Carnosine as a therapeutic supplement
Carnosine, or L-carnosine, is a naturally occurring peptide in the human body, composed of the amino acids alanine and histidine. It is primarily found in the brain, nervous system, lenses of the eyes, and skeletal muscle. While the body synthesizes carnosine from dietary proteins, it is promoted as a therapeutic supplement for various health conditions, particularly as an anti-aging nutrient. Additional proposed uses include potential benefits for Alzheimer's disease, autism, cataracts, sports performance, neurological disorders, diabetes management, wound healing, and cardiovascular health.
Although carnosine exhibits antioxidant properties, which may help combat chronic diseases linked to free radicals, scientific evidence supporting its effectiveness varies. Studies suggest it might improve symptoms in conditions like Parkinson's disease and enhance insulin sensitivity in diabetes patients. However, the quality of the existing research is mixed, and the recommended dosages remain a topic of debate. Importantly, carnosine has not been associated with significant side effects, but safe usage guidelines for specific populations, such as children and pregnant women, are not well established. Further research is necessary to validate its therapeutic claims and understand its full range of effects.
Carnosine as a therapeutic supplement
DEFINITION: Natural substance of the human body used as a supplement to treat specific health conditions.
PRINCIPAL PROPOSED USE: Anti-aging nutrient
OTHER PROPOSED USES: Alzheimer’s disease and related conditions, autism, cataracts, sports and fitness support: enhancing performance, neurological disorders, diabetes management, wound healing, cardiovascular health
Overview
Carnosine (L-carnosine), not to be confused with L-carnitine, is a substance manufactured in the human body, made by combining the amino acids alanine and histidine. The highest levels of carnosine are found in the brain and nervous system, the lens of the eye, and skeletal muscle tissue. Its exact function in the body is not known.
Requirements and Sources
The body manufactures carnosine from common dietary proteins, so there is no daily requirement for this substance.
Therapeutic Dosages
Among advocates of carnosine, there is a controversy regarding whether the proper dose is 50 to 150 milligrams (mg) per day or nearer to 1,000 mg daily. However, until carnosine has been shown to have confirmed medical benefits through rigorous scientific study, this argument cannot be settled.
Scientific Evidence
Like numerous other substances, carnosine has antioxidant properties, neutralizing dangerous, naturally occurring substances called free radicals. Free radicals are thought to play a role in many chronic illnesses, such as cardiovascular disease. On this basis, many antioxidant substances have been studied for potential health-promoting properties. Some Internet sites claim that carnosine acts as an antioxidant in a unique way, fighting the “second wave” effects that follow attacks by free radicals. However, there is no meaningful evidence to support this theory or the hypothesis that such an effect, if it truly exists, would provide any health benefits.
Antiaging. Carnosine is widely marketed as an anti-aging nutrient. Numerous studies hint that it might help slow various aspects of aging. However, the quality of these studies is too low to provide reliable evidence for benefit.
Brain disorders. Carnosine has been studied in Parkinson’s disease. In a small, controlled trial, adding carnosine to the diet of people being treated for Parkinson’s disease improved their symptoms. There is also weak evidence that carnosine may be helpful for Alzheimer’s disease and other forms of dementia. Carnosine can be found in the olfactory tissue, which is responsible for the sense of smell. Because of this, some researchers have suggested that carnosine should be administered through the nose (rather than by mouth), especially considering that people with Alzheimer’s disease often have problems with their ability to detect odors. This use for carnosine and this method of administering it are in need of further study.
Sports performance. It has been suggested that taking supplements of the amino acid alanine can raise carnosine levels in muscle and, in turn, enhance sports performance. In one small trial, twenty-six men were randomized to receive 6,400 mg daily of carnosine or a placebo over ten weeks. The men then underwent an exercise training program, and their physical fitness was assessed after ten weeks. Researchers, though, did not find any significant differences between the two groups. Despite this evidence, carnosine remains a popular supplement for athletes.
Other conditions. Other weak evidence hints that oral carnosine might be helpful for cataracts, wound healing, conditions of the digestive tract, and various forms of heart disease, such as atherosclerosis (hardening of the arteries). For example, one study found that carnosine may interfere with the development of low-density lipoproteins (LDL, or bad cholesterol). Research through double-blind, placebo-controlled studies continues to determine carnosine's health benefits. A 2018 study examining carnosine's effects on diabetes patients found it had a beneficial impact on managing the chronic condition. A 2017 study also found supplementation with carnosine helped improve insulin sensitivity and secretion.
Safety Issues
The use of carnosine has not been associated with any significant side effects. However, the body deploys a range of enzymes, called carnosinases, to break down carnosine. There may be a reason for the presence of these enzymes, and overcoming them by providing large amounts of supplemental carnosine could conceivably cause harm in some as-yet unrecognized way. Maximum safe doses in young children, pregnant or nursing women, and people with severe liver or kidney disease have not been established.
Bibliography
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