Taurine (2-aminoethanesulphonic acid) is a non-essential amino acid but not one found in proteins. The body synthesises taurine in the liver and is found in most tissues such as skeletal muscle and brain. It is added as a functional ingredient into energy drinks and is generally sourced from meat, shell fish and fish. It was originally found in bull’s bile.
There are not a great many studies which categorically demonstrate its functional benefits but it is popularly linked to nutritional energy use. The key function is to help in the transport of sodium, potassium and possibly calcium and magnesium ions across cell membranes. It may also act as an electrical buffer across these membranes. being a sulphur-containing amino acid, it is used in phase II detoxification pathways and as a precursor for bile acid production. The sulphation pathway is needed for the metabolism of steroidal hormones and alcohol. A deficiency of taurine is an issue for vegetarians if certain food groups are missing, Low levels of homocysteine, cysteine and vitamin B6 are associated with low taurine levels.
Studies cautiously dismissed it as an antioxidant ‘in vivo’ (Aruoma et al., 1988) but it was linked to neural development and the regulation of blood tonicity (water levels) and mineral content. It may help minimise liver damage in those suffering hepatitis and non-alcohol steatohepatitis.
The association with sports/energy drinks began when studies demonstrated taurine supplementation improved physical performance. Primarily, it might be involved in adipose fat regulation, helping with resting metabolism and general energy production.
One study (Baum and Weiss, 2001) showed how both taurine and caffeine in a beverage affected the performance of the heart in thirteen fit, endurance athletes. For statistical rigour, each athlete performed three sets of endurance exercises in a double-blind, crossover study. They drank before each exercise either a beverage with both taurine and caffeine, a beverage containing caffeine only, and a placebo (no caffeine or taurine). Echocardiograph measurements to monitor heart performance were made before the drinks were given, then 40 minutes following drinking but before exercise, and then after exercise in the regeneration period. The research showed that the heart’s stroke volume and its ventricular performance (diastolic intake velocity) significantly increased when both caffeine and taurine were ingested. However, significant improvements in heart performance save for ventricular function were noted, when caffeine alone was drunk. The overall conclusion was that taurine with caffeine improved heart performance. The study however did not demonstrate whether taurine alone had a benefit and caution needs to be exercised on the conclusions when extrapolating to the larger population, given the small sample size.
There is also evidence pointing to improved cognitive (mental) functioning in combination with caffeine and glucuronolactone (Seidl et al., 2000), however this research remains to be validated. Caffeine alone may be responsible for the claimed improvements and current research is on-going to disentangle which component is more significant.
Those readers interested in developing a greater understanding of the energy drinks market and the context for ingredients such as taurine to be found in such products are refered to the recent review by Heckman et al.,(2010).
Aruoma, O.I., Halliwell, B., Hoey, B.M., Butler, J. (1988) The antioxidant action of taurine, hypotaurine and their metabolic precursors. Biochem. J. 256, pp. 251-255
Baum, M. and Weiss, M. (2001). The influence of a taurine containing drink on cardiac parameters before and after exercise measured by echocardiography. Amino Acids. 20 (1), pp. 75-82.
Heckman, M.A., Sherry, K., Gonzalez De Mejia, E. (2010) Energy Drinks : An Assessment of their market size, consumer, demographics, ingredient profile, functionality, and regulations in the United States. Comprehensive Reviews in Food Science and Food Safety, 9, p. 303-317.
Seidl, R., Peyrl, A., Nicham, R., Hauser, E. (2000) A taurine and caffeine-containing drink stimulates cognitive performance and well-being. Amino Acids 19 pp. 635-642