American Journal of Clinical Nutrition, Vol 37, 918-923, Copyright © 1983 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Dietary cholesterol decreases the serum level of zinc: further evidence for the positive relationship between serum zinc and high-density lipoproteins

SI Koo and JS Ramlet

The previous finding (Am J Clin Nutr 1981;34:2376-81) that the serum level of high-density lipoprotein (HDL) cholesterol is positively correlated with the serum concentration of zinc (r = +0.81; p less than 0.01) led us to evaluate further the zinc-HDL relationship as affected by dietary cholesterol. The two diets, one control diet containing no cholesterol and the other containing 1% cholesterol, were isocalorically formulated with an equal but adequate level of zinc. Cholesterol feeding produced a significant decrease in the serum level of HDL cholesterol at 8th wk of dietary treatment and a significant increase in very low density lipoprotein cholesterol at 4th and 8th wk. At the same intervals of dietary treatment, significant decreases in serum zinc levels were observed in cholesterol-fed rats; no changes were noted in the serum levels of other related elements such as copper, calcium, and magnesium. Linear regression analysis of the 44 pairs of serum HDL and zinc values revealed a significant positive correlation (r = +0.57; p less than 0.01) between the two parameters. The rather selective lowering of serum zinc due to cholesterol feeding and the observation of the positive serum zinc-HDL relationship observed in the present and previous studies warrant further investigation into the role of zinc in cholesterol and high-density lipoprotein metabolism.