Carnitine is an essential amino acid for fat metabolism that helps increase metabolic flexibility, reduce systolic blood pressure and waist circumference. Athletes using carnitine have been found to increase their measured performance by 11% in a 30-minute trial. While skeletal muscle uses fatty acids at rest and light exercise, the brain uses fat to meet up to 90% of its energy needs.
As gut bacteria metabolize choline and carnitine, it raises TMAO levels, which are thought to trigger heart disease. However, some experts believe that TMAO is a marker for hepatic insulin resistance, which is the true cause of associated health conditions. A cyclical ketogenic diet with intermittent fasting helps maintain normal weight, improves metabolic flexibility and reduces hepatic insulin resistance. Astaxanthin, krill oil, and berberine supplements are also beneficial for liver insulin resistance.
A recent meta-analysis found that when taking carnitine supplements, men and women experienced improvements in waist circumference and blood pressure, two biomarkers of metabolic syndrome. Metabolic syndrome is a condition characterized by a number of physical factors, including:
• Wide waist circumference indicative of high levels of visceral fat around the organs
• High blood sugar or insulin resistance
• High triglyceride
• Low levels of high-density lipoprotein (HDL) cholesterol
Metabolic syndrome is diagnosed when a person has three or more of these factors that predispose to many chronic diseases, including Type 2 diabetes, cardiovascular disease, Alzheimer’s disease, fatty liver disease (NAFLD), and more.
The presence of insulin resistance is a primary factor in the metabolic syndrome, which has reached epidemic proportions as the US diet becomes more dependent on polyunsaturated fatty acids (PUFAs) and added sugars. PUFAs can be found in vegetable oils, edible oils, seed oils, and plant oils, including sunflower, safflower, soybean, corn, and other popular oils.
While recent research has determined how carnitine and choline can improve fat metabolism and metabolic flexibility, it’s important to note that taking a supplement cannot overcome the damage done to your body by a lean diet rich in processed sugars, PUFAs, and processed foods.
Carnitine to Improve Metabolic Syndrome Factors
Carnitine is an amino acid found in the body. You get most of the carnitine that the body uses from your diet or supplements, and it’s essential for fat metabolism for energy. A recent review of the literature on carnitine was published in the journal Nutrients, in which scientists analyzed the results of nine randomized controlled trials.
The trials that the researchers included in the analysis recorded measurements of waist circumference, fasting blood sugar, blood pressure, triglyceride levels, or HDL cholesterol. Studies have used supplementation doses between 0.75 grams (gm) and 3 gm per day for eight to 24 weeks. The researchers found that the supplement was linked to a reduction in systolic blood pressure and waist circumference. They suggested that metabolic syndrome biomarkers (MetSyn) could improve with a dose of 1 gm to 3 gm of carnitine per day.
Carnitine Improves Impaired Fat Metabolism
Understanding how the body burns fuel has practical applications for athletic performance and preventing metabolic conditions. There is a complex system that regulates how the body burns carbohydrates and fats. Carnitine plays an important role in fat metabolism and has been studied and used to improve exercise performance.
Researchers and athletes have found that short-term supplementation with carnitine has little effect on fat metabolism. However, published in the Journal of Physiology, Dr. In a study led by Benjamin Wall, data showed that supplementing for six months increased muscle carnitine levels by 21%.
As described in another article in the Journal of Physiology, research has shown differences in lactate and carnitine levels after low-intensity exercise and high-intensity exercise. It reduced the body’s use of glycogen and the activity of pyruvate dehydrogenase complex (PDC), which occurs during low-intensity exercise carnitine. This compound mediates carbohydrate metabolism.
In other words, individuals with higher carnitine did not burn muscle glycogen, but instead continued to burn fat for energy. During high-intensity exercise, the muscles produced less lactate when the participant had more carnitine and increased PDC activity. Beginning in the 1980s, researchers began to better understand the role lactate plays in exercise.
As energy demand increases with exercise, glucose-burning muscle fibers form pyruvate as a product of the reaction. When pyruvate production exceeds the muscles’ capacity to consume it, pyruvate is reduced to lactate and then transported to oxidative muscle fibers where it can be used as fuel. The work led by Wall led to subsequent studies that have implications for athletic performance and show that carnitine has an effect on improving metabolic flexibility. One study evaluated whether carnitine supplementation could alter metabolic flexibility and insulin sensitivity in people documenting impaired glucose tolerance.
Eleven volunteers underwent a randomized, placebo-controlled, double-blind study in which they followed a 36-day regimen comparing a placebo or carnitine intervention. The available data showed that carnitine supplementation helped restore metabolic flexibility in people with impaired glucose tolerance.
Muscle Fiber Depends on Fat Metabolism
It’s important to note that in the Wall-led study, participants who took carnitine supplements increased their athletic performance and work output by 11% in a 30-minute performance trial. The researchers explained this improvement by the “dual role of carnitine, which at low intensities preserves glycogen and at high intensities reduces muscle lactate accumulation”.
In other words, work output was more efficient and performance was better as muscles burned fatty acids for energy. This is also demonstrated by symptoms of carnitine deficiency, which may include muscle weakness, fatigue, and shortness of breath or swelling if the heart is affected.
Many cells in the body use fatty acids for energy production. In fact, your heart muscle cells use fat metabolism to meet 90% of their energy needs. During rest and light-intensity exercise, fat metabolism is the main source of energy for your skeletal muscles. 14 Therefore, the ability to efficiently and effectively burn fat for fuel can increase metabolic flexibility and reduce the potential risk of insulin resistance.
Both choline and carnitine help burn fat. In one study, scientists evaluated the effect on energy production with supplementation of one or both, with or without exercise. Researchers followed 19 female participants and found that the interactive effects of supplements previously documented in animal models were also present in human participants.
Scientists discovered that when participants were supplemented with more choline than they would normally get from their diet, the body retained carnitine in tissue, which increased fat metabolism in participants. When small amounts of carnitine were then added for seven days, urinary excretion of carnitine returned to normal, and the researchers believed that the muscle stores of carnitine were sufficient.
Interestingly, when exercise was added, they improved exercise performance and decreased participants’ body weight, but not body fat. The data led the researchers to conclude that ranking choline and carnitine supplementation results in incomplete fat metabolism and increased energy wastage with light exercise.
Does Choline and Carnitine Raise TMAO Levels?
The gut microbiota metabolizes choline and carnitine to produce trimethylamine, which in turn is metabolized to trimethylamine n-oxide (TMAO). Some studies have associated TMAO production with an increased incidence of cardiovascular disease, prediabetes, and thrombosis. However, James DiNicolantonio, Pharm.D. In an article published by , he and colleagues showed that the likely cause of the high levels is not ingestion of carnitine and choline, but rather hepatic insulin resistance. According to DiNicolantonio, an important factor is the significant elevation of TMAO via the flavin-containing monooxygenase-3 enzyme (FMO3). Dinicolantonio suggests that high FMO3 activity in the liver may reflect insulin resistance in the organ, which in turn influences cardiovascular health risk.
Cyclic Ketogenic Diet Improves Metabolic Flexibility
If high TMAO increases the risk of cardiovascular disease and is indeed a reflection of hepatic insulin resistance after consuming foods high in carnitine, what can it do to correct it and reduce your risk. The two strategies that are most helpful for achieving this goal and increasing metabolic flexibility are a cyclical ketogenic diet and intermittent fasting. It should be done together for best results. He may also consider some supplements that may be useful in the treatment of hepatic insulin resistance and therefore reduce the potential damage from TMAO.
In the body, this functions like metformin, a drug commonly used to treat diabetes. Both work, at least in part, by activating adenosine monophosphate-activated protein kinase (AMPK). Known as the “metabolic master switch,” AMPK is an enzyme that controls how energy is produced in the body and how it is used by cells. By activating this enzyme, it helps regulate biological activities that normalize lipid, glucose and energy imbalances. Berberine, used in Chinese medicine to treat diabetes, has also been shown to counteract hepatic insulin resistance in diabetic rodents.
It is a powerful carotenoid antioxidant with activity like the cholesterol-lowering drug fenofibrate. It indirectly stimulates AMPK in your liver and has been shown to reduce hepatic insulin resistance in animals fed high-fat diets and reduce the risk of cardiovascular events in patients with metabolic syndrome.
This includes the esterified form of astaxanthin, which increases its bioavailability, and long-chain omega-3 fats, which are essential for health, including heart health.
Writer: Ozlem Guvenc Agaoglu