Blood, sweat and tears: in top-class sports, athletes go to the absolute limit to achieve peak performance. In addition to the dream of being the best in the world, there is also a lot of money at stake, especially in soccer. Which is why some do not shy away from taking doping substances. But the fear of getting caught also keeps many from doing so!
"Doping can also be done legally"
is now claimed by some sports physicians, but is there really anything to it?
One of the body's own substances is mentioned again and again: L-carnitine. This was first taken in 1980 during the Olympics by Italian endurance athletes, who won a surprising number of medals that year. In 1982, L-carnitine was used at the World Cup in Spain by the Italian national team, which emerged as world champions in the sports competition and also had the lowest injury rate of any team in the tournament. When this information became known, carnitine was used by many top athletes in the 1980s and 1990s, but they did not take this secret tip to the public.
Since L-Carnitine is not listed as a doping agent, it remains a popular means of gaining a legal advantage in sports. Until the 1980s, carnitine was hardly affordable for normal people; nowadays, optimized manufacturing processes can ensure high and consistent quality at a reasonable price. That is why it is now affordable even for athletes who see their activity as more than a mere hobby and have neither a huge budget nor a team of specialists behind them .
What is L-Carnitine?
The natural dipeptide carnitine belongs to the vitaminoids (vitamin-like compounds that the body can produce itself) and is formed from the amino acids methionine and lysine in the liver and kidneys. Most animals, plants and microorganisms also carry the substance.
Carnitine was discovered in beef in 1905 and was given the name vitamin BT in 1952, but this name is no longer in use today. In addition to its use in competitive sports, it is used in complementary medicine for some diseases, such as kidney disease or certain types of cancer. Carnitine serves as a transport molecule, is indispensable for our fat burning and is also involved in the metabolism of carbohydrates and proteins. The substance is also essential for the removal of metabolic waste products from the cells. In addition, it influences the regulation of inflammation and protection against free radicals.
Carnitine is therefore a true all-rounder. Although the substance is also found to a small extent in plants, the name already reveals what it is most contained in. Carnitine was derived from carnis, the Latin word for meat. Especially red meat of sheep and lamb and also mother's milk have an increased carnitine content. Therefore the covering of the Carnitinbedarf by the food with Veganern lies on the average only with approx. 3% to 10%. The rest has to be synthesized by the body itself by consuming the co-factors vitamin C, vitamin B3, vitamin B6, vitamin B12 and iron . In total, our body contains between 20 and 25 grams of carnitine. In tissues with a high fatty acid metabolism, the proportion is particularly high. In our heart and skeletal muscles, 98% of the reserves are stored. In exceptional situations with increased loss of carnitine, the demand can even exceed the biosynthetic capacity. For example, people with certain diseases, such as dialysis patients receive supplemental carnitine as part of their treatment because their losses of it exceed new formation. Diabetes or liver cirrhosis can also promote carnitine deficiency .
The multiple tasks of carnitine
Carnitine and the burning of fat
Carnitine is an indispensable component for fat burning in the body, because it is involved in the so-called β-oxidation (oxidation of fatty acids). In this process, carnitine serves as a bio-carrier by enabling the long-chain fatty acids to enter the mitochondria (power plants of our cells) in order to be converted into energy in the form of ATP. ATP is the universal energy carrier of our cells, providing our body with 90-95% of the energy it needs .
Researchers are still trying to clearly clarify whether and in whom additionally supplied carnitine really helps with fat burning. A study with overweight subjects provided initial indications in this regard. In this study, a significant increase in fat burning was achieved, while protein synthesis and breakdown rates remained unchanged . No wonder that carnitine is often brought into the conversation when the goal is the loss of fat without the loss of muscle mass.
Carnitine and the carbohydrate metabolism
Even though carnitine is primarily known for its effect on fat metabolism, it also has a non-negligible influence on our carbohydrate metabolism.
In short, carnitine is necessary for enzymes needed for sugar and protein metabolism to be available in sufficient quantities in the body. In addition, the substance stimulates the burning of sugar by lowering an enzyme that reduces glucose burning. Waste products that interfere with sugar metabolism are also eliminated by the involvement of carnitine.
For those who are also interested in biochemistry:
Among other things, carnitine also regulates the availability of free coenzyme A. This is involved not only in fat metabolism, but also in sugar and protein metabolism. It acts as a buffer substance, as the carnitine-dependent enzyme carnitine transferase lowers acetyl-CoA levels by regenerating it back to coenzyme A. This process is also important for carbohydrate metabolism. This process is also important for carbohydrate metabolism because acetyl-CoA inhibits the entry of pyruvate into the citrate cycle. Pyruvate is an integral part of glycolysis (breakdown of sugar for energy). Thus, energy production from sugar is impaired when there is little coenzyme A and too much acetyl-CoA. This is why an adequate supply of L-carnitine is also necessary for optimal carbohydrate metabolism [6,7].
The task of L-carnitine for detoxification
Many products that promise a detoxifying effect often pursue a good approach, but do not provide clear proof of the extent to which they really contribute to detoxification. It has long been biochemically proven that a sufficient carnitine level is necessary to get rid of certain substances during mitochondrial detoxification. As an indispensable carrier molecule, it not only transports long-chain fatty acids into the mitochondria, it also carries unwanted metabolic products out of the cells. If the supply is insufficient, the waste products can accumulate in the mitochondria. Among other things, this can impair the action of insulin (uptake of glucose/sugar by the blood into the cells) and the activity of important enzymes involved in cellular energy metabolism (citrate cycle). Carnitine is also involved in the detoxification of certain drugs such as valproic acid .
So can supplemental carnitine really make sense? To answer this question, let's take a look at some promising studies.
Study proves: carnitine for our muscles
A crossover study investigated the influence of L-carnitine L-tartrate (L-carnitine bound to tartaric acid) on the destruction of muscle tissue after heavy squat exercise. Here, 10 resistance-trained men ingested a placebo or supplement (2 g L-carnitine/day) for three weeks. All men performed a set squat protocol of 5 sets and 15-20 repetitions. The extent of muscle injury, as determined by MRI scans, in the carnitine group was only 41 to 45% of what was seen in the placebo group. These data suggest that carnitine supplementation may be effective in supporting muscle recovery after high effort, high repetition exercises .
A placebo-controlled double-blind study provides a possible explanation of the effects to which the results of the previous study are attributable. Here, the effect of supplementation with carnitine tartrate on markers of performance and recovery from physical exertion was investigated in middle-aged men and women. The study involved 9 active and healthy men (between 40 and 50 years of age) and women (between 46 and 56 years of age) each. Half of the subjects received 2 grams of L-carnitine, while the rest of the test group received a placebo. After 3-weeks of ingestion, each participant performed acute resistance exercise with 4 sets of 15 repetitions of squats/leg presses (at 50% of maximum for one repetition) and continued supplementation during the recovery period. Blood samples were collected before, during, and after the resistance training sessions and also during the four recovery days.
Result: The carnitine group demonstrated significant reductions in biochemical markers, for exercise-induced tissue damage, free radical formation (malondialdehyde), muscle tissue breakdown (myoglobin, creatine kinase), and purine metabolism (i.e., hypoxanthine, xanthine oxidase), and muscle soreness compared to the placebo group. These results suggest that carnitine supplementation may reduce post-exercise tissue damage and optimize muscle tissue repair and remodeling processes .
Carnitine for the maintenance of body weight during illness
Loss of skeletal muscle mass, also known as muscle wasting or atrophy, is a common symptom of various chronic diseases such as cancer and infectious diseases, the negative effects of which greatly reduce our quality of life. L-carnitine supplementation has been shown to induce anti-catabolic (i.e. preventing muscle loss) effects in patients with chronic diseases.
A review summarizing results of clinical trials and animal studies with L-carnitine supplementation shows that L-carnitine supplementation under pathological conditions, i.e. in the disease state, leads to an improved nitrogen balance (marker for protein metabolism). The increase of protein synthesis or the reduction of protein degradation as well as the inhibition of apoptosis (programmed cell death) and/or an abolition of inflammatory processes are possible explanations . However, more research is needed to clarify what is now the decisive factor for the mechanism of action.
There is already a promising randomized and placebo-controlled double-blind study of 152 patients with advanced pancreatic cancer. It investigated whether L-carnitine can help with cachexia (loss of more than 10% of body weight). For 12 weeks, one group was given 4 grams of L-carnitine (4 g) orally, while the other group received a placebo. At baseline, patients reported a mean weight loss of 12 kg. During treatment, the body mass index of the L-carnitine group increased by an average of 3.4%, while it decreased by an average of approximately 1.5% in the placebo group. In addition, nutritional status (body cell mass, body fat) and quality of life parameters improved under L-carnitine. These data suggest that patients with pancreatic cancer may derive clinically relevant benefits from oral supplementation of L-carnitine .
Who should take carnitine to prevent deficiency?
A healthy person with a normal diet who does not need to achieve peak physical performance usually does not need to worry about becoming carnitine deficient. However, there is evidence that supplementation, even in healthy individuals, can help provide a muscle recovery benefit during vigorous exercise.
When metabolism enters a catabolic (degrading) state due to chronic disease, increased excretion of poorly utilizable acidic metabolic intermediates and increased muscle breakdown can deplete the body's carnitine stores .
It has been shown that the level of carnitine in tissues decreases dramatically with age, similar to Q10, glutathione and other endogenous substances . Presumably, as with glutathione , the decline in endogenous synthesis is also quite individual. This is why all people benefit to different extents from an external supply of these endogenous substances.
In a healthy person, L-carnitine can be transported in the kidneys highly efficiently through the renal tubules. The reabsorption is usually over 98%. Through this mechanism, the body's own L-carnitine stores remain well filled. However, if reabsorption is limited by renal disease or impaired by substances such as certain drugs, the body's own stores may be rapidly exhausted by increased urinary excretion . For these reasons, it is common to give additional L-carnitine to patients on dialysis due to renal failure, as the uptake through self-synthesis and diet is insufficient to compensate for the losses.
There are other factors that can inhibit the reabsorption of carnitine through the renal tubules and increase its excretion. These include conditions such as diabetes mellitus, metabolic stress following major injuries and surgery, severe burns, and infections caused by viruses, fungi or bacteria. Severe physical stress from physical work or competitive sports and certain medications can also bring this about. Thus, over time, carnitine deficiency can develop in organs and tissues [17,18,19,20].
The consequences of carnitine deficiency
In most deficiencies of essential nutrients, fatigue and listlessness are the symptoms. However, with zinc deficiency, for example, there are other typical symptoms such as brittle nails with white spots and grooves and brittle hair. This is also the case with a deficiency of carnitine! Due to a slowed muscular metabolism, muscle weakness and muscle pain are common symptoms here. In case of a pronounced deficiency over a longer period of time, even muscle necrosis (the irreversible death of muscle tissue) and/or fatty liver can be the consequence .
Supplement? If yes, please do it right!
So, as a dietary supplement, L-carnitine can perform various functions. However, there are several problems with conventional supplements. The bioavailability of L-carnitine from food is believed to be around 75%, with the amount of carnitine influencing bioavailability. However, the bioavailability of L-carnitine from dietary supplements (in the range of 1 to 6 g) is only between 5-18%. Thus, in the worst case, just 0.3 g at 6 g intake enters the body, with larger amounts probably even less .
Besides the fact that most of this costly compound does not reach the body at all, there is another major drawback. L-carnitine, whether in steak or supplement form, can be converted by certain intestinal bacteria into the toxic substance trimethylamine. This, in turn, can be converted in the liver to toxic TMAO (trimethylamine N-oxide) The TMAO enters the blood, where it promotes the formation of deposits on blood vessel walls, which in turn can increase the risk of heart attack or stroke . A burger (200g of ground beef) contains just about 100 mg of carnitine . Thus, the concern about what consequences can result from oral supplementation (which can be as high as 6 grams in some exceptional cases!) is well founded. That is why L-carnitine is preferably given as an infusion by physicians and alternative practitioners, especially when the supply of larger doses is necessary. Therefore, in the case of carnitine, it makes sense to rely entirely on liposomal technology! Packaged in liposomes, up to 98% of the active ingredient can be absorbed without having to resort to an injection. This circumvents several problems that can occur with conventional supplementation.
When taking food supplements, you should also make sure that only pure L-carnitine is used, which corresponds to the natural form in our bodies. Cheap products that also contain D-carnitine are strongly discouraged. D-carnitine is toxic and can disrupt membrane transport and even promote an L-carnitine deficiency.
Thus, the exact opposite is achieved what is supposed to be achieved with an L-carnitine supply and more harm than good is caused [25,26]. That is why we at ActiNovo use only the Carnipure® brand, which is produced by the Lonza company from Switzerland. Our Carnitine has the highest quality standards and contains only 100% pure L-Carnitine. The liposomal product is suitable for vegetarians, vegans and allergy sufferers!
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