If you're feeling lethargic, L-carnitine can help. The nutrient, sometimes called simply carnitine, enables our heart and other muscles to make energy, eliminate toxic by-products, and continue to function well as we live longer. Our bodies make L-carnitine from the amino acids lysine and methionine, found in proteins, but we don't always produce enough—especially when faced with physical challenges such as exercise or anything that stresses the heart, including diabetes and heart disease. Plus, our natural ability to produce L-carnitine decreases as we get older.
How It Works
Each of our cells contains mitochondria, tiny components that generate energy. They’re like microscopic furnaces that use fatty acids as fuel. L-carnitine acts as a cargo train, transporting the fatty acids to the mitochondria and taking away the trash—by-products of the process that would be toxic if left in the cell. Without sufficient L-carnitine, mitochondria can’t function optimally, and energy suffers.
Mitochondria also play a key role in aging because they contain their own DNA, separate from the overall cell. According to studies published in the Journal of the American Medical Association and other scientific publications, mitochondrial DNA influences cell regeneration and death. And if that DNA is damaged, cells don’t function as they should—they may die prematurely or mutate—and the aging process accelerates. Keeping mitochondria healthy is considered one of the key strategies for longevity, and L-carnitine is a necessary ingredient.
Studies have shown that L-carnitine helps the heart work more efficiently. For example, research presented at a conference sponsored by the National Institutes of Health in Bethesda, Md., included these findings:
Other research findings include:
L-Carnitine and Drugs
Two types of drugs may work better with L-carnitine: Cholesterol-lowering statins and medications that lower blood sugar for type 2 diabetics. Studies used 2 grams daily of L-carnitine with a statin, and 1 gram twice daily of acety-L-carnitine with diabetes drugs.
Other studies show that L-carnitine may reduce side effects of AZT, used to treat HIV or AIDs, as well as doxorubicin, a type of chemotherapy for cancer.
L-carnitine can be found in food, chiefly red meats, but not in sufficient quantities to produce therapeutic effects. Most studies have found that beneficial doses of L-carnitine range from 1—3 grams daily. To obtain just 1 gram, you would need to eat about 2.3 lbs. of beef each day! So supplements are definitely the way to go.
L-carnitine isn't a stimulant, so it doesn't cause jitters or other caffeine-like effects. It's absorbed more efficiently on an empty stomach, but if you experience discomfort, take it with a meal of carbohydrates and fats, as the amino acids in proteins will compete for absorption.If you are healthy, take 500 mg once or twice daily.
If you have diabetes, prediabetes, or heart disease, take up to 3 g daily in divided doses. Start with a lower dose and increase gradually.
Bluebonnet liquid l-carnitine (Carnipure) in Natural Vanilla Flavor is an easy-to-swallow form of the amino acid that can easily be added to smoothies or juice. Also available in raspberry and orange flavors.
NOW Foods l-carnitine delivers 500 mg of Carnipure L-carnitine per tablet. This formula is 100 percent vegetarian and free of common allergens, including gluten, corn, soy, milk, and eggs.
One capsule of Source naturals l-carnitine gives you 500 mg of Carnipure, a proprietary and high-quality form of L-carnitine. Source Naturals also offers the amino acid in other strengths (e.g., 250 mg).