Home :: Carnitine

Carnitine - Benefits, Deficiency Symptoms And Food Sources

What is Carnitine?

Carnitine is not an amino acid in the strictest sense (it is actually a substance related to the B vitamins). However, because it has a chemical structure similar to that of amino acids, it is usually considered together with them.

Unlike true amino acids, carnitine is not used for protein synthesis or as a neurotransmitter. Its main function in the body is to help transport long-chain fatty acids, which are burned within the cells, mainly in the mitochondria, to provide energy. This is a major source of energy for the muscles. Carnitine thus increases the use of fat as an energy source. This prevents fatty buildup, especially in the heart, liver, and skeletal muscles. Carnitine may be useful in treating chronic fatigue syndrome (CFS), because a disturbance in the function of the mitochondria (the site of energy production within the cells) may be a factor in fatigue. Studies have shown decreased carnitine levels in many people with CFS.

Carnitine can be manufactured by the body if sufficient amounts of iron, vitamin B1 (thiamine), vitamin B6 (pyridoxine), and the amino acids lysine and methionine are available. The synthesis of carnitine also depends on the presence of adequate levels of vitamin C. Inadequate intake of any of these nutrients can result in a carnitine deficiency. Carnitine can also be obtained from food, primarily meats and other foods of animal origin.

Uses and Benefits of Carnitine

Carnitine reduces the health risks posed by poor fat metabolism associated with diabetes; inhibits alcohol-induced fatty liver; and lessens the risk of heart disorders. Studies have shown that damage to the heart from cardiac surgery can be reduced by treatment with carnitine. According to The American Journal of Cardiology, one study showed that proprionyl-L-carnitine, a carnitine derivative, helps to ease the severe pain of intermittent claudication, a condition in which a blocked artery in the thigh decreases the supply of blood and oxygen to leg muscles, causing pain, especially with physical activity. Carnitine has the ability to lower blood triglyceride levels, aid in weight loss, improve the motility of sperm, and improve muscle strength in people with neuromuscular disorders. It may be useful in treating Alzheimer's disease. Conversely, carnitine deficiency may be a contributor to certain types of muscular dystrophy, and it has been shown that these disorders lead to losses of carnitine in the urine. People with such conditions need greater than normal amounts of carnitine. Carnitine also enhances the effectiveness of the antioxidant vitamins E and C. It works with antioxidants to help slow the aging process by promoting the synthesis of carnitine acetyl-transferease, an enzyme in the mitochondria of brain cells that is vital for the production of cellular energy there.

Deficiency Symptoms of Carnitine

Many cases of carnitine deficiency have been identified as partly genetic in origin, resulting from an inherited defect in carnitine synthesis. Possible symptoms of deficiency include confusion, heart pain, muscle weakness, and obesity. Because of their generally greater muscle mass, men need more carnitine than women do. Vegetarians are more likely than non vegetarians to be deficient in carnitine because it is not found in vegetable protein. Moreover, neither methionine nor lysine, two of the key constituents from which the body makes carnitine, are obtainable from vegetable sources in sufficient amounts. To ensure adequate production of carnitine, vegetarians should take supplements or should eat grains, such as cornmeal, that have been fortified with lysine.

More information on carnitine

Supplemental carnitine is available in different forms, including D-carnitine, L-carnitine, and DL-carnitine. DL­carnitine is not recommended, as it may cause toxicity. Acetyl-L-carnitine (ALC), a carnitine derivative produced naturally in the body, is involved in carbohydrate and protein metabolism and in the transport of fats into the mitochondria. It increases levels of carnitine in tissues and even surpasses the metabolic potency of carnitine. ALC has be­come one of the most studied compounds for its anti-aging effects, particularly with regard to degeneration of the brain and nervous system. Several major studies have shown that daily supplementation with ALC significantly slows the progression of Alzheimer's disease, resulting in less deterioration in memory, attention and language, and spatial abilities. It also can be used to treat other cognitive disorders, as well as depression.

ALC provides numerous other benefits to many of the body's systems. It helps to limit damage caused by oxygen starvation, enhance the immune system, protect against oxidative stress, stimulate the antioxidant activity of certain enzymes, protect membranes, slow cerebral aging, pre­vent nerve disease associated with diabetes and sciatica, modulate hormonal changes caused by physical stress, and increase the performance-enhancing benefits of branched­chain amino acids.

Total brain levels of ALC (and carnitine) decline with age. In most of the studies of ALC done with humans, subjects took 500 to 2,500 milligrams daily, in divided doses. No toxic or serious side effects have been reported

Rich Food Sources of Carnitine

Carnitine is found in good amounts in red meat, while fish, chicken and milk are also high in carnitine, while vegetables and grains contain very little of this nutrient.

Caution

Supplements in excess of 3,000 mg (19 mmol) of carnitine per day may cause diarrhea or "fish odor" syndrome.