Serum concentrations of carotenoids, alpha-tocopherol, fatty acids, and lipid peroxides among Japanese in Japan, and Japanese and Caucasians in the US

Serum concentrations of carotenoids, alpha-tocopherol, fatty acids, and thi obarbituric acid-reactive substances (TBARS) were measured in 217 Japanese residents of Japan, and in 99 Japanese and 100 Caucasian residents of the U S, aged from 50 y to 74 y. In females, serum values of carotenoids such as 13-carotene (BC) and zeaxanthin & lutein (ZL) were highest among Japanese i n Japan, followed by Japanese in the US and Caucasians in the US. In males, these values, except for serum BC values, were also highest among Japanese in Japan. Moreover, serum values of n-3 polyunsaturated fatty acids (n-3PU FAs) such as eicosapentaenoic acid and docosahexaenoic acid were significan tly higher among Japanese in Japan than among Japanese and Caucasians in th e US in both sexes. In contrast, serum values of n-6 polyunsaturated fatty acids such as linoleic acid and arachidonic acid were lowest among Japanese in Japan. For women, serum levels of n-9 unsaturated fatty acids were lowe st among Japanese living in Japan. Serum TBARS values were highest among Ja panese in Japan, followed by Japanese in the US and Caucasians in the US. A significant positive Correlation was observed between serum values of TEAR S and n-3 PUFAs among Japanese both in Japan and in the US. Serum TEARS val ues showed a significant inverse relationship with the serum values of BC a nd ZL among Japanese in Japan and with those of BC among Japanese in the US . These relationships were not always observed among Caucasians in the US. The results of this study suggest that the high TEARS values among Japanese in Japan may depend in part on lipid peroxidation induced in vitro by n-3P UFAs, while high reduction of lipid peroxidation could be expected among Ja panese in Japan with high antioxidants such as BC and ZL. In conclusion, serum levels of nonprovitamin PI carotenoids such as ZL may be a useful intake marker of vegetables, Dietary intakes of dark green vege tables and fish rich in n-3PUFAs might be more important in the prevention of some sites of cancer and of ischemic heart disease.