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 By: ISSA Note: This is part two, click here for part one! Carnitine For A Healthy Heart The beneficial effects that carnitine can have on cardiovascular health should be of interest to everyone, but especially to those who are at risk of coronary heart disease. Carnitine is a vital substance needed by your body to keep your heart pumping. Medical researchers have discovered an association between low levels of carnitine in heart muscle and heart failure. It is therefore suspected that low-carnitine production or intake is a risk factor for heart attacks in some people. Among its many "heart healthy" benefits, carnitine can improve blood flow and raise the "good" HDL-cholesterol levels, while lowering the "bad" LDL-cholesterol levels. This reduces your risk of coronary heart disease. So, if you want a healthier heart, if you are recovering from heart problems, or if you just want to reduce your chances of developing such health problems, the following information will give you some of the essential facts you need. Read on to learn how carnitine can help you stay "young at heart."
In the lungs, blood is once again enriched with oxygen. At the same time, carbon dioxide is removed from the blood and expelled from the body. The oxygenated blood then travels back to the heart through the pulmonary vein. There it supplies the heart tissues with oxygen before being pumped, once again, from the heart through the arteries to other parts of the body, completing its circular route. This process is maintained constantly throughout life. The development of arteriosclerosis, a disease characterized by the hardening of the arteries, can compromise the function of the cardiovascular system. In particular, a type of arteriosclerosis, called atherosclerosis, is characterized by the formation of arterial lesions beginning with plaque formation and eventually resulting in the thickening of the blood vessels. This condition restricts, or can even block, blood flow to the heart and other parts of the body. Restriction or blockage of blood vessels that supply blood to the heart can result in a lack of oxygen supply to the heart. Since the heart relies on its supply of oxygen to generate energy for muscle contractions, a decrease in its blood supply, known as myocardial ischema, can cause angina pectoris-a type of chest pain. If the blood flow to the heart becomes very restricted or blocked, a myocardial infarction, or heart attack, will occur. Clinical research and some case studies report an inverse relationship between carnitine levels in the heart and heart failure. In simple terms, this means that the incidence of heart failure can be higher in people whose tissue levels of carnitine are lower than normal. Higher levels of carnitine in cardiac tissues are associated with a lower incidence of heart attack. Carnitine can also protect the body from a reduction in blood flow to the heart, which, as you learned, can impair the heart's function and give rise to heart attack. People who have myocardial ischemia (reduced blood flow to the heart) and those who suffer from the resulting chest pains can benefit from carnitine supplementation. Such people should experience a reduction in pain and improvements in exercise tolerance while taking this supplement. Carnitine has also been shown to benefit people with intermittent claudication-a condition characterized by leg pain due to lack of blood flow to the leg muscles-by improving their walking capacity. Early research conducted on the anti-ischemic effects (improved blood flow) of L-carnitine was performed on laboratory animals. These studies found reduced tissue damage and anti-arrhythmic effects when animal subjects were given L-carnitine. This led to more research, first on animals, then eventually on humans. In both types of studies, mixed results have been reported on the benefits of carnitine administration on heart disease. Some studies show positive results and others show no significant improvements. However, no adverse effects have been reported from L-carnitine use. This indicates that carnitine supplementation will produce either beneficial results or none at all. During the initial discovery of the role of carnitine in heart health, a group of medical researchers looked at the carnitine levels in heart-tissue samples of patients undergoing heart transplants. They discovered that carnitine levels were lower in-patients with chronic heart failure as compared with the control group, which consisted of heart-tissue samples taken from people within four hours of death by natural causes unrelated to cardiovascular reasons. This data supports the inverse relationship between low levels of carnitine in cardiac tissue and increased risk of heart disease. A research study conducted by R. B. Singh and coworkers determined measurable benefits from the use of L-carnitine in doses of 2 g per day for twenty-eight days in study subjects. The study was conducted using 101 people who were diagnosed with suspected myocardial infarction, or heart attack. Subjects were given either 2 g of L-carnitine or a placebo each day. There were no side effects reported due to carnitine use. At the end of the twenty-eight days, the researchers found a reduction of infarct size in the carnitine group. (An infarct is the area of damaged or dead cells resulting from a decrease or lack of oxygen in the tissues due to restricted or blocked blood flow.) The carnitine group also experienced a reduction in angina pectoris; arrhythmia, or irregular heartbeat; nonfatal reinfarction-a repeat episode of a heart attack; and cardiac-related deaths. In another study conducted by P. Davini and coworkers, the effects of 4 g per day of L-carnitine were examined in people with a diagnosis of myocardial infarction. In this study, eighty-one people received carnitine for one year, in addition to routine drug therapy. When compared with control subjects who did not receive carnitine, the carnitine group showed an improvement in heart rate, quality of life, and life expectancy. Studies also show that carnitine can improve exercise tolerance and heart function in people with impaired cardiovascular function. Several studies have shown that carnitine can improve exercise tolerance and heart function in people with problems relating to cardiovascular health. For example, in 1983, Dr. T. Kamikawa and coworkers examined the effects of L-carnitine in doses of 900 mg per day on the exercise performance of people with stable angina pectoris. During the first four weeks, all patients received a placebo. After four weeks, subjects received 900 mg per day of L-carnitine for twelve weeks. Exercise tests were given after the placebo period and after four and twelve weeks of carnitine therapy. Subjects were given treadmill exercise tests to determine if the carnitine administration had any beneficial effects. The researchers found that carnitine supplementation produced improvements in exercise tolerance after just four weeks of supplemental use. Additionally, two of the twelve subjects were free of angina pectoris after the full length of the study period. In another study, reported in 1985 by Cherchi and coworkers, subjects with chronic stable angina pectoris were given either 2 g of L-carnitine per day or a placebo for four weeks. The carnitine subjects showed an increase in exercise work capacity. In yet another study, reported in Circulation in 1988, Dr. G. Brevetti and coworkers found that after three weeks of carnitine therapy, there were improvements in people with intermittent claudication-cramping, pain, and weakness in the legs due to poor circulation. These researchers examined the effects of carnitine on walking distance and found that it improved the walking ability of people with this condition. Most recently, in 1998, Dr. Eric Brass and Dr. William R. Hiatt published their review article titled, "The role of carnitine and carnitine supplementation during exercise in man and in individuals with special needs," in The Journal of the American College of Nutrition. Their review of the scientific literature found that carnitine therapy might improve exercise capacity in people with circulation problems. Taking the right amount of carnitine is important to derive the benefits reported in scientific studies. For nutritional purposes or as part of a cardiovascular-wellness program, 500 to 1,500 mg per day of L-carnitine should maintain tissue levels of carnitine. Lower levels of 100 to 500 mg may also be useful if taken on a regular basis. If you are suffering from a cardiovascular disease or are at risk of developing such diseases, consult your doctor and tell him or her that you are interested in using carnitine and other supplements as part of your nutritional therapy. If your doctor is unfamiliar with the benefits of carnitine, he or she should consult the reference section and read the selected scientific studies. Most cardiologists are familiar with the benefits that carnitine and other supplements have to offer. Therapeutic dosages used in clinical studies that report the most benefits range from 2 to 4 g of L-carnitine per day. Dosages as low as 1 g per day have reported positive results, but at least 2 g per day seem to cause better results. When using carnitine for therapeutic reasons, remember that it is not a substitute for drug therapy and medical supervision. Also, most studies using high dosages of carnitine are conducted for less than a year, so long-term effects of carnitine supplementation remain unknown. However, carnitine has been sold as a supplement for many years now, and no adverse effects have been reported from its use. Other supplements can help with cardiovascular wellness, and include: coenzyme Q10, vitamin E, vitamin C, carotenoids, folic acid, vitamin B6, vitamin B12, garlic, soy protein, bioflavonoids, lipoic acid, pantethine, magnesium, L-arginine, L-taurine, calcium, hawthorn, Ginkgo biloba, grape-seed extract, and Pycnogenol. Of course you should read the available literature on such supplements before you include them in your nutritional regimen. But remember no amount of medication or supplementation will replace the beneficial health effects of following a diet low in fat and high in fiber with plenty of fruits and vegetables. And maintaining a healthy body weight and following a regular exercise program are also very important for cardiovascular health. More Ways Carnitine Can Help There are additional reported benefits of carnitine that you may find interesting. Carnitine helps increase male fertility. In 1979, Norwegian researchers discovered a connection between carnitine levels and sperm viability. But it wasn't until almost two decades later that Italian researchers conducted a landmark study examining the effects of carnitine administration in men with unexplained asthenospermia-a reduction in the vitality of sperm. Dr. M. Costa and coworkers administered 3 g of L-carnitine per day in divided doses of 1 g after each meal to 100 men with asthenospermia for four months. Sperm samples were evaluated at the end of this period, and to the delight of the researchers and the study subjects, an increase in sperm count and sperm mobility was noted. The researchers concluded that oral administration of L-carnitine may improve sperm quality in men with asthenospermia and pointed out that this could be a useful treatment in cases of this mysterious, but common cause of, infertility. In another study, researchers gave 47 men with asthenospermia 3 g of L-carnitine per day in divided dosages of 1 g after each meal for a period of three months. After the three-month study period, 37 of the subjects treated with L-carnitine showed improvements in sperm viability. The researchers also concluded that L-carnitine administration seems worthy in the treatment of asthenospermia without complications. Some other nutrients that appear to be beneficial for boosting male fertility include zinc, vitamin C, vitamin B12, and the amino acid L-arginine. Consult your doctor about the proper use of these nutritional supplements as part of a male infertility treatment program. Furthermore, since studies have shown that alcohol is toxic to the male reproductive system and that the infertility effects of alcohol are partially reversible, it is a good idea to eliminate or limit the consumption of alcohol. In addition, it is a good idea to limit or eliminate the use of tobacco as it may have an adverse effect on fertility, as well. Taking carnitine can also help in some cases of chronic fatigue syndrome. Chronic fatigue syndrome (CFS) is a condition characterized by persistent fatigue. Some of the symptoms of this syndrome include aching muscles and joints, depression, anxiety, irritability, headaches, intestinal problems, and loss of appetite. Researchers from the Chronic Fatigue Syndrome Center in Chicago, Illinois, discovered that blood serum levels of carnitine might be a factor in CFS. Drs. A. V. Plioplys and S. Plioplys reported in the Journal of Neuropsychobiology that the CFS patients they examined had significantly lower levels of carnitine in their bodies than people without CFS. The researchers determined that higher blood serum levels of carnitine correlated with better functional capacity of mitochondria. They also found that CFS patients had more metabolic wastes in their body fluids, which caused the fluids to be acid, instead of neutral, and had abnormal muscle mitochondria with depressed function. CFS patients also demonstrated reduced aerobic capacity. The doctors then speculated that mitochondrial abnormalities might lead to the type of fatigue that is characteristic of people with CFS. This discovery inspired them to test how administration of carnitine supplements would affect CFS patients. So, in 1997, they began a research study to determine if their hypothesis was correct. In this 1997 study, people with CFS were administered 3 g of L-carnitine per day, in three divided doses of l g each, taken after meals, under controlled experimental conditions for eight weeks. Significant improvements in the CFS condition were observed between weeks four and eight. At the end of the eight-week treatment period, researchers found that the carnitine administration had produced improvements, such as increased ability to work, better sleep, improved concentration, and general improvements in physical and mental well being, in the CFS condition. This connection between carnitine deficiency and the abnormalities that can lead to CFS shows that carnitine may help in the treatment of people with CFS, as well as provide others with a possible course of nutritional prevention of CFS. Note: This is part two, click here for part one! References:
Borum, Peggy R, "Role of carnitine during development," Canadian Journal of Physiology and Pharmacology 63 (1985): 571-576.
Author: Daniel Gastelu, M.S., MFS
Reprinted with Permission. Copyright 2004 Daniel Gastelu. All rights reserved. This article is not intended to replace medical advice; consult your doctor for all matters related to your health.
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Before discussing the research on cardiovascular health and carnitine use, it's a good idea to learn a little about the cardiovascular system. The cardiovascular system is made up of the heart and blood vessels-arteries, veins, and capillaries. Oxygen-enriched blood circulates from the lungs to the heart then to other parts of the body through the arteries, delivering oxygen to each living cell. Deoxygenated blood-along with metabolic waste products, such as carbon dioxide-travels through the veins back to the heart, which pumps the oxygen-lacking blood into the lungs.
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