L-carnosine, sometimes called simply carnosine, is a combination of two amino acids, alanine and histidine. Your body manufactures carnosine, found in high concentrations in skeletal muscle, the lenses of the eyes, the brain and the nervous system. Carnosine acts as an anti-oxidant, a substance that neutralizes free radicals, which damage cells. There’s no set dose for carnosine supplementation, since the benefits have not yet been established through clinical trials, although some studies have noted benefits in certain areas. Carnosine has no significant side effects.
A study of 31 children conducted by the Autism and Epilepsy Specialty Services of Illinois by lead author Michael Chez, M.D. reported in the November 2002 “Journal of Child Neurology” that treatment with carnosine for eight weeks improved performance on several tests that measure autistic behaviors. The study was a double-blind study, meaning that it wasn’t known which children received the supplement and which received the placebo. Children who received the placebo made no gains. Based on this study, Dr. Chez surmised that carnosine may improve neurologic function.
Although a number of published papers, such as one published in “Science of Aging Knowledge Environment” in May 2005 by lead author V. Prakash Reddy of the University of Missouri, acknowledge the potential for carnosine to improve symptoms of Alzheimer’s disease, actual studies on the benefits are still lacking. Reddy bases potential benefits on the fact that carnosine inhibits advanced glycation end products, called AGEs, which contribute to Alzheimer’s disease. Well-designed studies may eventually establish a definite benefit for treating and preventing Alzheimer’s disease.
A study published in “Biochemistry “on May 14,2009, found that in rat lenses exposed to substances that induce cataract formation and carnosine, carnosine prevented or reversed cataracts. Lead author Francesco Attanasio of the Institute of Biostructures and Bioimaging in Italy suggests that decreased carnosine levels in the lens as a result of aging may contribute to cataract formation. More human studies are needed to establish a definite benefit for carnosine use in cataracts. A study conducted by lead author Mark Babizhayev MA, PhD, of Innovative Vision Products reported an improvement in vision in a test group of 49 people with senile cataracts in "Drugs R.D." in 2002 using eye drops containing carnosine, but since his company manufactures and sells the drops, more clinical trials with larger population groups are needed to establish definite benefit.
One study reported in “Nutrition” in 1998 by lead author P.R. Roberts of the Bowman Gray School of Medicine of Wake Forest University found that adding carnosine to post-surgery diets administered via feeding tubes into the small intestine improved wound healing in rats. The benefits for human healing after surgery haven’t been established.