Methionine

Methionine and Fertility

Methionine more important than other amino acids and nutrients for fertility

Dietary restriction extends healthy lifespan in diverse organisms and reduces fecundity. Adding essential amino acids to the dietary restriction condition increased fecundity and decreased lifespan, similar to the effects of full feeding, with other nutrients having little or no effect. However, methionine alone was necessary and sufficient to increase fecundity as much as did full feeding, but without reducing lifespan.

http://www.nature.com/nature/journal/v462/n7276/full/nature08619.html

Methionine and Birth Defects

Restricting methionine from diet causes birth defects

We report on the effects of restricting the supply of specific B vitamins (i.e., B(12) and folate) and methionine, within normal physiological ranges, from the periconceptional diet of mature female sheep. We observed no effects on pregnancy establishment or birth weight, but this modest early dietary intervention led to adult offspring that were both heavier and fatter, elicited altered immune responses to antigenic challenge, were insulin-resistant, and had elevated blood pressure-effects that were most obvious in males.

http://www.pnas.org/content/104/49/19351.full.pdf

Risk of neural tube defect is 34% lower in highest quartile of methionine intake

Women were categorized according to quartiles of daily methionine intake, based on the control mothers' distribution, and the risk for an neural tube defect-affected pregnancy was calculated using the lowest quartile of intake as the referent. RESULTS: With adjustment for income, body mass index, hyperinsulinemia, and diarrhea, the odds ratios for increasing quartile of methionine intake were: 0.95, 0.92, and 0.66. Some evidence of interaction between dietary methionine and serum vitamin B12 was noted, particularly at higher levels of both components. CONCLUSIONS: This study was limited by a small sample size but examined this association in an exclusively Hispanic population. Results were suggestive of a potential protective effect for neural tube defects with increasing maternal dietary methionine intake.

http://www.ncbi.nlm.nih.gov/pubmed/20589914

Methionine Information

As an essential amino acid, methionine is not synthesized in humans. High levels of methionine can be found in sesame seeds, Brazil nuts, fish, meats and some other plant seeds; methionine is also found in cereal grains. Most fruits and vegetables contain very little of it. Most legumes are also low in methionine.

http://en.wikipedia.org/wiki/Methionine