The popularity of amino acids as supplemental ingredients in various dietary supplements, functional foods, and beverages has increased exponentially in the last decade, with their prevalence being highest in sports nutrition and beverages, of particular note, the original red bull. Taurine, L-glutamine and L-arginine are perhaps the three most widely used amino acids. However, despite their popularity, all essential and non-essential amino acids, are still to be subjected to a comprehensive safety review with subsequent establishment of tolerable upper intake levels, which is the case for the majority of the essential vitamins and minerals.In this article we will look at the amino acid, taurine (Tau) and its impact on health.
Taurine is a member of the family of sulfur containing amino acids that includes methionine, cysteine and homocysteine. Unlike cysteine and methionine, taurine is not incorporated into proteins, but does play a role in many important physiological functions, including bile acid conjugation, retinal and neurological development and modulation of cellular calcium levels and immune function. One of the most abundant free amino acids in the body, taurine is synthesized endogenously in the liver from cysteine via several enzymatic steps, and therefore is considered nonessential or conditionally essential. Quality dietary sources include human breast milk and animal proteins such as red meat and fish. The estimated intake from dietary sources stands at approximately 40-400 mg/day, with an observed safety level (OSL) of no greater than 3 g/day.
In recent times, several therapeutic benefits have been proposed for taurine supplementation, including the treatment of diabetes, hypertension, heart failure, retinal degeneration and skeletal muscle disorders. Moreover, knowledge of taurine's role in osmoregulation (active regulation of pressure changes pertaining to human water content), modulation of cellular calcium levels and its high concentration in muscle tissue have led to a rapid increase in the prevalence and research of taurine containing energy and sports beverages.
There have been more than 30 peer-reviewed, published human clinical trials involving taurine administration, with the most recent assessment undertaken in 2004. None of the human clinical trials to date have found a significant adverse effect related to taurine administration. However, published trials have involved oral dosages ranging from 500 mg/day to 10 g/day, well above the OSL of 3 g/day. Nonetheless, no observed adverse effects have been reported at dosages exceeding OSL.
At dosages of 3 g/day taurine has been found to:
(i) Lower heart rate at sub maximal workload in cyclist and triathletes
(ii) Significantly increase maximal oxygen uptake in cyclists and triathletes
(iii) positively influence stroke volume in cyclists and triathletes, improving endurance
time (race time) at maximum intensity.
If you have any questions relating to this post please make contact:
Newcastle Naturopath, Mark Hinchey Naturopathy, 601 Glebe Road Adamstown, NSW, Australia.