Estimation of Linoleate Intake of Men From Serum Lipid Analysis

Twelve young men were fed controlled diets containing three known levels of linoleate in the fat for periods of fifteen days. At the end of each diet period blood was drawn, and the serum lipids were extracted. The fatty acids of total lipids, triglycerides, phospholipids and cholesteryl esters were analyzed for their dienoic, trienoic and tetraenoic fatty acids. The algebraic sum (dienoic − trienoic + tetraenoic) was plotted against log linoleate intake, and the equations for the linear relationships were derived by the method of least squares. The best estimate of dietary linoleate was found to be the (dienoic − trienoic + tetraenoic) acids of serum triglyceride fatty acids. However, the comparable relationship for total fatty acids and dietary linoleate gave such high correlation between these variables (r = 0.90) that fractionation of serum lipids seems unjustified. The equation for this relationship is log10 linoleate = −0.296 + 0.0243 (diene − triene + tetraene). This relationship is offered as a means of estimating dietary linoleate from serum analysis. The correlation between dietary linoleate and total serum cholesterol was found to be −0.24.