Methionine Restriction — Diets
Targeted reduction of the amino acid methionine to activate longevity pathways and mimic caloric restriction benefits.
Overview
Methionine restriction (MR) involves reducing intake of the essential amino acid methionine by 80% or more. In animal models, MR extends lifespan by 30-45%, reduces adiposity, improves insulin sensitivity, and increases metabolic rate. The mechanism parallels caloric restriction, activating FGF21, improving hydrogen sulfide signaling, and reducing oxidative stress, but without reducing total calories. Human translational studies are in early stages, but epidemiological data links high methionine diets to cancer and cardiovascular disease. Practically, MR is achieved through a predominantly plant-based diet (plants are low in methionine) or through modified food formulations. Vegan diets naturally provide 50-70% less methionine than omnivore diets.
Indications
- Longevity pathway activation
- Cancer risk reduction (preclinical)
- Metabolic health improvement
- Oxidative stress reduction
Mechanism of Action
Methionine restriction activates the integrated stress response (ISR) via GCN2 kinase, inducing FGF21 which improves insulin sensitivity and energy expenditure
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Methionine Restriction | 1.0-2.0 mg methionine/kg/day (vs. typical 15-25 mg/kg/day) | Daily | Primarily plant-based diet; limit high-methionine foods (meat, fish, eggs, dairy) |
Safety & Contraindications
- Primarily supported by animal data; human evidence is limited
- Extreme methionine restriction may impair methylation and protein synthesis
- Not recommended for growing children, pregnant women, or sarcopenic elderly
- Must ensure adequate total protein and other essential amino acid intake
- Glycine supplementation may provide some benefits of MR without restriction