L-carnitine[edit | edit code]
| What is L-carnitine | |
| L-carnitine is an essential acid produced in the liver from the amino acids lysine and methionine. It is necessary for energy production and fat metabolism. It is also found in meat and dairy products. Many brands of supplements are sold as acetyl-L-carnitine, which is a more absorbable form of L-carnitine. | |
| Effect of L-carnitine | |
| The main role of L-carnitine is to transport fatty acids to the mitochondria (the energy stations of cells), where they are used for energy. The point of taking the supplement is to increase carnitine levels and therefore improve fat burning. In theory, this would be beneficial for weight control as well as endurance. Increased utilization of fat for energy during exercise could help conserve muscle glycogen and thereby delay the onset of fatigue. However, despite advertising claims, there is very little scientific evidence to support these theories. While initial studies conducted in the 1980s suggested a positive effect on performance, more recent studies have failed to confirm that L-carnitine supplements increase fat burning or improve endurance. | |
| Do you need it? | |
| Because the evidence supporting the claims made for acetyl-L-carnitine is limited, this supplement cannot be recommended for athletes as a performance enhancer. | |
| Side effects | |
| Carnitine is a dietary precursor of trimethylamine, which in turn, if the manufacturer’s recommended intake of carnitine is exceeded, leads to the formation of trimethylamine in quantities that the human enzyme system is not capable of processing. Due to the presence of unmetabolized trimethylamine in the blood, the body is forced to excrete it through urine, sweat, and exhaled air. Thus, exceeding the recommended dosage of carnitine leads a person to the disease “Trimethylaminuria”. The first symptoms of this disease are the smell of fish emanating from the patient’s body, urine and exhaled air smell similar. The patient usually does not feel the smell that comes from him. In case of trimethylaminuria due to an overdose of L-carnitine, it is necessary to urgently stop taking the drug in order to avoid damage to the liver cells responsible for the production of the enzyme flavin monooxygenase-3. As a rule, the fishy smell goes away 3-4 days after stopping the drug. |
10 facts about carnitine
L-carnitine
(English L-carnitine, also levocarnitine. Mistakenly [1] called vitamin Bt, vitamin B11) - a natural substance related to B vitamins, performs a number of important functions in the body, is not a fat burner, but is a transporter of adipose tissue to muscle mitochondria, where during aerobic exercise this adipose tissue is converted into energy.
L-carnitine is often called a vitamin-like substance, but it is not a vitamin, since the body can synthesize it on its own. The level of L-carnitine is homeostatic, all its excess is effectively eliminated from the body, and it does not accumulate beyond measure.
L-carnitine was first isolated by V. S. Gulevich and R. Z. Krimberg in 1905. In 1962, the physiological role of carnitine was revealed - it transports long-chain fatty acids into mitochondria through the inner membrane.
According to physical properties, L-carnitine is a white crystalline powder, hygroscopic, highly soluble in water. There are two stereoisomeric forms: L-carnitine and D-carnitine. Only the L-form has biological activity. D-carnitine is harmful to the body because it is a competitive antagonist of L-carnitine.
In the human body it is present in muscles and liver.
Biosynthesis of levocarnitine[edit | edit code]
L-carnitine is synthesized in the liver and kidneys, from which it is transported to other tissues and organs. The synthesis of levocarnitine occurs with the participation of vitamins C, B3, B6, B9, B12, iron, lysine, methionine and some enzymes. If there is a deficiency of at least one of the components, L-carnitine deficiency may develop with impaired body functions. This, however, is rarely observed, often due to a genetic defect in the enzymes responsible for the synthesis of L-carnitine.
What products does it contain?
L-carnitine is a water-soluble molecule and can therefore be excreted naturally through urine. Because of this, in patients on dialysis, its content in the body is too low. As a result, such patients must take supplements or receive L-carnitine intravenously. During dialysis, nutrients and compounds are removed from the body, causing deficiencies to develop.
In addition, due to the high solubility of L-carnitine in water, some of it is lost during the cooking process.
Functions and effects of L-carnitine[edit | edit code]
Fat Burning
L-carnitine transports fatty acids (structural elements of fat) into the mitochondrial matrix, where they are destroyed and energy is released. Supplementing with L-carnitine is done in hopes of increasing the breakdown of fat.
Increased mental and physical energy
As shown by the results of a double-blind, placebo-controlled study conducted in 2007 in Italy, the administration of L-carnitine at a daily dose of 2 g for 6 months led to increased mental and physical activity. The subjects noted improved mood, increased endurance and increased overall tone. [2] In fairness, it should be noted that for most athletes the results of this study are hardly indicative due to the fact that the subjects in it were 66 people aged from 100 to 106 (!) years.
Resistance to stress
ON L-Carnitine
Research has proven the effectiveness of carnitine in increasing tolerance to stress and increasing the adaptive capabilities of the human body. [3]
Detoxification
L-carnitine maintains the level of free CoASH, which is involved in the detoxification of organic acids and xenobiotics, is necessary for the functioning of certain enzymes and for the normal functioning of the Krebs cycle.[4]
Anabolic functions
The anabolic effect of L-carnitine was established experimentally; during experiments using this supplement, scientists noticed that the subjects not only lost fat, but at the same time increased lean muscle mass. The mechanism of this action is still not fully understood, however, there are a number of theories that explain the anabolic effect of carnitine by its participation in phospholipid metabolism, optimization of the Acetyl-CoA/CoASH balance, greater use of fat as an energy source, and improvement of neurotransmission. [5]
Reduces cholesterol
L-carnitine reduces bad cholesterol, thereby preventing the narrowing of blood vessels in the heart and brain, and prevents heart attacks and strokes. [6]
Protects the heart and blood vessels
First of all, this effect is realized by reducing the level of cholesterol, which affects small coronary vessels. In addition, L-carnitine improves myocardial metabolism and has an antioxidant effect. Clinical studies have shown that after a course of carnitine, people with heart disease had fewer complaints, and myocardial function improved. [7]
Other effects
L-carnitine has neuroprotective, antihypoxic, antioxidant and antithyroid effects, prevents apoptosis and osteoporosis, and also stimulates tissue regeneration. [8]
L-carnitine: harm and side effects[edit | edit code]
Read the main article:
L-carnitine: harm and side effects
The effectiveness of using additional doses of L-carnitine has been questioned by a number of researchers. Thus, according to a meta-analysis, the low effectiveness of L-carnitine in athletes was shown [9]. For women who are overweight, carnitine (4 g/day) in combination with regular cardio exercise (4x30 min/week) was shown to be ineffective [10]
Health of beautiful people
Many sources also report the benefits and harms of carnitine for a woman, especially if she is a new mother and breastfeeding. The feeding process, unfortunately, reduces the amount of this natural supplement in the body.
Therefore, young mothers have slightly higher levels of native L-carnitine than the average person. This is how nature intended it to compensate for this loss. That is why, to ensure stable homeostasis in the body of a nursing mother, additional intake of carnitine is desirable, for which, of course, it is better for her to eat certain foods and closely monitor the intake of dietary supplements in order to avoid an overdose. Moreover, it is better to consult a doctor about taking the supplement.
L-carnitine in sports[edit | edit code]
Review of the Scientific Evidence on Carnitine
Carnitine is important in cases where it is necessary to increase general and special endurance in aerobic sports (running, swimming, rowing, etc.) (refuted: Appl. Environ. Biol. Sci., 1 (12) 695-699, 2011 , confirmed: Ayer, Vol 2, 2015[11]). If the athlete is not concerned about losing weight, maximum energy gain can be achieved by combining levocarnitine with an increased amount of fat in the diet. There is a special high-fat diet that is prescribed simultaneously with large doses of carnitine. This method of enhancing bioenergy is especially preferable when it is necessary to avoid loss of body weight during training.
Levocarnitine helps increase endurance in both aerobic and anaerobic (powerlifting, bodybuilding, etc.) sports. It should be noted that the anabolic effect of levocarnitine can be masked by a general drop in body weight as a result of the disappearance of subcutaneous and internal fat tissue. Therefore, when assessing the anabolic effect of carnitine, one should be guided by criteria other than indicators such as body weight and limb volume. In this case, it is the percentage of fat mass and total body mass.
To achieve maximum effect, levocarnitine should be used along with a well-balanced diet and training program. Levocarnitine is not a dope and can be used in sports nutrition without any restrictions.
In the absence of initial synthesis disorders in the body, it is recommended to use it in short courses, since with long-term use a withdrawal syndrome is observed - the production of its own levocarnitine decreases and there is a need to constantly take the exo-drug.
L-carnitine for muscle protection[edit | edit code]
L-carnitine for muscle protection
Translation from English and text adaptation: Andrey Zavyalov
A daily dose of 2 grams of L-carnitine protects athletes' muscles from breakdown, according to a study by sports scientists at the Islamic Azad University in Iran, published in the Journal of Asian Sports Medicine.
Researchers divided 22 physically active young people into two groups. One group took a placebo for two weeks. The other group took a supplement containing 2 g of L-carnitine. Two weeks later, the researchers conducted a test 15-minute run. The researchers also analyzed the subjects' blood: before taking the supplement (Base), immediately before the race (Pre), immediately after the race (Post), after 2 hours (2H) and after 24 hours (24H).
results
During the race, the concentration of markers of muscle destruction - the enzymes lactate dehydrogenase (LDH) and creatine kinase (CK) - increased in the blood of the subjects, but this increase was noticeably lower in athletes taking carnitine. It turned out that L-carnitine reduces the degree of damage to muscle cells.
TBARS
(thiobarbituric acid reactive compound - TBARC) is a marker of free radical activity. These harsh molecules, released during intense physical activity, can damage cell structure. During the race, the concentration of TBARS in the blood of the subjects increased, but the increase was noticeably lower in athletes who took L-carnitine.
Conclusion
Two weeks of oral L-carnitine supplementation has some mitigating effects on lipid peroxidation, muscle cell damage, and increased antioxidant activity. However, the exact mechanism of attenuation of oxidative stress markers by L-carnitine has not been established and requires further study.
Where to find carnitine
Where to find L-carnitine and why look for it? Unlike creatine (a product similar in name and similar in functionality), l-carnitine is found in excess in meat products, in particular red meat. However, in meat and generally in its natural form, carnitine is practically useless. Lipolic acid is in it in its neutral form and only if the body needs accumulation or synthesis will it be transformed.
Eating a huge piece of steak may not be good for you. Due to active catabolic processes occurring over a long period of time, the body can produce D-carnitine, which has an extremely detrimental effect on muscle growth, endurance and other indicators.
Therefore, it is better to take carnitine in sports supplements. There are several forms of release:
- In liquid form. This is actually ready-made carnitine with the fastest possible action - it guarantees an energy boost 15 minutes before training. It is expensive, has high bioavailability and low efficiency.
- In powder form. The best option for athletes, as it allows you to independently regulate the dosage of the amino acid. The only condition is that carnitine must be taken 40 minutes before training.
- In the form of capsules and tablets. A useless and unnecessary drug that is sold in pharmacies. Low efficiency, low bioavailability, zero effect.
- As a component for energy drinks. Carnitine as a component increases the transfer functions of cells, which stabilizes and prolongs the effects of the energy drink.
- As a pre-workout component.
Rating of sports nutrition with L-carnitine[edit | edit code]
- Magic Elements L-Carnitine Liquid 3000
- L-Carnitine Concentrate by Multipower
- L-Carnitine from Power System
- L-Carnitine from NOW
- L-Carnitine 500 from Optimum Nutrition
- NitroPump from GEON
- L Carnitina Body Line
- Cura de slabire cu Carnitina de la Body Line
The data was obtained by analyzing numerous reviews found on sports nutrition forums, as well as the price/quality ratio.
Combination with other additives[edit | edit code]
L-carnitine goes well with all types of fat burners, potentiates their effect and reduces the incidence of side effects. L-carnitine can also be taken during weight gain cycles, in order to prevent fat formation, taking it with protein, gainer and any other complexes.
The combined use of carnitine and coenzyme Q10 preparations is considered effective, since their action is aimed at 2 main points of application: reactivity (L-carnitine) and resources of the psychological system (coenzyme Q10).[12]
Should you exercise?
The evidence that L-carnitine has a positive effect on athletic performance is somewhat mixed. However, several studies report modest benefit with higher or longer doses.
The effect of L-carnitine may be indirect and may take weeks or months to manifest itself. What sets this compound apart from supplements such as caffeine or creatine, which can improve athletic performance in the most direct and immediate way.
But there are already proven benefits of carnitine for both women and men:
- Recovery. A very important aspect for the body if you have just been doing physical activity.
- Oxygen supply to muscles. Strengthens and accelerates their saturation with oxygen.
- Endurance. Increases blood flow and nitric oxide production, helping to reduce discomfort and fatigue.
- Muscle soreness. Reduces pain and discomfort after training.
- Production of red blood cells. They are responsible for transporting oxygen throughout the body and muscles.
Method of application[edit | edit code]
The optimal doses of carnitine are from 500 mg to 2 g per day (usually a single dose is 500 or 750 mg in 3 divided doses, or 1000 mg in 2 divided doses). There is no point in exceeding 2 g, as studies have not shown any benefit from higher doses. Take L-carnitine 30 minutes before training and in the morning on an empty stomach. On days off from training, also take in the morning and afternoon - between meals and on an empty stomach. It is in the morning and during physical activity that L-carnitine is most active.
About fat burning
In theory, using this compound, namely carnitine type L, as a weight loss supplement makes sense.
Because L-Carnitine helps move more fatty acids into cells to burn energy, most people believe this benefit will increase their ability to burn fat and lose weight.
However, the human body is extremely complex, and the results of experiments are ambiguous.
For example, in an eight-week study of 38 women who exercised four times a week, there was no difference in weight loss between those who took L-carnitine and those who did not. Moreover, five participants taking the supplement experienced nausea or diarrhea.
Another human study tracked the effects of L-carnitine on fat burning during a 90-minute spin class. Four weeks of supplementation did not increase fat burning.
However, one analysis of nine studies, mostly in obese or elderly people, found that they lost an average of 1.3 kg more weight using the supplement.
Carnitine is best taken when people who are obese or elderly are primarily on a careful diet and regular exercise regimen.
Links[edit | edit code]
- Bremer, J. Carnitine - metabolism and functions. Physiol. Rev., 1983, 63, 1420-1480.
- https://www.ajcn.org/cgi/content/abstract/86/6/1738?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=Malaguarnera&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
- Klyuchnikov S.O., Ilyashenko D.A., Klyuchnikov M.S. Rationale for the use of L-carnitine and coenzyme Q10 in adolescents // Issues of modern pediatrics. - 2008. - T. 7. - No. 4.
- Kuzin V.M. Carnitine chloride (25 years in clinical practice) // Breast Cancer. – 2003. – No. 10.
- Seim H, Eichler K, Kleber H. L(-)-Carnitine and its precursor, gamma-butyrobetaine // Nutraceuticals in Health and Disease Prevention. – New York: Marcel Dekker, Inc.; 2001. – R.217–256
- Malaguarnera M., Cammalleri L., Gargante M. et al. L-Carnitine has a positive effect on the health of centenarians = L-Carnitine treatment reduces the severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial / / American Journal of Clinical Nutrition. - 2007. - T. 86. - No. 6. - P. 1738-1744.
- Löster H. Carnitine and cardiovascular diseases. – Bochum.: Ponte Press Verlags-GmbH, 2003
- Steiber A, Kerner J, Hoppel C (2004). "Carnitine: a nutritional, biosynthetic, and functional perspective." Mol. Aspects Med. 25 (5-6): 455–73.
- https://www.ajcn.org/cgi/content/full/72/2/618S/T2
- https://www.ncbi.nlm.nih.gov/pubmed/10861338
- Mostafa Dehghani, Saeid Shakerian, Sedigheh Heidari Nejad, Mohammad Kazem Gharib-Naseri. Effects of L-Carnitine L-Tartrate Acute Consumption on Lipid Metabolism, Maximum oxygen consumption (VO2 max), and distance run Following Aerobic Exhaustive Exercise on Treadmill in Elite Athletes wrestling. Ayer, Vol 2, 2015
- Klyuchnikov S.O., Ilyashenko D.A., Klyuchnikov M.S. Rationale for the use of L-carnitine and coenzyme Q10 in adolescents // Issues of modern pediatrics. - 2008. - T. 7. - No. 4.
The benefits and harms of carnitine
The benefits of L-carnitine are manifested in:
- Normalization of blood flow.
- Strengthening the body's defenses.
- Reducing chronic fatigue syndrome.
- Reducing catabolic processes during drying.
- Improving mental abilities.
- Positive effect on liver function.
- Fast muscle recovery after training.
- Reducing the level of bad cholesterol, thereby preventing the formation of plaques in the blood vessels.
- It is an anabolic agent.
deficiency manifests itself in side effects, but in rare cases: fatigue, muscle weakness and drowsiness. Possible states of confusion.
With amino acid deficiency, performance decreases. Depression and apathy arise. Possible low blood pressure.
Hidden threat
L-carnitine supplements at 3 grams per day have potential side effects such as nausea and vomiting, cramps, and diarrhea. They may also accidentally disturb your social life because taking so much per day can cause a fishy body odor.
People with kidney disease or epilepsy should take special care with L-carnitine supplements or energy drinks containing it. This is because the substance can cause muscle weakness or cramps. However, some research suggests that the supplement may be important for people on certain types of dialysis.
The benefits and harms of carnitine are ambiguous, so if you have a desire to purchase this dietary supplement, consult a specialist.
