The association of lipoprotein cholesterol with vitamin A

Several studies have linked total serum cholesterol concentrations below 200 mg/dl with increased cancer risk, especially among men. Cancer risk appears to be associated primarily with low concentrations of total cholesterol and of low-density lipoprotein cholesterol but not of high-density lipoprotein cholesterol (HDL). It has been suggested that low concentrations of total cholesterol are associated with increased cancer risk indirectly by virtue of their association with low concentrations of carotene and/or retinol. The relationship between serum carotene and cholesterol in a biracial group of 146 first-year college students was investigated. White men and women had similar carotene concentrations. Blacks had higher serum carotene concentrations than whites. There was a significant relationship between carotene concentrations and total cholesterol, which was most evident in men, both black (r = +0.72; P less than 0.01) and white (r = +0.49; P less than 0.01). The correlations for the women were significant, but of lower magnitude than for the men. Significant carotene-HDL relationships were observed among black men (r = 0.31; P less than 0.05) and among women (r = 0.35; P less than 0.05 and r = 0.31; P less than 0.05, black and white, respectively). Furthermore, the women also demonstrated a significant carotene-HDL2 association. The results are consistent with the hypothesis that the association between low serum cholesterol concentrations and cancer may be the result of a relationship between lipoprotein cholesterol concentrations and vitamin A metabolism.