Taurine (2-aminoethanesulfonic acid) is produced in the pancreas of humans, but is also present in the diet in protein foods. Current understanding suggests that taurine is required for correct cardiac function, neurotransmission, for bile acid formation and for retinal function. Taurine has also become popular as a sports supplement because consumption may be required for correct neuromuscular function. Taurine is not present in proteins of vegetable origin, and therefore vegans are thought to have lower intakes of taurine when compared to vegetarians and omnivores. Researchers1 have investigated the plasma levels of taurine in vegans based on the hypothesis that intakes of taurine may be reduced in those individuals who do not consume animal protein. When plasma levels of taurine were measured, the vegans were found to have a significantly lower value compared to omnivorous control subjects (45 versus 58 µmol/L).
To confirm the lower plasma levels the researchers also measure the urinary losses of taurine and found that excretion rates of taurine were lower in vegans compared to omnivorous control subjects (266 versus 903 µmol/day). Because taurine can be manufactured in the pancreas from cysteine and methionine, they analysed the 3 day food diaries of the vegan subjects to assess intakes of these amino acids. While there was a marginal but adequate intake of both cysteine and methionine, intakes of taurine were negligible as expected. Pyridoxal 5-phosphate is also required for synthesis of taurine, and adequate intake of vitamin B6 was recorded in the diaries of the subjects. Therefore dietary taurine is required for optimal taurine status and pancreatic production does not compensate for negligible intakes of taurine. Taurine is needed nutritionally which suggests that it should be given a conditionally essential classification.
RdB
