Alpha

Methionine

General Cancer

Colorectal Cancer

Summary

Methionine is classified as an essential amino acid that helps the body absorb, break down and eliminate fat. It is necessary for the production of glutathione (an anti-oxidant), and amino acids cysteine and taurine. Methionine is lipotropic, and helps prevent the accumulation of fat in the liver, and thus ensures normal liver function. It, along with cysteine and taurine, eliminate toxins from the body. Methionine is needed to make creatine, which supports all muscular function. It is also essential for the formation of healthy collagen (which forms skin, nails, and connective tissues). Since methionine helps reduce the level of inflammatory histamines, supplementation with methionine is beneficial for conditions linked to excessive histamine production, such as arthritis and chronic allergies. Rich sources are beans, eggs, fish, meat, garlic, onions and lentils. Recommended daily intake of L-Methionine is 13mg/kg or 1 gram/day for adults.

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Abstracts

General Cancer

Malignant cells fail to utilize homocysteine (HCYS) in place of methionine (MET) and they are dependent on exogenous MET for growth.

o Cancer Lett. 2006 Feb 28; 233(2): 195-207.

Colorectal Cancer

Adequate intake of folate, methionine, riboflavin, and vitamin B-6 may prevent aberrant DNA methylation and thereby protect against colorectal cancer (CRC)……. Within the Netherlands Cohort Study on diet and cancer (n = 120,852), 2349 cases and 4168 subcohort members were available for data analyses from a follow-up period of 13.3 y after baseline……. Our findings suggest that relatively high methionine intake may protect against proximal colon cancer in men and rectal cancer in women but that folate may not have a protective effect.

o De Vogel, S et al (2008).Dietary Folate, Methionine, Riboflavin, and Vitamin B-6 and Risk of Sporadic Colorectal Cancer. J Nutr, 138(12), 2372-8.

Accumulation of DNA methylation abnormalities, observed during progression of human colorectal neoplasia, may be influenced by certain dietary factors……. Low dietary folate and methionine and high intake of alcohol may reduce levels of S-adenosylmethionine, which is required for DNA methylation…….. We assessed dietary intake for a 1-year period for women of the Nurses' Health Study, started in 1976, and for men of the Health Professionals Follow-up Study, started in 1986….. Folate, alcohol, and methionine could influence methyl group availability, and a methyl-deficient diet may be linked to early stages of colorectal neoplasia. A dietary pattern that increases methyl availability could reduce incidence of colorectal cancer.

o Giovannucci, E et al (1993).Folate, methionine, and alcohol intake and risk of colorectal adenoma. J Natl Cancer Inst, 85(11), 875-84.

Methylation of DNA, which may have a role in the regulation of gene expression, depends on dietary folate and methionine… We assessed dietary intake for a 1-year period for a cohort of 47,931 U.S. male health professionals, 40-75 years old and free of diagnosed cancer in 1986…findings support the hypothesis that substantial consumption of alcohol, when combined with inadequate intakes of folate and methionine, may increase risk of colon cancer and confirm similar findings in adenomas.

o Giovannucci, E et al (1995).Alcohol, low-methionine--low-folate diets, and risk of colon cancer in men. J Natl Cancer Inst, 87(4), 265-73.

This part of the case-control study was designed to identify dietary factors associated with colorectal cancer risk in 715 incident cases compared with 727 age/sex frequency-matched randomly chosen community controls, in which a quantitative assessment of all foods eaten was made….. These data support the proposition that a diet containing the dietary micronutrients involved in DNA methylation (folate, methionine, and vitamins B6 and B12) and some of those with antioxidant properties (selenium and vitamins E and C) may have a role to play in lowering colorectal cancer risk and also that such protection can be achieved by dietary means alone.

o Kune, G, & Watson, L (2006). Colorectal cancer protective effects and the dietary micronutrients folate, methionine, vitamins B6, B12, C, E, selenium, and lycopene. Nutr Cancer, 56(1), 11-21.