GENERAL DESCRIPTION:
Methionine is an essential amino acid that is
required for the absorption,
transportation, and bioavailability of zinc and selenium in
the body. Methionine also
facilitates the breakdown of fats and prevents accumulation of fat in the liver and
arteries. Methionine is obtained in the diet from
Brewer’s yeast, dairy products, eggs, fish, meat, seafood, and whey.
ROLE FOR ANTI-AGING:
Methionine appears to prevent bacteria from
adhering to the wall of the bladder; this property
of methionine has led to it being suggested as a treatment for recurrent urinary tract infections
(UTI’s). One trial has found evidence to support this claim,
yet the use of methionine in preventing UTI’s has not been
confirmed. Methionine has been shown to
be effective in the prevention of acetaminophen toxicity,
and some experts have suggested selling acetaminophen in combination with the amino acid to
prevent acetaminophen poisoning. However, there has been
some speculation that chronic use of methionine can
increase homocysteine levels.
DEFICIENCY SYMPTOMS:
Methionine deficiency can cause apathy, loss of pigmentation in hair, edema, lethargy, liver
damage, muscle loss, fat loss, skin lesions, weakness, and
slowed growth in children.
THERAPEUTIC DAILY AMOUNT:
Not established, however one study which used methionine supplements to treat urinary tract
infections, found that 500mg taken three times a day had a
therapeutic effect.
MAXIMUM SAFE LEVEL:
established
SIDE EFFECTS/CONTRAINDICATIONS:
Some research suggests that methionine may help to relieve some symptoms of Parkinson’s
disease. However, several studies have found that
S-adenosylmethionine (SAMe) – another form of methionine –
worsens symptoms of the disease. Therefore some experts suggest that Parkinson’s disease patients should avoid taking methionine and SAMe at
present. Furthermore, methionine may interfere with the
absorption or action of the anti-Parkinson’s drug
levodopa.
Animal studies suggest that a high intake of
methionine, in the presence of B-vitamin deficiencies, may increase the risk of developing atherosclerosis by increasing blood cholesterol and
homocysteine levels. People taking supplementary methionine
should ensure that they obtain recommended amounts of folate, vitamin B6, and vitamin B12.
People with kidney disease or liver disease should consult
their doctor before taking methionine.
