L-carnitine: uses, benefits, side effects
1 min
L-carnitine occurs naturally in the human diet in a variety of foods, particularly red meat. The Western diet is estimated to provide 100-300 mg of L-carnitine per day.
In Europe and the United States, however, dietary intake of L-carnitine has fallen by about 20% over the last decade, mainly because of a decrease in beef consumption.
The role of L-carnitine in fat metabolism can be summed up simply: it turns fat into energy. More precisely, L-carnitine is essential for transporting long-chain fatty acids across the mitochondrial membrane for the subsequent breakdown of fat and the generation of energy.
In addition, with a sufficiently high concentration of free L-carnitine inside them, mitochondria can maintain the energy-generating processes that depend on the availability of free coenzyme A. If only a little free coenzyme A is available, L-carnitine can temporarily bind acetyl units and thus ensure that more energy is generated.
L-carnitine can also support the excretion of acids, a function that may be important after intense physical exercise or in certain metabolic conditions.
Because of its fundamental role in energy metabolism, L-carnitine is typically
used by the body to support functions with a high energy requirement.
In this sense, L-carnitine supplementation plays a role in heart health, male fertility and healthy ageing, as well as for infants, pregnant women and vegetarians.
Weight control
L-carnitine supplementation has been found to increase fatty acid oxidation in healthy human subjects. In two different studies, subjects received labelled fatty acids with a meal, before and after ten days of L-carnitine supplementation (3 g/day). The breakdown product of the labelled fatty acids, labelled CO2, was then measured in exhaled air. In the group that received carnitine tartrate, a significant increase in exhaled labelled CO2 was observed, indicating a significant increase in fatty acid oxidation (fig. 1). This leads to the conclusion that carnitine may offer weight-loss benefits in weight-control programmes.
Recovery after exercise
Studies show that carnitine supplementation can support recovery after exercise.
Researchers observed reduced free radical production, less tissue damage and reduced muscle soreness after exercise in recreationally trained athletes after 3 weeks of carnitine.
Carnitine supplementation has been found to increase muscle oxygen consumption, providing a potential mechanism for reducing hypoxic stress after endurance exercise. It follows that L-carnitine-based supplements can provide considerable benefits, without significant side effects or contraindications.
In Europe and the United States, however, dietary intake of L-carnitine has fallen by about 20% over the last decade, mainly because of a decrease in beef consumption.
The role of L-carnitine in fat metabolism can be summed up simply: it turns fat into energy. More precisely, L-carnitine is essential for transporting long-chain fatty acids across the mitochondrial membrane for the subsequent breakdown of fat and the generation of energy.
In addition, with a sufficiently high concentration of free L-carnitine inside them, mitochondria can maintain the energy-generating processes that depend on the availability of free coenzyme A. If only a little free coenzyme A is available, L-carnitine can temporarily bind acetyl units and thus ensure that more energy is generated.
L-carnitine can also support the excretion of acids, a function that may be important after intense physical exercise or in certain metabolic conditions.
Because of its fundamental role in energy metabolism, L-carnitine is typically
used by the body to support functions with a high energy requirement.
In this sense, L-carnitine supplementation plays a role in heart health, male fertility and healthy ageing, as well as for infants, pregnant women and vegetarians.
Weight control
L-carnitine supplementation has been found to increase fatty acid oxidation in healthy human subjects. In two different studies, subjects received labelled fatty acids with a meal, before and after ten days of L-carnitine supplementation (3 g/day). The breakdown product of the labelled fatty acids, labelled CO2, was then measured in exhaled air. In the group that received carnitine tartrate, a significant increase in exhaled labelled CO2 was observed, indicating a significant increase in fatty acid oxidation (fig. 1). This leads to the conclusion that carnitine may offer weight-loss benefits in weight-control programmes.
Recovery after exercise
Studies show that carnitine supplementation can support recovery after exercise.
Researchers observed reduced free radical production, less tissue damage and reduced muscle soreness after exercise in recreationally trained athletes after 3 weeks of carnitine.
Carnitine supplementation has been found to increase muscle oxygen consumption, providing a potential mechanism for reducing hypoxic stress after endurance exercise. It follows that L-carnitine-based supplements can provide considerable benefits, without significant side effects or contraindications.
