Carnosine Simply Explained

1. What It Is About

Carnosine is a small building block made of two amino acids, that is, two protein building blocks. It consists of beta-alanine and L-histidine. The body produces it itself, mainly in the muscles, and there it is easily measurable. The enzyme carnosine synthase is responsible for this production. In addition to carnosine, there is a related form called anserine, which was examined together with carnosine in several studies. Research mainly discusses three properties: carnosine can bind aggressive molecules that can damage cells. It acts as an antioxidant, that is, as protection against damaging oxygen. And it can prevent proteins from having sugar attach to them and causing them to stick together. These three points explain why carnosine is being investigated in such different areas: in metabolism, memory, muscles and the cardiovascular system. One point is important for all studies: what is ingested is not the same as what is measured in the tissue. An enzyme called carnosinase cleaves ingested carnosine in the blood. How much of it reaches the muscles unchanged depends on this breakdown. This is why research more frequently supplies the building block beta-alanine, because it increases the carnosine content in the muscle.

2. What Studies Show

The clearest findings are in children with kidney damage due to diabetes. In a study with 90 children, participants received carnosine or a placebo, that is, a sham preparation without active ingredient, over 12 weeks. In the carnosine group, the long-term blood sugar value, protein excretion in the urine and a measurement value for oxidative stress decreased, while the protective capacity against oxidative stress increased. No adverse reactions due to the carnosine administration were reported 3. In cancer treatment there is an indication of protection against nerve damage. 65 patients received chemotherapy, some of them additionally L-carnosine. In the carnosine group, 40 % of the patients remained without nerve damage; without carnosine the figure was 3.2 %. Two inflammatory messengers in the blood also decreased 5. The study is small in scale, and the authors themselves describe it as a pilot study. In memory, a study examined 39 healthy older people over 3 months. They received a mixture of anserine and carnosine or a placebo. In the group with the mixture, delayed verbal recall was preserved, that is, the ability to remember words and stories after a while. In addition, inflammatory messengers in the blood decreased 2. Because a mixture was tested, it is not possible to deduce what carnosine alone achieves. In metabolism, a small study with 15 overweight, non-diabetic persons over 12 weeks showed that the rise in fasting insulin and insulin resistance was weaker under carnosine 1. The authors themselves call the study a pilot study with a small group size. In heart failure, the walking distance in the 6-minute walk test and quality of life improved in one study 4. In autistic children, sleep improved in one study; the severity of autism did not change 6. An important observation concerns absorption: of 25 healthy persons, only 8 showed a measurable increase in the blood after a single carnosine dose 7. In the others, the cleaving enzyme in the blood was more strongly represented.

3. What Remains Unclear

Many human studies only observe and measure blood values. A measurement value, however, is not the same as the course of a disease. A lowered laboratory value does not automatically mean that the person feels better. The question of absorption is also open. Ingested carnosine is cleaved in the blood, and how much reaches the tissue unchanged varies from person to person. The better investigated route runs via the building block beta-alanine. Several studies test mixtures, for example anserine with carnosine or combinations with zinc, chromium or plant extracts. From a mixture it is not possible to deduce an effect of the single substance carnosine. Some of the studies also come from cell culture and animal experiments; such results count as preclinical, that is, as a preliminary stage, not as evidence in humans.

4. What This Means in Everyday Life

Carnosine is a substance that the body produces itself and that is being investigated in many areas. Anyone reading a report about carnosine can ask three questions: which substance was supplied? What was measured? And was a single substance or a mixture tested? These three questions determine how much weight a statement carries. The human findings are predominantly indications, not confirmed proofs. The best documented are changes in measurement values, for example in children with diabetic kidney damage. For memory, heart failure and sleep there are smaller studies with encouraging results. The next step would be to clarify how much supplied carnosine actually reaches the tissue unchanged and whether the single substance carnosine alone causes the observed changes. As long as this remains open, every assessment stays provisional.

All Details with Study Numbers and Sources: detailed page on carnosine. For children: carnosine for children.