L-carnitine: what is it and how does it act in our body?

This amino acid is found in many foods and has several health properties.

Nutritional supplements with L-carnitine have become popular in recent years to improve sports performance and to promote weight loss, in addition to other medical uses.

But what exactly is L-carnitine? How does it act in our body? And, most importantly, is it really effective in all its applications? In this article we will answer these questions.

What is L-carnitine?

L-carnitine is an amino acid produced by the kidneys and liver and stored in the brain. and is stored in the brain, heart, muscles and sperm. It is involved in the transformation of fats into energy and is attributed with antioxidant properties.

It is one of the two isomers or molecular structures of carnitine. While L-carnitine has positive effects on the body, the other isomer, D-carnitine, inhibits the activity of L-carnitine.

L-carnitine is found mainly in red meatespecially in lamb and beef. It can be found in moderate amounts in pork, cod, chicken breast and dairy products, and there is also a small concentration of this amino acid in some vegetables and cereals.

This compound is used as a supplement to treat various disorders of the body and to enhance metabolic activity.. However, not all of its applications have been supported by scientific research.

How does it act in the body?

L-carnitine serves to transport fatty acids across the mitochondrial membranes of cells. The enzyme carnitine palmitoyltransferase binds L-carnitine molecules to fatty acids.

This amino acid has antioxidant effectsIt eliminates free radicals, particles which, if they accumulate in excess, alter DNA and damage cells by oxidation, and may favor the appearance of cancer.

L-carnitine deficiencies can occur in the organism due to genetic alterations or malnutrition, as well as the exclusive consumption of plant foods.

The lack of L-carnitine can cause different alterations depending on the age, severity and organs involved. Some of the most characteristic symptoms of this alteration are the reduction in glucose levels (hypoglycemia), the appearance of heart muscle diseases (cardiomyopathy) and fatigue.

What is it used for?

The uses given to L-carnitine as a nutritional supplement are multiple, although not all of its alleged benefits have been demonstrated and there is still much research to be done. In this section we will detail the scientific evidence on the different applications of this substance.

In no case is it recommended to take L-carnitine supplements without a doctor's prescription, as it is a drug in the experimental phase in most of its applications.

1. Kidney diseases

The kidneys are involved in the production of L-carnitine, so that the Blood levels of this amino acid are affected when there is a kidney disease. are affected when kidney disease is present. It is in this area that external L-carnitine is most clearly effective.

L-carnitine supplements have been shown to be effective as an adjuvant for people undergoing hemodialysis, a form of therapy that replaces the function of the kidneys when they are not working properly. This not only reduces the symptoms of L-carnitine deficiency but may also prevent them.

Cardiovascular disorders

Scientific studies have found preliminary evidence in favor of the use of L-carnitine in diseases of the heart and circulatory system in general.

In particular, L-carnitine may increase the capacity for physical exertion in people diagnosed with angina pectoris or heart failure, as well as reduce the risk of mortality after heart attacks and in cases of cardiac inflammation (myocarditis).

On the other hand, it has been suggested that L-carnitine reduces pain and improves mobility in people with atherosclerosis, and that it prevents the appearance of this disorder by reducing cholesterol and triglyceride levels.

3. Weight loss

There is insufficient scientific evidence to affirm that L-carnitine is effective as a supplement to reduce weight, although this is one of its most famous applications.

Some studies claim that this compound reduces fat accumulation and increases muscle mass. In addition, the fatigue-reducing effects of L-carnitine may indirectly facilitate weight loss.

4. Male infertility

Male infertility has been linked with low levels of L-carnitine. According to research, supplementation of this amino acid is likely to increase sperm quantity and motility.

5. Diabetes

L-carnitine may help regulate blood glucose levels in people with diabetes when taken as a of people with diabetes if taken as an adjunct to specific medication to treat this disease.

In the same vein, it may be effective in reducing the symptoms of diabetic neuropathy, which occurs when elevated glucose levels damage the nerves in the extremities, causing pain and numbness.

6. Hyperthyroidism

L-carnitine appears to reduce the symptoms of hyperthyroidisma disorder characterized by excessive secretion of thyroid hormones. Studies are promising but inconclusive at this time.

Typical symptoms of hyperthyroidism include tachycardia, anxiety, insomnia, physical weakness and tremors.

7. Erectile dysfunction

Although more studies are needed to confirm this, it has been suggested that L-carnitine may increase the effectiveness of Viagra. may increase the effectiveness of Viagra in cases of impotence, especially in men who do not respond adequately to this medication and who have undergone prostate surgery.

8. Fatigue

There is preliminary scientific evidence for the usefulness of L-carnitine for reducing age-related fatigue, cancer, celiac diseaseThere is preliminary scientific evidence for the usefulness of L-carnitine in reducing age-related fatigue, cancer, celiac disease, hepatitis, multiple sclerosis and chronic fatigue syndrome, as well as fatigue in general.

9. Sports performance

Intense physical exercise has been linked to a decrease in L-carnitine levels, so many athletes use these supplements to improve their performance. many athletes use these supplements to improve their performance.. However, although some studies support this hypothesis, it cannot be affirmed that L-carnitine is useful to improve sports performance.

Bibliographical references:

• Steiber A., Kerner J., Hoppel C.L. (2004). Carnitine: a nutritional, biosynthetic, and functional perspective. Molecular Aspects of Medicine. 25 (5–6): 455 - 473.
• Vaz F.M., Wanders R.J.A. (2002). Carnitine biosynthesis in mammals. Biochem. J. 361: 417 - 429.
• Wall B.T., Stephens F.B., Constantin-Teodosiu D., Marimuthu K., Macdonald I.A., Greenhaff P.L. (2011). Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. PubMed.gov.