Methionine

Methionine is an essential amino acid that assists in the breakdown of fats, thus helping to prevent a buildup of fat in the liver and arteries that might obstruct blood flow to the brain, heart, and kidneys. The synthesis of the amino acids cysteine and taurine may depend on the availability of methionine. This amino acid helps the digestive system; helps to detoxify harmful agents such as lead and other heavy metals; helps diminish muscle weakness, prevent brittle hair, and protect against radiation; and is beneficial for people with osteoporosis or chemical allergies. It is useful also in the treatment of rheumatic fever and toxemia of pregnancy.

Methionine is a powerful antioxidant. Methionine is a good source of sulfur, which inactivates free radicals. Methionine is also good for people with Gilbert's syndrome, an anomaly of liver function, and is required for the synthesis of nucleic acids, collagen, and proteins found in every cell of the body. Methionine is beneficial for women who take oral contraceptives because it promotes the excretion of estrogen. It reduces the level of histamine in the body, which can be useful for people with schizophrenia, whose histamine levels are typically higher than normal.

As levels of toxic substances in the body increase, the need for methionine increases. The body can convert methionine into the amino acid cysteine, a precursor of glutathione. Methionine thus protects glutathione; it helps to prevent glutathione depletion if the body is overloaded with toxins. Since glutathione is a key neutralizer of toxins in the liver, this protects the liver from the damaging effects of toxic compounds.

An essential amino acid, methionine is not synthesized in the body, and so must be obtained from food sources or from dietary supplements. Good food sources of methionine include beans, eggs, fish, garlic, lentils, meat, onions, soybeans, seeds, and yogurt. Because the body uses methionine to derive a brain food called choline, it is wise to supplement the diet with choline or lecithin (which is high in choline) to ensure that the supply of methionine is not depleted.

Methionine can increase the neurotransmitters dopamine, norepinephrine and epinephrine. Used for hypertension control; reduces allergic symptoms; relieves chronic pain; reduces inflammation; lowers cholesterol; protects from bad effects of aspirin; beneficial in treating Parkinson's and schizophrenia.

Where is it found ?

Meat, fish, and dairy are all good sources of methionine.

Who is likely to be deficient ?

Most people consume plenty of methionine through a typical diet. Lower intakes during pregnancy have been associated with neural tube defects in newborns, but the significance of this is not yet clear.

How much to take

Amino acid requirements vary according to body weight; however, average-size adults require approximately 800-1,000 mg of methionine per day-an amount exceeded by most Western diets. Therefore, most people would not benefit from methionine supplementation.

Side effects

Animal studies suggest that diets high in methionine, in the presence of B vitamin deficiencies, may increase the risk for atherosclerosis (hardening of the arteries) by increasing blood levels of cholesterol and a compound called homocysteine. This idea has not yet been tested in humans. Excessive methionine intake, in the presence of inadequate intake of folic acid, vitamin B6, and vitamin B12, can increase the conversion of methionine to homocysteine-a substance linked to heart disease and stroke. However, whether this relationship creates a significant hazard for humans taking supplemental methionine has not been established. Supplementation of up to 2 grams methionine daily for long periods of time has not produced any serious side effects.

Back To Top