1. The concentration of taurine in the diets, plasma, urine and breast milk were measured in vegans and ageand sex-matched omnivore controls. Plasma and urinary amino acid concentrations were also determined.2. Taurine was absent from the vegan diet and occurred in variable amounts in the diets of the omnivores. Urinary taurine levels were less than half those of the omnivores but plasma and breast-milk levels were only slightly lower.3. Dietary energy intakes were similar in the vegans and omnivores, but protein intakes tended to be lower in the vegans.

The metabolism by the fetal rat of [1–¹⁴C] linoleic acid (18:2 n-6) was compared with that of [1–¹⁴C] α-linolenic acid (18:3 n-3) studied in vivo and in vitro. Both linoleic and α-linolenic acid were rapidly converted to long-chain derivatives in fetal brain but rates of Δ6 desaturation were higher for α-linolenic than for linoleic acid. In the liver α-linolenic, but not linoleic acid, was rapidly converted to long-chain derivatives in vivo. Measurements of Δ6 and Δ5 desaturation by fetal liver in vitro showed significant desaturase activity but this was lower than in the brain. It is suggested that the observed difference in the hepatic metabolism of linoleic compared with that of α-linolenic acid reflects their differing affinities for alternative metabolic pathways.

No abstract

No abstract