Facts
Why methionine is good for you
Methionine is a sulfur containing essential amino acid which assists in the breakdown of fats and so prevents the build-up of fat in the arteries.
Methionine also assists with the health of the digestive system and removes heavy metals from the body. Since methionine can be converted to cysteine (which is a precursor to glutathione), it is a prime detoxifier of the liver.
Important methionine facts
- Methionine is important in the process of methylation where methyl is added to compounds in order to detoxify the body and it organs (it has a role in heavy metal detoxification, as well as liver detoxification)
- Methionine is a precursor to the amino acids cystine and cysteine
- Methionine is a great antioxidant as the sulphur it supplies inactivates free radicals in the body
- Methionine is one of the three amino acids (cysteine and cystine are the other two) needed by the body to manufacture creatine monohydrate, which is essential for energy production and muscle building
- The sulphur in methionine is useful to assist in maintaining healthy skin tone, well-conditioned hair and strong nails
Methionine works best with
Health
Methionine and health
- Women and oestrogen – methionine has been shown to help excrete excess oestrogen from the liver, so may be beneficial for women taking oral contraceptives.
Talk to a medical professional about methionine supplements before taking them
Deficiency
Groups at risk of methionine deficiency
- People on low protein diets – people who are not eating enough protein foods may not get enough methionine in their diet
- Vegans and vegetarians – people who are on a strict vegetarian diet may suffer from a methionine deficiency if their diet is deficient in protein
People in these groups at risk of methionine deficiency should talk to a medical professional about methionine supplements before taking them.
Symptoms of methionine deficiency
Symptoms of deficiency include:
- fatty liver
- slow growth
- weakness
- oedema (fluid retention)
- skin lesions
Severe deficiency of methionine can cause dementia-like symptoms.
Food sources
Methionine in food
| FOOD | AMOUNT | Methionine (mg) |
|---|---|---|
Tuna, canned in oil | 1 can (171g) | 1474 |
Snapper, cooked | 1 fillet (170g) | 1322 |
Halibut, cooked | 1/2 fillet (159g) | 1256 |
Chicken breast meat only, roasted | 1 cup (140g) | 1203 |
King mackerel | 1/2 fillet (154g) | 1186 |
Round beef, 0% fat, cooked | 100g | 941 |
Pink salmon, cooked | 1/2 fillet (124g) | 939 |
Yellow fin tuna, cooked | 100g | 887 |
Alaskan king crab | 1 leg (172g) | 886 |
Blue fin tuna, cooked | 100g | 885 |
Lean shoulder lamb, cooked | 100g | 875 |
Turkey, light meat only, roasted | 100g | 874 |
Turkey, breast only, roasted | 100g | 871 |
Lean veal leg, cooked | 100g | 857 |
Romano cheese | 100g | 852 |
Lean pork loin chops, cooked | 100g | 825 |
Gruyere cheese | 100g | 822 |
Goat cheese, hard | 100g | 813 |
Daily intake
Methionine recommended daily intake (RDI)
| RDA | 49mg/kg body weight (infants) 32mg/kg body weight (children) 13mg/kg body weight (adult) |
|---|---|
| TOLERABLE UPPER LIMIT | 200-800mg |
| TOXIC LEVELS | No information available |
Toxicity
Overdosage, toxicity and cautions for methionine
There are no known drug or nutrient interactions associated with methionine.
Avoid taking more than the recommended amount of methionine, particularly if the diet is low in folic acid, vitamin B6, or vitamin B12, as conversion of methionine to homocysteine could be promoted. (Homocysteine is a potentially harmful blood fat that has been linked to atherosclerosis – hardening of the arteries).
Precautions
Precautions
People with a serious illness, are breastfeeding or pregnant should only take methionine under the care of a health care professional
Interactions
Interactions
References
References
- Osiecki H, Meeke F, Smith J, The Encyclopaedia of Clinical Nutrition – Volume 1: The Nervous System, BioConceps Publishing QLD 2004
Last reviewed and updated: 8 May 2024
