Since Fraenkel described its usefulness in 1947, carnitine has been targeted by researchers, nutritionists and physical trainers. The cult of the body, or the simple pursuit of health, have seen in this molecule (in L-carnitine, in particular) a solution to lose fat faster and more easily.
However, what do we know about her? Over time, scientific evidence does not make its utility so clear. Where does this supplement come from? Why has it been used for so long? And what is it really capable of? Let's talk about this flagship product in gyms.
Where does L-carnitine come from?
Levocarnitine, or L-carnitine, was discovered in 1905, in animal meat, although it was not until forty years after its fundamental role in life was understood. This quaternary amine is a "levo" stereoisomer of D-carnitine, the "dextrous" carnitine, which is not of biological utility to animals. Carnitine is synthesized from lysine and methionine with the help of iron and vitamins C, B3 and B6.
The function of L-carnitine is to mediate the transport of fatty acids into the mitochondria. This cellular organelle is responsible for cellular respiration and, therefore, the one in charge of producing energy. Without L-carnitine, the cell cannot use these fat molecules to produce ATP, which is the molecular unit of energy in the cell, which can be catastrophic.
Our body ensures production thanks to the kidney, liver and brain, although it can also be taken from products mostly of animal origin such as milk or meat
Our body ensures production thanks to the kidney, liver and brain, although it can also be taken from animal products such as milk or meat. Vegetables, however, do not contain carnitine or the amount they contain is very low, as with foods such as carrots, asparagus or rice. This is important in the case of special diets, although as has been proven, in principle, the L-carnitine we produce is sufficient for proper body functioning.
Its relationship with the sports and fitness world comes precisely from its role as a fat mobilizer. The idea is simple, and even logical: if this substance helps generate energy by consuming fatty acids, the more there is, the better. On the other hand, its ease of obtaining, as well as its relatively cheap cost, make the perfect recipe for this substance to have become one of the protagonists among dietary supplements.
L-carnitine: promises and hopes vs "reality"
Lack of L-carnitine can result in weight gain and fat accumulation (in addition to other more serious diseases). This, together with what we said, has caused many sports nutritionists and physical trainers to advise their consumption.
The most immature and simplistic idea in L-carnitine looks for a simple weight loss. The most serious preparers, however, point to this supplement as a substance that can help improve sports performance and fat burning. Researchers who have decided to go deeper into the topic have studied how L-carnitine could help cell and muscle metabolism.
Carnitine is used for the treatment of various diseases, but there is no evidence that it serves to lose weight
At the moment, we know that carnitine is used for the treatment of various diseases: it helps the proper functioning of the liver in people with non-alcoholic steatohepatitis, to treat low sperm motility or to reduce poisonings with valproic acid, a substance used in The treatment of epilepsy. However, nothing tells us that carnitine can help us in the management of fats at the sports level.
If what we are looking for is an improvement in the management of body fat or physical efficiency, it seems that we should give up. For the moment, Carnitine supplementation has not shown any type of ergogenic help (which improves the body's energy production) or performance in any sports discipline.
What does science say about L-carnitine?
Although some studies have shown very limited evidence about its impact on athletic performance, the bulk of research contradicts these results. At the moment, carnitine supplementation has not shown any type of ergogenic or performance assistance in any sports discipline.
Yes, there are certain results that suggest that this substance could help the recovery of the muscle before an intense exercise session. All this has its metabolic sense, strictly controlled: the excess of L-carnitine does not cause an increase in fat metabolism, but is excreted in the urine to maintain good cellular functioning.
Our body synthesizes the L-carnitine it needs at a specific time and the excess is eliminated
While we might think that if we need more L-carnitine (for a more intense exercise) our body could benefit from an additional supplement, the reality is that it synthesizes what it needs at a specific time and the excess is eliminated. Therefore, and although this supplement is constantly being advised, its effectiveness is seriously questioned. At the moment, apart from the treatment of pathologies, there are no reasons to supplement a diet with carnitine. And if we do, it will be better not to expect results, we will save a disappointment.