What is methionine and how to avoid too much of it.

Methionine is an essential amino acid in humans and the precursor of other non-essential amino acids. Its antioxidant properties can help protect the body from damage caused by ionizing radiation. It may detoxify harmful substances in the body such as heavy metals and prevent liver damage from acetaminophen poisoning and help prevent fat deposits in our liver. 

Numerous studies have reported however, that excessive methionine intake can induce dyslipidemia (elevated cholesterol or fats (lipids) in the blood), oxidative stress, hepatic lipid accumulation, and cardiovascular disease (Chaturvedi et al., 2016; Navik et al., 2021). 

Consuming a methionine-restricted diet (MRD) has been found to induce reductions in body weight and liver fat deposition, enhance stress resistance, improve age-related diseases, and extending longevity (Gao et al., 2019; Longchamp et al., 2018; Ren et al., 2021).

Foods low in methioine include fruits, nuts, veggies, grains, and beans, whereas foods to avoid due to higher content of methionine and potential higher risk disease, include chicken, fish, milk, red meat, and eggs.