Grass-based ruminant production methods and human bioconversion of vaccenic acid with estimations of maximal dietary intake of conjugated linoleic acids

Reports on human conjugated linoleic acids (CLAs) intake vary, and usually don't consider food production methods and vaccenic acid (VA)-induced CLA biosynthesis in humans. The aim of this review was to estimate the achievable CLA intake considering both food sources produced by feeding patterns natural to animals and human VA bioconversion. Exogenous CLA supply from milk, cheese, lamb, and beef from grass-based ruminant production methods, was calculated to be about double that of estimates based on modern production methods (respectively, from the four sources: 1.25, 1.50, 1.44, and 0.69% of total fatty acids). Using available human consumption data this resulted in an estimated achievable CLA intake (including VA bioconversion) of between 711 and 1107 mg d−1. Intake of products from natural grass-fed ruminants leads to a several-fold higher CLA food content and, along with consideration of endogenously formed CLA from VA, results in a substantially higher CLA availability than previously estimated.