Correlates of serum lycopene in older women

Experimental and epidemiological evidence suggests that lycopene, a predomi nant carotenoid found in human serum, may reduce the risk of certain cancer s. We examined the association of dietary, physiological, and other factors with serum lycopene concentrations in a subsample of 946 postmenopausal wo men participating in the Women's Health Initiative. Pearson partial correla tion coefficients and linear regression coefficients were calculated after adjustment for age, ethnicity, and serum low-density-lipoprotein (LDL) chol esterol. Serum lycopene was correlated with serum LDL cholesterol (r = 0.23 ) and dietary lycopene (r = 0.17 both p < 0.001). Individual food items fou nd to be correlated with serum lycopene after adjustment included fresh tom atoes or tomato juice (r = 0.11), cooked tomatoes, tomato sauce, or salsa ( r = 0.17), and spaghetti with meat sauce (r = 0.19, all p < 0.01). Age and body mass index were negatively associated with serum lycopene levels (both p < 0.001). Serum lycopene levels were highest in the summer and highest f or those living in the northeastern United States. If we postulate that hig h serum lycopene levels reduce cancer risk, if becomes apparent that we hav e limited ability to detect this association from studies of lycopene intak e. An understanding of factors associated with serum lycopene levels can be useful for the interpretation of studies of dietary lycopene and disease r isk.