. These results suggest that the carotenoids may be biologically active as protective agents against cancer and as longevity determinants. Retinol appears to be less important in these functions.