Earlier this week, the amino acid L-carnitine was deemed safe, and thereafter released by Health Canada for non-restricted supplemental use. The availability of this effective nutrient will be an excellent addition to natural antioxidant options. This article will discuss L-carnosine, featured yesterday on the Dr. Oz show, and the lesser known counter-part of L-carnitine.
While L-carnitine garners attention for its benefits in addressing weight loss, diabetic complications, mitochondria function and cardiovascular health, L-carnosine is quietly emerging as the new antioxidant powerhouse. There is exciting new research being conducted using L-carnosine in areas such as brain health, stroke recovery, anti-aging, cataract treatment, immune stimulation, athletic performance and many others. Study results are still preliminary, and little is known about how exactly carnosine works in the body to exert a positive effect in so many diseases. This article will provide a review of the latest research regarding carnosine for cataracts and immune function.
Believe it or not, there is new research that may support the benefit of chicken soup in fighting off viral infections and boosting our immune system (Babizhayev 2012). A recent study found that carnosine, a potent antioxidant found in chicken (and chicken soup), has a key role is disrupting viral replication and spread inside our cells. Carnosine is a key antioxidant with a primary role of neutralizing damaging free radicals inside our cells. By comparison, vitamin C is another potent antioxidant, although its role is outside the cell. The influenza virus causes its damage and infection by taking over our own human cellular machinery to make more copies of itself. It will actually infect and hijack healthy human cells as a mechanism to spread its infection. The study found that carnosine blocks this “hijacking” process by quenching free radials produced by the virus. This suggests that a diet high in carnosine could help prevent and possibly even stop the flu.
One of the most exciting applications of carnosine has been in ocular health and the potential treatment of cataracts. Much of the research on this application has been conducted by Russian scientists leading to the approval of carnosine as treatment for cataracts in Russia. L-carnosine reduces the products of lipid peroxidation and protein cross-linking within the ocular lens, which are responsible for the formation of less opacity (cataracts). Furthermore, there is some evidence that carnosine has the ability to disassemble clumped proteins that make up existing cataracts. There have been a number of well-structured trials that have found that N-acetyl-L-carnosine eye drops have led to a number of ocular benefits. Patients in early stage cataracts found they had better lens clarity and no progression of their cataracts. One small study foundthat90% of patients in the treated group had improved visual acuity and 89% showed improved glare sensitivity (Babizhayev et al 2001). The most recent study featured 75 patients with cataracts and 72 without. 1.0% N-acetyl-L-carnosine (NAC) drops were used daily for 9 months. In both groups, visual acuity and reduction in glare sensitivity were significantly improved at 9 months (Babizhayev et al 2009). Based on these results, it could be suggested that NAC eye drops could benefit a number of other ocular disorders, but direct research is very limited.
It is important to note that instead of using carnosine itself, more recent trials have used N-acetyl-L-carnosine, a metabolite of carnosine. The body slowly converts N-acetyl-L-carnosine back into free carnosine. This allows for slower, more thorough delivery of free carnosine into the eye's tissues, and access to areas of the eye where carnosine itself is broken down quickly by the carnosinase enzyme.
Other Health Benefits
Carnosine has a number of other potential uses due to its broad spectrum or “pluripotent” effect. There is evidence that it can improve wounds, especially poorly healing diabetic wounds. It has also been shown to improve leaky gut syndrome and promote the healing of the gastric mucosa (Mahmood et al 2007). Carnosine has been implicated in exercise performance because the supplementation of beta alanine increases carnosine levels. Studies have found that beta alanine supplementation can improve muscle fatigue by decreasing lactic acid levels since carnosine is an intracellular buffer (Hobson et al 2012). Carnosine has also been studied for the prevention of Alzheimer’s disease, diabetes, kidney disease, and stroke recovery (Hipkiss 2009).
It is also important to note that oral bioavailability is an issue because the presence of the enzyme carnosine in human blood, which cleaves the dipeptide into its component amino acids ?-alanine and histidine. There is still some benefit from the supplementation of carnosine, but research is being conducted on how to improve bioavailability through different forms that are resistant to degradation (Hipkiss 2009).
The various and extensive mechanisms of carnosine make it a promising anti-aging agent as well as a potentially powerful therapeutic for various pathological processes. A summary of the physiological effects of carnosine includes its role as an antioxidant, antiglycating agent, metal chelating agent, aldehyde scavenger, carbonyl scavenger, and stimulator of nitric oxide synthase (Hipkiss 2009).
The future of carnosine as a nutrient is very bright, and more research is needed to fully understand how it works in the body and how to harness its health potential.
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Babizhayev MA, Deyev AI. Management of the virulent influenza virus infection by oral formulation of nonhydrolized carnosine and isopeptide of carnosine attenuating proinflammatory cytokine-induced nitric oxide production. Am J Ther. 2012 Jan;19(1):e25-47
Hipkiss AR. Carnosine, diabetes and Alzheimer's disease. Expert Rev Neurother. 2009 May;9(5):583-5.
Babizhayev MA, Deyev AI, Yermakova VN, et al. Efficacy of N-acetylcarnosine in the treatment of cataracts. Drugs R D. 2002;3(2):87-103
Babizhayev MA, Burke L, Micans P, Richer SP. N-Acetylcarnosine sustained drug delivery eye drops to control the signs of ageless vision: glare sensitivity, cataract amelioration and quality of vision currently available treatment for the challenging 50,000-patient population. Clin Interv Aging. 2009;4:31-50.
Kaczor, Tina. L-Carnosine’s Effects on Cataract Development. Natural Medicine Journal 2(4), April 2010
Mahmood A, FitzGerald AJ, Marchbank T, Ntatsaki E, Murray D, Ghosh S, Playford RJ.
Zinc carnosine, a health food supplement that stabilises small bowel integrity and stimulates gut repair processes. Gut. 2007 Feb;56(2):168-75.
Hobson RM, Saunders B, Ball G, Harris RC, Sale C. Effects of ?-alanine supplementation on exercise performance: a meta-analysis. Amino Acids. 2012 Jul;43(1):25-37.