L-Carnitine(L -肉堿)可以防止低密度脂蛋白(LDL)的氧化

Keep LDL in Check with L-Carnitine

LDL cholesterol is known far and wide as the "bad" cholesterol, but in fact that’s a bad rap. The truth is we need cholesterol, including the LDL kind. But when free radicals in the body oxidize LDL cholesterol it does indeed turn from friend to foe, building up in artery walls -- it is one of the substances that lay the foundation for dangerous plaque. 

Recently an Italian study demonstrated that one way to reduce oxidized LDL levels is by supplementation with the amino acid derivative L-carnitine. Researchers randomly assigned 81 patients with diabetes (who are prone to cholesterol problems) to one of two treatment groups. One group received placebo and the other received 2 g of L-carnitine once daily. At the end of three months, the L-carnitine-treated patients showed a decrease of oxidized LDL levels compared with the placebo group. This was just the latest study on L-carnitine.

THE MANY USES OF L-CARNITINE

According to Mark Stengler, ND, regular contributor to Daily Health News, L-carnitine helps with various health problems and its benefits are not limited to people with diabetes. When I spoke with Dr. Stengler, he rattled off an impressive list of benefits, noting that L-carnitine -- or carnitine as it is also called -- helps get energy to the heart muscles and is therefore beneficial to a number of cardiac conditions (angina, ischemia-induced arrhythmias, cardiomyopathy and congestive heart failure). It has also been used as therapy for myocardial infarction to help minimize muscle damage as a result of the oxygen reduction... it is helpful for chronic fatigue syndrome and kidney and liver disease... and there’s yet more. Studies have shown that carnitine (in the form known as acetyl-l-carnitine) may help ease the discomfort of peripheral neuropathy, a condition often triggered by diabetes or chemotherapy drugs that causes nerves in the feet and sometimes the hands to develop painful burning and stinging sensations. It appears that carnitine may even help peripheral nerves regenerate, though this is a preliminary finding. A variety of small studies have looked at the possibility that carnitine also boosts athletic performance given its role in energy production, but thus far none has shown any positive effect. However, Dr. Stengler told me that several of his patients who engage in endurance sports such as long-distance running seem to benefit from it. Dr. Stengler says people with elevated LDL but who do not have diabetes can also benefit from taking carnitine to help them prevent LDL oxidation from taking place.

HOW TO GET CARNITINE INTO YOUR BODY

Carnitine is naturally produced in the body by the liver and kidneys and is stored in the skeletal muscles, brain and heart, but, as is so often the case, production diminishes with advancing age. You can obtain carnitine through food, in particular red meat. Steak or hamburger has three times the amount of carnitine as does pork, another high source. Lesser dietary sources include dairy products, chicken, fish and avocado. It may be a good idea for vegetarians and vegans to consider carnitine supplementation. Additionally, Dr. Stengler says people who suffer from muscle fatigue and cramps may possibly have a carnitine deficiency. For such complaints, he orders a blood test to measure carnitine levels in the tissue and red blood cells, weighs this data against patient reporting, and treats accordingly.

CARNITINE SUPPLEMENTATION

For adult patients who have chronic fatigue, congestive heart failure or angina, Dr. Stengler often prescribes dosages of 1,000 mg, taken two or three times daily. Higher dosages of up to 2,000 mg a day may even be a good idea for people with high LDL levels, he says, but the body can’t absorb any more than this at a time. A reported side effect is occasional digestive upset. Carnitine is considered quite safe. Dr. Stengler decreases the dosage or directs the carnitine to be taken with meals for those who find this to be a problem. As always, if you are interested in taking carnitine and most especially if you take any drugs or supplements, be sure to discuss this with your doctor before you start.

Source(s):

Mark Stengler, ND, a naturopathic physician and leading authority on the practice of alternative and integrated medicine. He is author of Bottom Line/Natural Healing newsletter, author of The Natural Physician’s Healing Therapies (Bottom Line Books), director of the La Jolla Whole Health Clinic in La Jolla, California, and adjunct associate clinical professor at the National College of Natural Medicine in Portland, Oregon. To learn more about his work, visit www.drstengler.com.