This essential amino acid belongs to the sulphur-containing group with cystein, cystine and taurine. Read general facts about sulphur-containing substances under "Cysteine". There are signs that L-methionine could have been one of the very first organic substances on this planet, one step older than e.g. glutathione.
As is well known, amino acids are the building blocks of life, and research into the origin of life focuses very much on the question of the origin of amino acids. In a famous simulation experiment, a mixture of ammonia, methane and other substances which made up the Earth's early atmosphere was sent through an electrically charged flask, which produced several primitive amino acids. Methionine was one of them. It is also exceedingly and very actively present in the most primitive and therefore oldest life forms - the bacteria. The bacteria can synthesize methionine themselves, unlike humans who have to obtain methionine through their diet.
Methionine functions in the synthesis of other amino acids and in this regard, detoxification and decomposition to other products. This function is closely related to its ability to liberate and receive the so-called methyl groups. In this field, methionine has quite extraordinary potential, which it demonstrates in the bacteria's metabolism, in the synthesis of the other sulphur-containing amino acids, and as an antioxidant and detoxifying agent. The necessary concomitant factors are vitamins B6 (pyridoxine) and B12 (cobalamine), folic acid, plus minerals like magnesium.
Animal tests indicate that methionine deficiency could lead to arteriosclerosis, decomposition of body tissue, inhibited growth, and obstruction of the utilization of folic acid. The latter effect has been confirmed by patient studies, where high levels of histamine could not be reduced by folic acid alone but also required methionine supplements.
Some patients suffering from severe depression sometimes accompanied by schizophrenia get better with methionine supplements, but it is absolutely necessary to, at the same time, administer the concomitant factors, including all the B vitamins. Methionine supplements can cause psychotic symptoms in patients who suffer from a folic acid deficiency.
Methionine removes heavy metals from the body, counteracts fatigue and exhaustion, protects like an antioxidant against free radicals, and detoxifies the liver. Methionine is also necessary for the body's utilization of selenium. Dietary supplements with selenium are often coupled with methionine.
Deficiency leads to an increased risk of infection, cholesterol accumulation, atherosclerosis, and oedema, because the production of urine requires sufficient amounts of methionine in the body. Methionine improves hair growth and memory and counteracts skin and nail illnesses. Like other sulphur-containing amino acids, it has a protective effect against radiation injuries and induces healing.
Therapeutic dosage
1 to 3 g. daily in evenly distributed doses are tolerated by most patients; but take into account cases of possible homocysteine poisoning and vitamin B deficiency. 2/3 of all Parkinson patients show considerable improvement after megadoses of up to 5 g. This amino acid must always be taken with plentiful quantities of vitamin B6 (pyridoxin) and folic acid!
Attention!
Megadoses of methionine can release calcium from the bones and thus worsen osteoporosis. Also be aware of vitamin B deficiency and homocystein poisoning.
Also read "Amino acids generally" and "Amino acid complexes - Protein supplements".
