Carnitine – Food Sources, Deficiency and Its History

Carnitine is a substance derived from two amino acids, lysine and methionine, which plays a role in the transport of fatty acids. This process also requires the presence of vitamin C, iron, vitamin B6 and vitamin B3 (niacin) and several enzymes.

Carnitine plays an important role in the transport of long-chain fatty acids to the mitochondria (the components of the body’s cells). This process, in the mitochondria, enables the production of energy in the form of adenosine triphosphate (ATP). Carnitine is essential for the proper functioning of muscles, including the heart, muscle and increases the production of “fuel” for the cells when they have raised need of energy.

In the body, carnitine is mainly synthesized by the liver and the kidneys. As a synthetic supplement it’s synthesized in laboratory and sold as a dietary supplement in the form of L-carnitine and acetyl-L-carnitine (capsules, tablets, powder for concentrate, etc…). L-carnitine is water soluble while acetyl L-carnitine is liposoluble (fat soluble).

Dietary Sources Of Carnitine

The body synthesizes carnitine it needs from food. The best sources are meat, especially red, and to a lesser extent, dairy products, avocado and tempeh (a product made from fermented soybeans), spirulina algae, maca, quinoa. It is estimated that in our modern societies, dietary intake of carnitine is between 20 mg to 200 mg per day, much lower than the doses used in clinical studies. However, carnitine from food sources is absorbed much better (75%) than, when taken in supplement form (5% to 18%).

Carnitine Deficiency

Carnitine deficiency is relatively rare condition. It can be caused by the use of certain drugs (valproic acid, an anti-epileptic drug, and reverse transcriptase inhibitors such as AZT, for example) or by prolonged dialysis treatments.
It can also be caused by certain genetic diseases or metabolic dysfunction, that interferes with the normal synthesis of this substance in the body.

Premature infants, who are under intubation may suffer from a deficiency of carnitine. Such deficiency is characterized by muscle weakness, increased fatigability and cardiac arrhythmia.

History Of Carnitine

carnitine chemical formula

Carnitine was isolated from red meat in 1905 and synthesized in laboratory in 1927. Despite intensive studies during the 1930s, it was only in the second half of the twentieth century that we understand the role of this lipid transporter in the cells.

When in 1973 the first cases of carnitine deficiency have been reported in medical journals, experts wanted to define this substance as essential vitamin, because some people needed additional input of it in order to maintain good health. Others have objected, noting that normally the body synthesizes itself the carnitine it needs, which is not the case with vitamins. This debate continues till today. Generally today carnitine is considered as an amino acid.

It is mainly bodybuilders who use carnitine in the hope of reducing their body fat while increasing their performance and speed up recovery after exercise, but these effects have not yet been proven.

Researches On Carnitine

Some researches have been conducted over the improved efficiency and physical performance effects of carnitine. Carnitine improves the ability to provide physical exertion in people with heart diseases, respiratory failure, heart failure or carnitine deficiency. However, there is no evidence that this improvement also occurs in healthy individuals or athletes.

Preliminary studies have suggested that carnitine may improve physical performance, but subsequent studies have failed to confirm its effects. They indicate that supplementation does not increase the amount of carnitine in muscles, or production of energy during physical effort. But alternatively carnitine might reduce muscle stress after exercise.

Possible Contraindications

In the late 1990s, some reputable authors recommended to avoid taking carnitine in case of liver problems. However, according to recent tests, carnitine would rather be beneficial for some health problems and diseases.
It was also reported, that in epileptic patients, carnitine had increased seizure frequency.
Carnitine absorbed from food is safe, but there are no data on the safety of pharmacological doses of this supplement in children, pregnant women and nursing mothers.

Possible Adverse Effects Of Carnitine

Generally quite well tolerated by the body, carnitine may occasionally cause mild gastrointestinal disorders.

Taking more than 3 grams of carnitine per day can cause unpleasant fishy body odor. Increased agitation in people with Alzheimer’s disease have been reported during carnitine intake.
It was reported that carnitine could help increase the effects of acenocoumarol (Sintrom), an anticoagulant that have shorter duration of its action than warfarin. It is unknown whether carnitine increases the effects of the latter.

Consuming products containing carnitine is a fad that has spread in some sporting circles since the early ninety years in order to improve physical performance. Slimming products containing carnitine also appeared on the pretext that their action on the metabolism of fatty acids resulted in a better mobilization of fat, and so in weight loss.


3D structure of Carnitine

L-Carnitine And Sport

This effect is desired by both people, who want to lose weight and fitness enthusiasts, who wish to quickly transform their body fat in lean muscle mass. The usual recommended dose is 1000 mg to 2000 mg in the form of L-carnitine, acetyl-L-carnitine or L-carnitine-L-tartrate at breakfast, one serving before and after training.

You can use carnitine on tablets or capsules, but the liquid form of carnitine is considered better, because it is absorbed much faster by the body and thus you will see faster results.

The problem is that the main claimed and advertised effect attributed to carnitine does not exist. This effect received no scientific proof. Actually a research has clearly demonstrated that supplementation does not increase the amount of carnitine in the muscles, or the production of energy during exercise. The only advantage this research has been able to confirm is that carnitine could reduce muscle stress after exercise.

In fact, the sport diet does not differ much from the normal diet. If you exercise, you need a varied and rich diet, which must first comply with the general nutrition rules.
It’s recommended that you don’t favor one type of food over others.

Carnitine And Its Medical Use.

Carnitine is used experimentally as an adjunct in the treatment of angina, heart failure, cardiomyopathy and following myocardial infarction. Tests were also conducted with individuals suffering from Alzheimer’s disease and diabetic neuropathy.

It is taken orally or intravenously, and is used although experimental, in the treatment of certain diseases. Thus, it seems to have a positive effect on people with certain cardiovascular conditions (angina, coronary artery disease, peripheral arterial disease).

It alleviates the symptoms health conditions, improves the ability of patients to perform physical activities and, in some cases, allows a reduction of medications taken.

Carnitine also shown some efficacy in the treatment of peripheral neuropathy caused by diabetes or antiretroviral therapy.

But still, its efficacy in treating the cognitive decline associated with Alzheimer’s disease remains controversial.

Carnitine And Improved Physical Performance?

The results of completed clinical trials to date are inconclusive.
Current data indicate that a dose of 2 g of L-carnitine per day, divided into 1 to 3 doses, does not appear to present any danger to health.

In summary it is recommended that if you take the carnitine as supplement to be careful with its consumption if you are not familiar with its effects on your body. Use the carnitine after consultation with your doctor or dietitian and when you have gathered enough information about it. After all is like every other medicine and food supplement and thus you have to be very responsible and cautious what you put in your mouth and body.

Author: Jessy Donston

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