Fuel Your Heart – Keep the Beat Strong:Nutrient L-Carnitine May Energize Heart Muscle

The heartbeat is essential to life because it propels oxygen- and nutrition-rich blood to tissues throughout the body. To maintain a healthy heartbeat, hundreds of research studies every year look at disease prevention measures – including supplementation with nutrients like L-Carnitine (ehl-car-nih-teen) – that may spare the heart from disease. Still, conditions like coronary heart disease and congestive heart failure (CHF) affect nearly 18 million Americans.¹

The heart requires an abundant supply of energy for proper function and disease prevention. In fact the heart derives about 70 percent of its energy from the burning of fatty acids.² Since the nutrient
L-Carnitine is responsible for shuttling fatty acids into the powerhouse of our cells, where they can be burned for fuel, the heart is consequently dependent on L-Carnitine for most of its energy production.³

L-Carnitine is a cofactor in metabolism, without which, our metabolic cycle will pass over fats and seek out carbohydrates as a energy source, which are short lived, and protein from muscle tissue, our least efficient energy resource. As the body resorts to protein as a resource for energy, all our muscles, including the heart itself, are at risk of weakening.

Research shows that L-Carnitine, as an adjunct to traditional medical therapy, may protect the heart in several ways and over time. The following research examples suggest that L-Carnitine may reduce incidence of chest pain (angina) and/or the extent of muscle damage caused by a heart attack. For those people with exercise-induced angina, it may also help increase tolerance to exercise – also well-known to benefit heart health – by increasing the length of time people can exercise before the onset of chest pain.

Reducing/Eliminating Chest Pain; Increasing Exercise Tolerance
Several scientists have studied the effect of L-Carnitine supplementation on frequency and severity of anginal pain. Dr. Cacciatore studied patients with previously diagnosed exercise-induced angina for six months. Given 2,000 milligrams (mg) of L-Carnitine per day, he observed them for irregular heartbeat patterns (arrhythmias) and their tolerance to exercise. He found that his supplemented subjects showed both significant and progressive improvement in cardiac function and quality of life during the six months of treatment.⁴ Cherchi and Kamikawa reported similar observational studies of men with exercise-induced angina who both increased their total exercise workload and the time it took for their usual symptoms of angina or heartbeat malfunctions to occur.⁵, ⁶ Cherchi also saw 22 percent of his patients become free of angina altogether.

Sparing Muscle After a Heart Attack
Similarly, though the mechanisms of action are unknown, L-Carnitine administration may also spare invaluable heart muscle loss in the days and months following a heart attack. Dr. Singh has studied the effect of supplementing cardiac patients with L-Carnitine immediately following a heart attack. Incidence of angina, arrhythmia, cardiac events including non-fatal heart attacks and cardiac deaths for the first 28 days post-heart attack were significantly less frequent in the L-Carnitine supplemented group, when compared with a placebo group.⁷ Strengthening these findings, Jacoba monitored post-heart attack patients for three months following their heart attack. His subjects’ heart strength was monitored via resting stress test after a one-month recovery period and again after another two months of supplementation with 3,000 mg of L-Carnitine per day. His findings show that the extent of heart muscle viability was greater in the supplemented patients than those receiving placebo.⁸

In a longer-term study, similar in design, Davini studied patients with L-Carnitine supplementation (4,000 mg of L-Carnitine per day) for 12 months post-heart attack. Throughout the study period, the subjects given L-Carnitine showed an improvement in heart rate, blood pressure, anginal attacks, arrhythmias, heart beat strength and lower incidence of mortality (1.2 percent compared with 12.5 percent among the control group). ⁹

Improving the Heart Pump in Congestive Heart Failure
In people who already have weak or damaged hearts such as those with CHF, L-Carnitine may help to improve their outcome in two ways. First, because L-Carnitine supports efficient energy generation from fat, supplementing CHF patients with the nutrient may provide the compromised heart with power to beat more efficiently. In addition, efficient energy production from fat could help forgo the risk of weakening the heart further; a risk because the body uses short-lived carbohydrates for energy, after which, it seeks out protein in muscle, putting the heart muscle itself at risk of being broken down for energy. This risk is reduced when fat resources are efficiently utilized.

Three studies in particular monitored subjects with chronic CHF both with and without L-Carnitine supplementation. Each found a beneficial effect on the heart; each in different ways. Dr. Steger observed improved heart pumping action at supplemental levels of 3,000 mg of L-Carnitine per day.¹⁰ Kobayashi found overall improved heart condition and improved tolerance to activity with supplemental levels of 900 mg per day.¹¹ Dr. Ghidini studied the effect of 2,000 mg of L-Carnitine per day and reported reduced heart rates, less inappropriate bodily collection of fluid (edema), increased ability for the body to rid itself of extra fluid and less shortness of breath.¹²

Where Is L-Carnitine Found?
L-Carnitine is produced in small quantities in the human body (approximately 20 mg of
L-Carnitine is produced daily), but this amount is equivalent to only about 10 percent of the nutrient used daily by the average person and only a fraction of the amount needed by people with cardiac illness. In addition, a daily diet including two to three servings of lean meat such as lamb and beef as recommended in the food guide pyramid, can provide approximately 100-300 mg of L-Carnitine. ¹³, ¹⁴

However, in order to reap the benefits of cardiac protection, additional L-Carnitine may be needed, typically above the level that can be obtained through eating L-Carnitine rich foods. Supplemental
L-Carnitine is usually seen as a single nutrient or in formulations marketed for enhancement of exercise and metabolism. Single nutrient supplements generally contain levels associated with health benefits, offering a range between 250-500 milligrams of L-Carnitine. Health food stores, pharmacies and supermarkets throughout the U.S. carry L-Carnitine supplements.

Lonza, Inc. founded the L-Carnitine InfoCenter to provide credible and reliable information on L-Carnitine for health professionals, educators and communicators. Lonza manufactures pharmaceutical grade L-Carnitine, approved by an Expert Panel as Generally Recognized as Safe (GRAS). Additional information can be found in the Human Nutrition center at www.carnitine.com.

References:

1. U.S. Department of Health and Human Services National Center for Health Statistics. http://www.cdc.gov/nchs/fastats: 4/3/03.
2. Famularo G, et al. Chapter 6. In: Carnitine Today. Landes Bioscience. USA. 1997.
3. Bremer J. Chapter 2. In: The Carnitine System. A New Therapeutical Approach to Cardiovascular Diseases. Kluwer Academy Publishers, The Netherlands. 1995
4. Cacciatore L, et al. The therapeutic effect of L-Carnitine in patients with exercise-induced stable angina: a controlled study. Drugs Exp Clin Res 1991. 18(4): Pp 355.
5. Cherchi A, et al. Effects of L-Carnitine on exercise tolerance in chronic stable angina: a multicenter, double-blind, randomized, placebo controlled crossover study. Int J Clin Pharm Ther Tox 1991. 23(10); Pp 569-572.
6. Kamikawa T, et al. Effects of L-Carnitine on exercise tolerance in patients with stable angina pectoris. Jpn Heart J 1984. 25(4): Pp 587-597.
7. Singh R, et al. A randomized, double-blind, placebo-controlled trial of L-Carnitine in suspected acute myocardial infarction. Postgrad Med J 1996. 72: Pp 45-50.
8. Jacoba K, et al. Effect of L-Carnitine on the limitation of infarct size in one-month postmyocardial infarction cases. Clin Drug Invest 1996. 11(2): Pp 90-96.
9. Davini P, et al. Controlled study on L-Carnitine therapeutic efficacy in post-infarction. Drugs Exp Clin Res 1992. 18(8): Pp 355-365.
10. Steger T, et al. 1996. Effects of L-Carnitine on left ventricular function in patients with chronic heart failure. In Carnitine – Pathobiochemical Basics and Clinical Applications. Ponte Press, Germany.
11. Kobayashi A, et al. L-Carnitine treatment for congestive heart failure: experimental and clinical study. Jpn Circ J 1992. 56: Pp 86-94.
12. Ghidini O, et al. Evaluation of the therapeutic efficacy of L-Carnitine in congestive heart failure. Int J Clin Pharm Ther Tox 1988. 26: Pp 217-220.
13. Leibovitz, B et al 1993. J Opt Nut. 2:90.
14. DiPalma. L-Carnitine: Its Therapeutic Potential