Seasonal changes in the relationship between serum concentration of beta-cryptoxanthin and serum lipid levels

Beta-cryptoxanthin (beta-CRX) is a carotenoid pigment found especially in Satsuma mandarin (Citrus unshiu Marc.) fruit, which is mainly produced in Japan. Previously, we found that serum beta-CRX concentrations rose to extreme levels as the frequency of consumption of Satsuma mandarin increases. Using 94 non-smoking female volunteers, the present study evaluated the relationship between serum concentration of beta-CRX and serum lipid levels in September, when the Satsuma mandarin is not in season, and in January of the next year, when it is in season. The mean of increment in serum beta-CRX concentrations from September to January was 95.9 +/- 84.0 microg/dl (mean +/- SD). Although the changes in serum lipid levels did not correlate with the changes in serum beta-CRX, the serum HDL-cholesterol and apo-lipoprotein A1 levels in the highest quartile of the increment in serum beta-CRX from September to January were significantly higher than those in the lowest quartile in both September and January. In cross-sectional analyses, serum beta-CRX concentrations were correlated positively with those of LDL-cholesterol and apo-lipoprotein B levels in September, but these correlations were not observed in January. In contrast, serum beta-CRX concentrations were correlated positively with those of HDL-cholesterol and apo-lipoprotein A1 levels in January. These results suggest that habitual eating of Satsuma mandarin while it is in season may influence lipid metabolism throughout the year.