Amino Acids

Better Nutrition, Sept, 1999 by Brenda Adderly

Carnitine.

Actually a cousin of the true amino acids, carnitine is not involved in the protein-building business, but in the body's fat-burning functions, especially in liver cells and heart muscles.

Benefits. Research has shown that carnitine can help with overall weight loss and improve high triglyceride levels, making it a potent weapon in the battle against both obesity and heart disease.

Dietary sources/nutrients. Carnitine is primarily found in meat, so vegetarians are at risk for deficiencies. Still, the body can manufacture carnitine if it has access to sufficient amounts of vitamins B-1 and B-6, as well as iron and the amino acids lysine and methionine. Vitamin C is also necessary for carnitine production, and several recent studies have shown that deficiencies of this vitamin are fairly common, particularly in the elderly, men who live alone, people who smoke, and college students.

Dosage. Typical starting doses of carnitine supplements are 1 to 3 g per day.

Glutamine.

Benefits. Our muscles have more glutamine in them than any other amino acid, which is why this substance is often taken by body builders. But it is also one of the few things that can cross the "blood-barrier" and stimulate mental processes like learning and alertness. In addition, glutamine can ease the symptoms of alcohol withdrawal and sugar cravings. It is also frequently used as a remedy for arthritis, tissue damage, and connective tissue diseases, as well as for intestinal ailments, like peptic ulcers.

Dietary sources/nutrients. Raw spinach and parsley are good dietary sources of glutamine. Although many vegetables and meats contain glutamine, it cannot survive cooking.

Dosage. Supplements of 5 to 10 g daily are within the acceptable range, although anyone with kidney problems or cirrhosis of the liver should not take glutamine.

Lysine.

Benefits. Cold sore sufferers know (or should know) about lysine, an essential amino acid that prevents fever blisters. In addition, researchers have recently found that people with herpes viruses -- which cause chronic fatigue syndrome and other illnesses -- can benefit from lysine's ability to block arginine, a necessary element in herpes virus reproduction. Lysine is a key element when it comes to repairing tissue and forming new collagen, the protein that provides support for the skin and connective tissues.

Absorbability. Calcium absorption also requires lysine, as does sugar metabolism.

Dosage. Dosages vary with individual situations.

Phenylalanine.

Benefits. Alertness, optimism, and ambition are all connected to the essential amino acid phenylalanine. This substance is essential for the production of norepinephrine, epinephrine, and L-dopa, substances which are essential for proper functioning of the central nervous system. Phenylalanine can also be converted to phenylethylamine, a mood-elevating compound. Studies have shown that phenylalanine also plays a role in weight loss, by reducing the appetite, and has been used to alleviate pain in conditions such as arthritis, menstrual cramps, and migraines.