Life Extension Magazine®
Carnosine is showing promise in preventing the initial stages of atherosclerosis, an occlusive arterial disorder that worsens as people age.
Despite reduced prevalence of coronary artery blockage and ischemic stroke in middle aged adults, these vascular disorders remain leading causes of disability and death.
When atherosclerosis-prone mice were supplemented with carnosine, there was reduced formation of atherosclerotic plaque in their aortic valves and reduced accumulation of aldehyde complexes.1
Aortic stenosis is especially prevalent in people over age 70 and is a causative factor in chronic heart failure.
Studies show that carnosine (a combination of two amino acids) can help protect aging arteries against the harmful effects of excess body fat.
Red meat is the primary source of carnosine in the diet. Yet even meat eaters obtain only temporary carnosine blood levels. As people switch to healthier plant-based diets, they may be getting no protective carnosine.
Two Forms of Body Fat: White Fat and Brown Fat
All body fat isn’t the same.
White fat is what we usually associate with overweight people. It predominates in adults, stores calories, tends to accumulate where we least want it (especially around the belly), and results in damaging inflammation.
But brown fat is a completely different kind of fat. It is abundant in infants and hibernating animals. It burns calories and releases that energy as heat.2-4
That heat benefits babies, and it’s good for bears in cold environments. In adult humans, that heat represents a desirable “burning” of energy that may reduce the amount of overall fat in the body.3-5
Promoting conversion of white to brown fat may help reduce obesity and the inflammation and other risks that come with it.2,4
Carnosine Reduces Weight Gain
In a study published in 2018, scientists studied carnosine in the muscles and brain of animals to determine its fat-browning properties.2
In this study, rats were fed regular and high-fat diets. For six weeks the rats were either supplemented with carnosine, or not.
Researchers observed the impact of carnosine on the animals’ body weight and markers of oxidative stress.2 This is a way to study some of the factors that contribute to arterial damage that sets the stage for future heart attacks and ischemic strokes.
What they found was that either carnosine alone, or exercise, significantly reduced body weight gain, ameliorated obesity-induced lipid abnormalities, and blunted the rise of chemically-stressed fat molecules and their inflammatory byproducts.2
Underlying these changes, researchers saw an increase in the calories burned and a reduction of the overall fat load.
Not surprisingly, the greatest benefit was seen in the rats that were supplemented with carnosine and subjected to daily exercise, suggesting a synergistic effect.
The bottom line is that carnosine, alone or in combination with exercise, may reduce body weight gain and white fat stores by increasing the amount of brown fat in the body. That, in turn, may drive down the risk for cardiovascular disease and other complications of obesity.
Unique Properties of Carnosine
Carnosine has been shown to have multiple properties that may reduce risk factors for cardiovascular disease as follows:
- Carnosine increases the conversion of dangerous white fat into beneficial, energy-burning brown fat. This could reduce overall body fat content.
- Carnosine may also help cut down levels of circulating lipids that can be damaged by oxidative stress—direct contributors to plaque in the arteries. (Excess body fat, oxidative stress and unstable LDL cholesterol are risk factors for the chronic degenerative diseases that we associate with the aging process.)
- Carnosine helps neutralize oxidized lipids and their aldehyde byproducts by binding to them and rendering them harmless. Carnosine has been shown in animals to “pull” the aldehydes out of the body.
These findings represent advances in our understanding of vascular and muscle damage that occurs with aging.
Protecting Against Dangerous Aldehydes
Carnosine is being studied by researchers looking for ways to protect against the damaging effects of oxidized fats in the body and lipoproteins (like LDL) in the blood.6,7
Aldehydes are toxic chemicals created when oxidative compounds damage lipids and protein structures in our body. These aldehydes inflict damage on arteries and structures in the heart (including muscle, valves and coronary arteries).8,9
Carnosine seems custom-made to protect against this dangerous onslaught. It can neutralize and protect against oxidized lipids and aldehydes. One group of researchers found that carnosine inhibited formation of two highly damaging aldehydes, 4-HNE (4-hydroxynonenal) and MDA (malondialdehyde).1,9,10
In animals, the study found that supplementing atherosclerosis-prone mice with carnosine significantly reduced formation of atherosclerotic plaque in their aortic valves and reduced accumulation of dangerous aldehyde complexes. What’s more, carnosine was found to tightly bind to the aldehydes and carry them out of the body in the mice’s urine.1
Another study confirmed carnosine’s ability to neutralize aldehydes. Researchers pretreated heart muscle cells with carnosine and then exposed them to aldehydes like 4-HNE. Cells treated with carnosine lived longer than the cells that didn’t receive carnosine treatment.11
Challenge in Achieving Sustained Carnosine Blood Levels
The primary dietary source of carnosine is red meat, which many health-conscious people are seeking to reduce or eliminate from their diets.
Excess consumption of red meat increases the risk of heart disease, certain cancers, and other disorders. As a result, health-conscious people are eating more fruit, vegetables, and fish, and are staying away from beef.
A fascinating study of 18 people sought to determine carnosine concentrations in blood plasma after eating beef.12
Each 7.1-ounce serving of ground beef in this study contained 248 mg of carnosine.
In the study’s first phase, meat foods were removed from the diet for 48 hours. When fasting blood levels were measured, no carnosine was present.
After the subjects ate 7.1 ounces of ground beef, carnosine was detected in the blood within 15 minutes and continued to increase for several hours. After 5.5 hours, however, there was again no carnosine in the blood. This study showed that 248 mg of dietary carnosine does not provide the body with all-day benefits.
The reason carnosine disappears so quickly from the blood is the presence of an enzyme (carnosinase) that degrades carnosine in the body. This study on carnosine blood levels after ground beef ingestion confirms earlier recommendations that people supplement with higher doses of carnosine.13 Most people today supplement with 500 mg of carnosine once or twice daily
Summary
Carnosine shows promise in combatting the damage that can cause arterial blockage, aortic valve stenosis, and unwanted weight gain.
Dietary sources of carnosine do not provide sustainable blood levels. As people switch to healthier plant-based diets, they may have zero levels of carnosine in their blood.
Carnosine was at one time an expensive dietary supplement. Improvements made nearly 20 years ago enable most people to obtain potent carnosine doses at affordable costs.
If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.
References
- Barski OA, Xie Z, Baba SP, et al. Dietary carnosine prevents early atherosclerotic lesion formation in apolipoprotein E-null mice. Arterioscler Thromb Vasc Biol. 2013 Jun;33(6):1162-70.
- Schaalan MF, Ramadan BK, Abd Elwahab AH. Synergistic effect of carnosine on browning of adipose tissue in exercised obese rats; a focus on circulating irisin levels. J Cell Physiol. 2018 Jun;233(6):5044-57.
- Enerback S. Brown adipose tissue in humans. Int J Obes (Lond). 2010 Oct;34 Suppl 1:S43-6.
- Devlin MJ. The “Skinny” on brown fat, obesity, and bone. Am J Phys Anthropol. 2015 Feb;156 Suppl 59:98-115.
- Kim SH, Plutzky J. Brown Fat and Browning for the Treatment of Obesity and Related Metabolic Disorders. Diabetes Metab J. 2016 Feb;40(1):12-21.
- Xie Z, Baba SP, Sweeney BR, et al. Detoxification of aldehydes by histidine-containing dipeptides: from chemistry to clinical implications. Chem Biol Interact. 2013 Feb 25;202(1-3):288-97.
- Moss JWE, Williams JO, Ramji DP. Nutraceuticals as therapeutic agents for atherosclerosis. Biochim Biophys Acta Mol Basis Dis. 2018 May;1864(5 Pt A):1562-72.
- Nelson MM, Baba SP, Anderson EJ. Biogenic Aldehydes as Therapeutic Targets for Cardiovascular Disease. Curr Opin Pharmacol. 2017 Apr;33:56-63.
- Schaur RJ, Siems W, Bresgen N, et al. 4-Hydroxy-nonenal-A Bioactive Lipid Peroxidation Product. Biomolecules. 2015 Sep 30;5(4):2247-337.
- Ayala A, Munoz MF, Arguelles S. Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal. Oxid Med Cell Longev. 2014;2014:360438.
- Zhao J, Posa DK, Kumar V, et al. Carnosine protects cardiac myocytes against lipid peroxidation products. Amino Acids. 2019 Jan;51(1):123-38.
- Park YJ, Volpe SL, Decker EA. Quantitation of carnosine in humans plasma after dietary consumption of beef. J Agric Food Chem. 2005 Jun 15;53(12):4736-9.
- Available at: https://www.lifeextension.com/magazine/2006/1/awsi/Page-01. Accessed April 24, 2019.