In the world of nutrition, bodybuilding and fitness, amino acids have a special place. They enhance metabolic functions, build muscle, and help the mechanism that burns fat. Many of these amino acids are marketed in products at specialty stores, but sometimes it's hard to tell between various products with similar names, like L-carnitine and Acetyl L-carnitine.
What is Carnitine (L-carnitine)?
According to the National Institutes of Health Office of Dietary Supplements, carnitine, also known as L-carnitine, plays a major role in energy production. The amino acid “transports long-chain fatty acids to [cellular] mitochondria so they can be oxidized (“burned”) to produce energy.” L-carnitine also transports toxins out of the mitochondria. The amino acid is found in muscle tissue, liver, heart and brain.
The liver and kidneys produce this amino acid. Excess is excreted in the urine. Healthy people who have a well-rounded diet rarely need supplements. Those suffering kidney and liver problems need to consult their doctors regarding the use of L-carnitine. Those on certain medications for seizures and thyroid conditions should also consult a doctor on the use of L-carnitine.
Uses for L-carnitine
Outside of L-carnitine's functions in muscle and organ, the amino acid has been studied for possible therapeutic effects on male infertility. L-carnitine has been shown to enhance the effect of Sildenafil (Viagra), thus aiding in erectile dysfunction. Chronic Fatigue Syndrome and hyperthyroidism are also conditions for which L-carnitine may have a beneficial effect. L-Carnitine is also being looked at for effects on heart disease and blood circulation, fatigue due to cancer chemotherapy and benefits for those who suffer from kidney ailments and HIV/AIDS.
Where do we Get L-carnitine?
We synthesize carnitine in our bodies or we can get it from from red meats, milk and some grains. We can also get the amino acid from supplements.
What is Acetyl L-carnitine?
Acetyl L-carnitine is the acetylated form of L-carnitine. This form of L-carnitine is more easily accessed by the body, as it absorbs into the small intestine and passes through the blood-brain barrier more efficiently. This form of carnitine is often used to treat carnitine deficiencies.
Acetyl L-carnitine has been studied extensively for properties that may benefit those who suffer Alzheimer's disease. The amino acid has also been studied for potential effects on Peyronie's disease and diabetic neuropathy.
L-carnitine, Acetyl L-carnitine and Fitness
Both L-carnitine and Acetyl L-carnitine have been marketed for their benefits to bodybuilding, physical performance and weight loss. The Amazon.com product description for IDS Acetyl L- Carnitine capsules claims that the product “Enhances Immune system function. Enhances hormone levels. Enhances mood.”
However, according to the NIH, “twenty years of research finds no consistent evidence that carnitine supplements can improve exercise or physical performance in healthy subjects...”