Athletic performance of some individuals, especially vegetarians, might benefit from supplementation with beta-Alanine.
Carnosine (also known as beta-alanyl-L-histidine) is a molecule made up of two amino acids, alanine and histidine. It is synthesized in animal tissues, especially muscle and brain (1), and is not contained in any plant foods. One study has shown vegetarians to have 50% or less carnosine in muscle tissue (7).
Most of the research on carnosine has been in vitro and in animal models, with a few small studies conducted in humans. Most of the research has looked at carnosine as an anti-glycation/anti-glycosylation agent and for athletic performance.
Carnosine is thought to inhibit Advanced Glycation End (AGE) products, among other glycosylation products. This could be valuable in preventing or treating a range of diseases that are affected by AGE products, such as diabetes and diseases that can be caused by diabetes such as cataracts. Alzheimer's disease and Parkinson's might also be improved by carnosine. At present (2009), these therapies are in their infancy and I would not start supplementing with carnosine until more is known.
Beta-alanine is the limiting amino acid for carnosine synthesis, and beta-alanine supplements have been shown to increase muscle levels of carnosine. In fact, only beta-alanine supplements, rather than carnosine supplements, have been tested on athletic performance in human subjects.
In the American College of Sports Medicine's 2009 position paper on nutrition and athletic performance, beta-alanine was not mentioned in the list of supplements which perform as claimed (5). Despite this, about half a dozen studies have shown that about 6 g of beta-alanine, taken in doses spread out throughout the day, for 4 or more weeks, results in improved ability to perform, particularly during bouts of cycling (2, 6). Not all studies have shown a significant benefit (3, 4).
In comparison with creatine, there has been very little testing of beta-alanine supplementation. There have been some reports of mild and infrequent parathesia (tingling or numbness). It appears to be safe in amounts of 6 g per day for up to 10 weeks.
1. Hipkiss AR. Glycation, ageing and carnosine: are carnivorous diets beneficial? Mech Ageing Dev. 2005 Oct;126(10):1034-9. Review.
2. Hill CA, Harris RC, Kim HJ, Harris BD, Sale C, Boobis LH, Kim CK, Wise JA. Influence of beta-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity. Amino Acids. 2007 Feb;32(2):225-33. Epub 2006 Jul 28.
3. Derave W, Ozdemir MS, Harris RC, Pottier A, Reyngoudt H, Koppo K, Wise JA, Achten E. beta-Alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters. J Appl Physiol. 2007 Nov;103(5):1736-43. Epub 2007 Aug 9.
4. Kendrick IP, Harris RC, Kim HJ, Kim CK, Dang VH, Lam TQ, Bui TT, Smith M, Wise JA. The effects of 10 weeks of resistance training combined with beta-alanine supplementation on whole body strength, force production, muscular endurance and body composition. Amino Acids. 2008 May;34(4):547-54. Epub 2008 Jan 4. (Abstract)
5. American Dietetic Association; Dietitians of Canada; American College of Sports Medicine, Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009 Mar;41(3):709-31. Review. PubMed PMID: 19225360.
6. Smith AE, Walter AA, Graef JL, Kendall KL, Moon JR, Lockwood CM, Fukuda DH, Beck TW, Cramer JT, Stout JR. Effects of beta-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. J Int Soc Sports Nutr. 2009 Feb 11;6:5.
7. Harris RC, Jones G, Hill CA, et al. The Carnosine Content of V Lateralis in Vegetarians and Omnivores The FASEB Journal. 2007;21:769.20. (Only abstract available.)
Kendrick IP, Kim HJ, Harris RC, Kim CK, Dang VH, Lam TQ, Bui TT, Wise JA. The effect of 4 weeks beta-alanine supplementation and isokinetic training on carnosine concentrations in type I and II human skeletal muscle fibres. Eur J Appl Physiol. 2009 May;106(1):131-8. Epub 2009 Feb 12. PubMed PMID: 19214556. (Abstract)
Park YJ, Volpe SL, Decker EA. Quantitation of carnosine in humans plasma after dietary consumption of beef.J Agric Food Chem. 2005 Jun 15;53(12):4736-9. (Abstract)
Toh T, Morton J, Coxon J, Elder MJ. Medical treatment of cataract. Clin Experiment Ophthalmol. 2007 Sep-Oct;35(7):664-71. Review. (Abstract)