Serum concentrations of antioxidant nutrients in healthy American, Chinese and Korean adults.

Population variabilities of serum carotenoid and tocopherol levels using reverse-phase HPLC in healthy American (Caucasian), Chinese and Korean adults were determined. Considerable variation in serum nutrient concentrations was found among these groups. The mean serum concentration of lutein/zeaxanthin was significantly higher in the Chinese than in the white Americans (p<0.001), whereas serum α-carotene and lycopene concentrations were significantly higher in white Americans than in Chinese (p<0.001). Serum ß-carotene concentrations in Koreans were significantly higher than in either white Americans or in Chinese. The mean serum lycopene concentration in Koreans was lower than in Americans. The mean serum retinol concentration was significantly higher in white Americans than in Chinese or Koreans (p<0.005). American serum γ-tocopherol concentrations were significantly higher (p<0.005) than those of the Chinese, whereas γ-tocopherol values were significantly lower (p<0.001) than those of the Chinese. These differences probably reflect differences in dietary intakes among these population groups.