A member of the carotenoid family of antioxidants with provitamin A activity. The vitamin A activity of beta-carotene in food is approx. 1/12 that of retinol (pre-formed Vitamin A). Beta-carotene is most abundant in orange/yellow vegetables and fruits, such as carrots, pumpkin and winter squash.
For more information, see the beta-carotene review in the Vitamins and Minerals section.
Also known as L-alanyl-L-histidine. A naturally-occurring dipeptide in muscle tissue. Carnosine has antioxidant activity and can inhibit the formation of harmful advanced glycation end products. Carnosine also helps to buffer hydrogen ions produced during exercise, and thus delay fatigue.
A non-protein amino acid that’s a precursor to carnosine (beta-alanyl-l-histidine). Carnosine is a dipeptide that’s highly concentrated in muscle tissue. It has antioxidant effects, and acts to buffer hydrogen ions produced during exercise, thus delaying muscle fatigue. Beta-alanine is marketed primarily as a bodybuilding, performance enhancing-supplement. See Paul’s review of H+Blocker, for more information.