L-carnitine is an amino acid derivative that has an important function in human metabolism. It is made from the amino acids lycine and methionine and is found in the heart, skeletal muscle, and liver. L-carnitine functions as a transporter, allowing long-chain fatty acids to enter mitochondria, the energy-producing organelles of cells. It allows fatty acids to undergo beta-oxidation, which breaks them down to produce ATP, the body's primary energy currency, enabling a wide range of physiological tasks such as muscular contraction, neuron transmission, and cellular operations.
L-Carnitine plays a vital role in energy production within the body by enabling the transportation of long-chain fatty acids into cell mitochondria. Once inside the mitochondria, these fatty acids are oxidised to generate energy. Additionally, L-Carnitine acts as a transporter for removing toxic compounds from the mitochondria, preventing their buildup in these cellular organelles.
Organs with high energy demands, such as the heart and skeletal muscles, contain a significant concentration of mitochondria. These organs rely on fatty acids as a fuel source to meet their energy needs.
While most individuals naturally produce sufficient amounts of carnitine, certain individuals, such as infants or those with medical or genetic conditions, may have inadequate production. This insufficiency can lead to symptoms like muscle weakness, clumsiness, vomiting, and confusion.
Due to its essential role, carnitine is considered a necessary nutrient. Therefore, supplementation with carnitine is required to fulfil the body's demands when natural production is insufficient or impaired.
L-carnitine has grown in popularity as a dietary supplement due to its potential advantages for a variety of aspects of human health, athletic performance, and recuperation.
Furthermore, L-carnitine supplementation may help with certain medical issues. It is occasionally used as a prescription to treat primary and secondary carnitine deficiencies, which can affect energy metabolism and cause symptoms such as muscle weakness.
Different Types of Carnitine and Their Potential Benefits
1. ALCAR (Acetyl-L-carnitine): ALCAR Acetyl-L-carnitine is another form of carnitine that has neuroprotective qualities. It can pass the blood-brain barrier and enter the central nervous system, where it can be useful. ALCAR has been shown to improve cognitive performance, sustain brain function, and protect against age-related cognitive decline. It may also enhance mood and relieve symptoms of depression.
2. D-Carnitine: According to research, D-Carnitine may help reduce fat formation and promote liver health. It has anti-inflammatory properties, which can be beneficial for people who have liver inflammation. It should be noted, however, that D-Carnitine should only be used under medical supervision because excessive doses can interfere with the body's natural carnitine levels.
3. L-Carnitine L-Tartrate (LCLT): LCLT is a highly bioavailable version of carnitine that is often used in sports supplements. Because of its quick absorption rate, it is useful for improving athletic performance and helping with easy recovery. LCLT supplementation has been shown in studies to help reduce exercise-induced muscle damage and muscular soreness and promote muscle repair and adaptability. Some researchers believe that LCLT can help people recover from exercise-induced exhaustion and improve their overall exercise capacity.
4. Glycine propionyl-L-carnitine (PLC) is a carnitine derivative that has been researched for its potential benefits in cardiovascular health and pain management. It has been shown to increase blood flow, increase exercise tolerance, and relieve symptoms in those with peripheral artery disease. PLC may potentially have anti-inflammatory qualities, which could benefit people with rheumatic diseases. It has shown potential for alleviating angina symptoms and promoting overall heart health.
L-Carnitine Function in the Human Body
L-Carnitine transports the fatty acid chain into the mitochondrial matrix, allowing the cells to break down the fat and get energy from fat reserves. It helps reduce oxidative stress, which is why it is proposed as a treatment for many conditions, including heart disease and obesity. Our body needs about 15 mg/day of carnitine from dietary sources and other sources. L-Carnitine helps make adenosine triphosphate (ATP), the cell's energy currency. It enables the efficient oxidation of fatty acids, ensuring a steady supply of ATP for various physiological processes, including muscle contraction, organ function, and cellular activities. Furthermore, it has been proposed that L-carnitine may improve endurance by boosting the use of fat as an energy source and preserving glycogen reserves.
L-Carnitine and Weight Loss
L-carnitine aids in the transfer of fatty acids into the mitochondria, where they are oxidised and used for energy. Hence, increasing L-carnitine levels promotes fat oxidation, which directly leads to weight loss. It also increases exercise performance as it uses fat for energy, which leads to better energy production and expenditure during any physical activity, leading to a greater weight drop. Some studies have also suggested that L-Carnitine promotes satiety and appetite, which helps manage weight and reduces the chances of binge eating. It also affects the levels of certain neurotransmitters, such as serotonin, which regulate our hunger and make us full for longer.
L-Carnitine for Brain Functioning
L-carnitine has antioxidant qualities that can help prevent oxidative stress, which has been linked to age-related cognitive decline and neurological disorders. Several studies have shown L-carnitine and ALCAR can improve energy status, decrease oxidative stress, and prevent subsequent death in adults and brain surgery. Studies have suggested that L-carnitine supplementation may have potential benefits for certain brain-related conditions. L-carnitine, for example, has been studied as a potential supplementary treatment to support cognitive performance in Alzheimer's disease and moderate cognitive impairment.
L-Carnitine for Enhanced Sports Performance
Regular exercise and workouts can both result in muscle damage and pain, decreasing the quality of life. L-Carnitine reduces exercise-induced hypoxia, subsequent muscle damage, and delayed-onset muscle soreness (DOMS). Also, L-carnitine has the potential to increase the utilisation of fat as a fuel source during exercise, sparing muscle glycogen and improving stamina. By taking L-carnitine, there is an increase in maximal oxygen consumption. The human body gets 70% of its energy from fat breakdown, and L-Carnitine gives a boost that improves athletic performance. It also improves blood flow through muscles and other tissues to enhance athletic performance. Moreover, it also boosts the production of vascular and cellular mediators such as nitric oxide, which opens blood vessels known to improve glycemic regulation by increasing peripheral glucose utilisation, which further improves the function of skeletal muscle.
L-carnitine for Type 2 Diabetes
Type 2 diabetes is a chronic disease characterised by insulin resistance and poor glucose metabolism. Studies have suggested that L-Carnitine helps manage Type 2 diabetes by improving insulin sensitivity and glucose disposal in healthy subjects. Furthermore, L-Carnitine plays a primary role in transporting long-chain fatty acids into mitochondria to produce cellular energy, while acetyl coA (a group of coenzymes that metabolise fatty acids) prevents further accumulation of fatty acids and protects the cellular membrane. This improves glucose uptake in muscle cells and regulates glucose levels, which enhances insulin action and reduces markers of inflammation and oxidative stress, factors associated with diabetes.
L-Carnitine for Depression
Depression is a complex mental health condition influenced by various factors, including neurotransmitter imbalances, inflammation, oxidative stress, and genes. It is demonstrated from research studies that L-Carnitine enhances the effectiveness of antidepressant medications. A study published in the Journal of Clinical Psychopharmacology (2013) suggested that L-carnitine supplementation reduces depressive symptoms. L-carnitine is involved in the transport of fatty acids into mitochondria for energy production. Therefore, it has been suggested that L-carnitine supplementation could potentially improve energy metabolism and alleviate depressive symptoms associated with mitochondrial dysfunction.
L-Carnitine for Bone Health
Osteoporosis is a condition caused by reduced bone density. It results in an increased risk of fractures. As we age, we tend to lose bone density, which enhances the chances of bone fractures. L-carnitine has antioxidant properties that regulate the new bone formation mediated by osteoblasts (Cells that build bone). Supplementation with L-carnitine enhances the production of osteoblasts, which helps remodel the bones and reduces the risk of bone density and fractures.
L-Carnitine for Muscle Growth
L-carnitine, being an ergogenic aid, increases exercise capacity by increasing maximum oxygen consumption and alleviating muscle injury. It also improves exercise performance, increases the utilisation of fat as a fuel, and reduces markers of muscle damage and fatigue. It increases blood flow and nitric oxide production in the muscle tissue, which helps delay fatigue. Additionally, it can lead to increased muscle mass, accompanied by a decrease in body weight, and reduce physical and mental fatigue.
L-Carnitine Safety and Side Effects
If L-Carnitine is taken at recommended doses, It is generally considered safe for most people.
However, like any supplement, it can cause side effects in some individuals. Side effects of L-carnitine may include:
1. Some people who use L-carnitine may develop gastrointestinal difficulties such as nausea, vomiting, diarrhoea, or stomach cramps. When consumed on an empty stomach, it may produce acid reflux or heartburn.
2. In some cases, high doses of L-Carnitine can result in a side effect known as "fishy odour syndrome" or "fishy smell syndrome." The fishy smell occurs due to the metabolic breakdown of L-Carnitine into a compound called trimethylamine (TMA). TMA is then further broken down by bacteria in the body to produce trimethylamine-N-oxide (TMAO). After being broken down, it is excreted from various bodily fluids in the form of sweat, urine, and breath.
Who Should Consider Taking L-Carnitine?
1. People with specific carnitine deficiencies, genetic disorders affecting fatty acid metabolism, and certain heart conditions may find L-Carnitine supplementation beneficial.
2. Vegetarians who avoid animal products have seen lower levels of L-Carnitine in their bodies. In these cases, L-Carnitine supplements can help meet their dietary requirements.
3. L-Carnitine is often used by athletes and individuals engaged in physical activities. It enhances exercise performance, aids in recovery, and assists with fat burning.
4. With ageing, the body's natural production and levels of L-Carnitine tend to decline. Some studies suggest that older adults may benefit from L-Carnitine supplementation to potentially improve physical and cognitive function.
In conclusion, L-Carnitine comes in a variety of forms, each with its own benefits. Acetyl L-Carnitine has neuroprotective properties; D-Carnitine helps to reduce fat accumulation; L-Carnitine L-Tartrate is beneficial for sports performance and recovery; and Propionyl-L-Carnitine may help with cardiovascular health and pain management.
