Carnosine levels decline with age. Since carnosine acts as a pH buffer, it can keep on protecting muscle cell membranes from oxidation under the acidic conditions of muscular exertion. The body is made up largely of proteins. Unfortunately, proteins tend to undergo destructive changes as we age, due largely to oxidation and interactions with sugars or aldehydes. The high levels of carnosine in the brain may serve as natural protection against excitotoxicity, copper and zinc toxicity, protein cross-linking and glycation, and especially oxidation of cell membranes.
Animal studies show broad protective effects in simulated stroke.
New research shows that copper and zinc dramatically stimulate senile plaque formation in Alzheimer's disease. Chelators of these metals dissolve plaques in the laboratory. A signature of Alzheimer's disease is impairment of brain microvasculature. It is most fortunate that carnosine is safe at high dosages because the body would neutralize lesser amounts of carnosine. There are thought to be many mechanisms responsible for aging.