What is it?

Carnosine is a small molecule composed of the amino acids, histidine and alanine. It is found in relatively high concentrations in several body tissues—most notably in skeletal muscle, heart muscle, and brain.^{1 2}

The exact biological role of carnosine is not completely understood, but numerous animal studies have demonstrated that it possesses strong and specific antioxidant properties, protects against radiation damage, improves the function of the heart, and promotes wound healing.^{3 4 5 6 7 8} Carnosine has been suggested to be the water-soluble counterpart to vitamin E in protecting cell membranes from oxidative damage. Other suggested roles for carnosine include actions as a neurotransmitter (chemical messenger in the nervous system), modulator of enzyme activities, and chelator of heavy metals (i.e., a substance that binds heavy metals, possibly reducing their toxicity).

Based primarily on preliminary research from Russia, carnosine has been claimed to lower blood pressure, improve the functioning of the immune system, promote wound healing, and exert anticancer effects. However, additional research is needed before these claims can be considered scientifically well documented.

The best-documented application of carnosine is in peptic ulcers. Experimental animal studies have shown that a zinc salt of carnosine exerts significant protection against ulcer formation and promotes the healing of existing ulcers.^{9 10} However, because zinc by itself has been shown to be helpful against peptic ulcer, it is not known how much of the beneficial effect was due to the carnosine.^{11 12} Clinical studies in humans demonstrated that this compound can help eradicate Helicobacter pylori, an organism that has been linked to peptic ulcer and stomach cancer.¹³ When 60 patients suffering from dyspepsia with H. pylori infection were given either antibiotics alone (lansoprazole, amoxicillin, and clarithromycin) or antibiotics plus zinc carnosine for seven days, better results were seen in the group receiving zinc carnosine (94% eradication rate vs. 77%). The zinc salt of carnosine (in combination with sodium alginate) has also shown to be effective in severe gingivitis caused by cancer chemotherapy.¹⁴

In a preliminary trial, supplementation with a zinc salt of carnosine enhanced the response to interferon therapy in patients with chronic hepatitis C.¹⁵ It is not known whether this benefit was due primarily to the zinc or the carnosine, or whether other forms of carnosine would have the same effect.