Carnosine is a substance produced naturally by the body. Classified as a dipeptide, a compound consisting of two linked amino acids (in this case alanine and histidine), carnosine is highly concentrated in muscle tissue and the brain. It is also present in significant concentrations in beef and fish and in lower concentrations in chicken.
In synthetic form, carnosine is sold in supplement form as a natural remedy for a variety of health conditions, including:
In addition, carnosine is said to boost the immune system, improve mood, improve memory, fight wrinkles and preserve eyesight.
As a 2018 review on carnosine reports, there is great potential for carnosine's application in health and disease. For example, carnosine has been found to have powerful antioxidant properties, allowing it to protect cells from free radical damage. It also appears to reduce inflammation, the cause of many types of chronic disease.
Because of these effects, it is thought that carnosine may help protect against a number of age-related conditions, such as Alzheimer's disease and cardiovascular disease. That said, very few clinical studies have tested the potential health benefits of taking carnosine supplements. Until such studies are conducted, it's hard to say how carnosine consumption may affect human health.
Here's a look at some of the most promising research on carnosine.
Animal and laboratory studies show that carnosine reduces the buildup of beta amyloid, the protein that forms the brain plaques associated with Alzheimer's disease.
In a study on mice published in 2013, oral supplementation with carnosine prevented cognitive decline because of its inhibition of amyloid-beta.
In 2016 research on healthy elderly people who supplemented with a carnosine-containing formula, scientists reported an improvement in the decrease in blood flow to the brain that occurs in Alzheimer's disease, as well as improved memory retention in participants. Similar results were shown in an animal model of Alzheimer's disease published in 2017.4
In light of this evidence, it has been hypothesized that carnosine controls the progression of Alzheimer's disease; however, clinical studies are still needed.
Carnosine may be particularly useful for people with diabetes as it may protect against damage caused by protein glycation. This process, which results from having too much sugar in the body, is a major contributor to diabetes-related complications, such as kidney and nerve damage.
Although evidence is still emerging, both animal and human studies have indicated the potential of carnosine supplementation (which is decreased in both animals and humans with type 2 diabetes) to delay the progression of diabetes and prevent such complications.
A pilot clinical study provided evidence of the ability of carnosine supplementation to protect against the development of diabetes in obese nondiabetic individuals. When overweight and obese adults were randomly assigned to ingest carnosine (two grams per day) or a placebo for 12 weeks , an increase in fasting insulin and insulin resistance was reported with the placebo, but not with carnosine. The group that received carnosine also had better responses to an oral glucose test (e.g., lower glucose and insulin).
These results, while promising, require further confirmation.
Several preliminary studies (cell cultures) suggest that carnosine may help fight cancer. For example, the presence of carnosine reduced growth on many of the major cancer cell types, including liver cells, colon cells, and ovarian cells. There is also evidence from studies correlating low levels of carnosine or high levels of carnosidase activity, the enzyme that breaks down carnosine, and a poor prognosis for cancer.
While interesting, it is important to remember that this research is in its infancy.
One of the few clinical studies involving carnosine is a small study published in the Journal of Child Neurology in 2002,9 In it, 31 children with autism spectrum disorders took either a carnosine supplement or a placebo every day for eight weeks. At the end of the treatment period, members of the carnosine group showed significantly greater improvements in some measures of functioning, including behavior and communication.
The study authors note that carnosine may benefit children with autism by improving nervous system function. Despite these promising results, more recent research on carnosine and autism has not been conducted.
