L-carnitine is a nutrient synthesized from the amino acids lysine and methionine in the liver and kidneys. Its primary function is to move fatty acids out of intracellular fluid and into the mitochondria for the purpose of converting lipids into fuel for energy. It is also available as a dietary supplement. L-carnitine is reputed to be helpful in treating a variety of conditions. However, check with your doctor first if you have a chronic condition or are taking medications.
Glucose Metabolism
One of the effects of L-carnitine on the body is to reduce insulin resistance in type 2 diabetics. In a review published in the Sept. 25, 2009 issue of Diabetes Metabolism Research and Reviews, Randall Mynatt of the Pennington Biomedical Research Center in Baton Rouge notes that the accumulation of lipid fats in intracellular fluid in tissue cells throughout the body directly contribute to insulin resistance. Of particular concern is too much fatty acyl CoA, as well as the accumulation of its byproducts. Since studies using animal models have shown that L-carnitine improves glucose utilization and promotes efficient energy production in cells, Mynatt asserts that more research is needed to investigate the potential of L-carnitine as a future therapy for type 2 diabetes.
Cardiovascular Effects
According to the University of Maryland Medical Center, several clinical studies demonstrate that L-carnitine improves symptoms and physical stamina in angina patients. A derivative of this nutrient, propionyl-L-carnitine, has shown similar effects in patients with heart failure in a few small studies. In addition, there is some evidence that supplementing with L-carnitine after experiencing a heart attack may reduce the risk of suffering another attack or developing heart failure. However, the center also points out that some of these studies were poorly designed, while others showed no benefit from L-carnitine supplementation at all. Therefore, the medical center cautions that this supplement should only be used under the supervision of a qualified health care practitioner, if there is a history of heart disease.
Male Fertility
A deficiency in L-carnitine is associated with low sperm counts in men. However, according to the University of Maryland Medical Center, L-carnitine supplementation may enhance sperm count and motility. In one placebo-controlled, double-blind, crossover trial involving 100 infertile men, researchers reported in the February 2003 issue of Fertility and Sterility that a significant improvement in semen quality and sperm motility was observed in the treatment group after L-carnitine supplementation.
Cognitive Effects
The University of Maryland Medical Center also says that some studies suggest that acetyl-L- carnitine may improve memory and even slow the progression of Alzheimer's disease. However, other studies show little or no benefit. Consult your physician about the use of this nutrient in treating Alzheimer's disease and other forms of dementia.
References
- Diabetes Metabolism Research and Reviews: Carnitine and Type 2 Diabetes; Mynatt R; Sept. 25, 2009
- University of Maryland Medical Center: Carnitine (L-carnitine)
- Fertility and Sterility: Use of Carnitine Therapy in Selected Cases of Male Factor Infertility: A Double-blind Crossover Trial; Lenzi A et al.; February 2003
Member Comments