Methionine is an essential amino acid that is not synthesized by the body and must be obtained from food. It is one of the sulphur containing amino acids and is important in many body functions. Through its supply of sulphur, it improves the tone and pliability of the skin, conditions the hair and strengthens nails. The mineral sulphur also protects the cells from airborne pollutants, such as smog, slows down the aging process in the cells, and is involved with the production of protein.
Methionine is essential for the absorption and transportation and bioavailability of selenium and zinc in the body. It also acts as a lipotropic agent to prevent excess fat buildup in the liver, and is an excellent chelator of heavy metals, such as lead, cadmium and mercury, binding them and aiding in their excretion from the body.
It can help fatigue and may be useful in some cases of allergy because it reduces histamine release. It has also been used in the treatment of rheumatic fever and toxemia resulting from pregnancy. Recent studies show methionine deficiencies may be associated with the development of age related cataracts, and supplements may delay their development. In Parkinson’s disease patients taking L-Dopa, it was found that additional supplements with L-Methionine may further decrease the tremors and rigidity that limit normal activities.
The best food sources are beef, chicken, fish, pork, soybeans, eggs, cottage cheese, liver, sardines, yogurt, pumpkin seeds, sesame seeds and lentils. The range of human need for methionine is estimated at between 800 and 3,000 milligrams per day. This represents a 3.7 fold variation, based on a sample of 29 individuals.