By Vitaminstuff :
Carnitine, or L-carnitine, is an amino acid manufactured in the body from the essential amino acids lysine and methionine. L-carnitine helps carry fatty acids into the mitochondria in cells so that they can convert these acids to energy. There is a high concentration of carnitine in the heart, which is not surprising, since the heart relies on fatty acids for the fuel it needs to pump blood throughout your entire body.
Many studies have shown that L-carnitine supplementation can help the heart function more efficiently in those that have been diagnosed with heart disease. However, it is important to keep in mind that participants in these studies used L-carnitine in conjunction with their prescribed medications, not in place of them. Researchers believe that supplemental carnitine may help treat people suffering from myocardial infarction, heart failure, angina pectoris, and any other diseases that result from an inadequate blood supply to the heart (ischemia). Some studies indicate that L-carnitine also helps to lower blood triglycerides and LDL (bad) cholesterol and raise HDL (good) cholesterol.
L-carnitine has been shown to ease the symptoms of Alzheimer’s disease, depression, and Chronic Fatigue Syndrome (CFS), a disorder characterized by both extreme fatigue and depression. Researchers think carnitine may help treat these disorders by boosting cellular energy production and improving overall brain function. Acetyl-L-carnitine (ALC) is a form of carnitine needed to produce acetylcholine, the neurotransmitter that helps the brain function properly, particularly where memory is concerned.
Because ALC levels decline with age, it has been theorized that taking ALC supplements may help slow the progress of Alzheimer’s and dementia in the elderly by improving memory and cognitive ability. ALC supplements were found to be even more effective when combined with phosphatidylserine (PS) supplements. Studies in rats suggest ALC supplementation may help prevent many symptoms associated with aging, including a decline in energy metabolism and memory. ALC supplementation worked even better in these studies when it was combined with alpha-lipoic acid. Studies attempting to replicate these results in humans are currently underway.
L-carnitine has been linked to enhanced athletic performance and endurance. So far, studies have not shown it to be capable of doing either, but there is some research indicating that L-carnitine can make sperm more vital and active. L-carnitine is highly concentrated in the epididymis, where sperm are manufactured and stored in the body. Study participants that took 3 grams of L-carnitine supplements each day saw significant improvement in sperm mobility, when doses are taken regularly for 3 to 4 months. Thus, L-carnitine may be an effective treatment for some cases of male infertility, and further studies are underway.
Carnitine got its name because it was first discovered in meat (carnus). Meat, poultry, fish, and dairy products are the richest sources of L-carnitine. Fruits, vegetables, and grains contain relatively little L-carnitine, so vegetarians may want to supplement this nutrient. Premature infants may also be at increased risk of L-carnitine deficiency when fed soy-based formulas, so look for formulas are L-carnitine fortified.
There are some people who may have hereditary conditions that keep them from absorbing L-carnitine. Systemic carnitine deficiency and myopathic carnitine deficiency are genetic disorders that usually present symptoms, such as muscle pain or weakness, or decreased kidney and heart function, in infancy or early childhood. For these people, intravenous L-carnitine is available by prescription only.
Others wishing to supplement L-carnitine for its cardiovascular, cognitive, or anti-aging benefits have a lot of options available to them. Acetyl-L-carnitine (ALC) is available without a prescription as a nutritional supplement. In addition to providing L-carnitine, it provides acetyl groups that help produce the important neurotransmitter, acetylcholine. ALC also comes as a powder that can be stirred into water or juice. L-carnitine is also available in supplements without a prescription. Supplemental doses usually range from 500 to 2,000 milligrams each day.
No toxic effects related to L-carnitine overdose have been reported to date, although less serious side effects, such as mild nausea, abdominal cramps, and diarrhea, may occur. Supplements providing more than 3,000 milligrams each day may cause a “fishy” body odor. Acetyl-L-carnitine has been reported to increase agitation in some Alzheimer’s disease patients, and to increase seizure frequency and severity in some individuals with seizure disorders.
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