Methionine sulphoxide reductase is an enzyme involved in antioxidant defence, protein regulation and prevention of aging-associated diseases. Evidence has accumulated suggesting that methionine oxidation may play an important role in the development and progression of neurodegenerative diseases like Alzheimer’s and Parkinson’s diseases and heart disease.
By their action, the methionine sulphoxide reductase enzymes can regulate protein function, be involved in signal-transduction pathways and prevent cellular accumulation of faulty proteins.
The eventual product of the demethylation of methionine is homocysteine and its re-methylation is catalysed by the vitamin B6 (pyridoxine), vitamin B9 (folate) and vitamin B12 (cyanocobalamin) dependent enzyme, methionine sulphoxide reductase. Any interruption of the methylation cycle resulting from a deficiency of the B vitamins may have serious long-term risks. It can lead to the degeneration of the spinal cord and peripheral nerves. If left untreated, it will lead to ataxia, paralysis and ultimately death. High homocysteine levels can also lead to heart attacks and strokes.
NOTE: Strict vegans are at most risk as their diet is often lacking in vitamin B12. Excessive alcohol and certain medications also reduce the B vitamin levels in the body.
Foods that can support the methionine sulphoxide reductase enzymes
S-methyl-L-cysteine (SMLC) is a compound, found abundantly in allium vegetables, the richest source being Brussel sprouts. This compound has been shown to enhance the actions of the methionine sulphoxide reductase enzymes.
Natural sources of S-methyl-L-cysteine in alphabetical order
- Broccoli
- Brussel sprouts (highest source)
- Cabbage
- Cauliflower
- Garlic
- Kale
- Leeks
- Onions
- Rakkyo (a type of onion, also known as Chinese onion or Japanese scallion)
- Turnips
Natural foods rich in the B complex of vitamins are vital for methionine sulphoxide reductase actions. To find out the highest natural sources see>>
For more about the amino acid required to produce methionine sulphoxide reductase see>> Methionine
Related subjects
- A-Z of nutrients
- Dementia (Alzheimer’s disease)
- Heart disorders
- Nerve disorders
- Parkinson’s disease
- Strokes
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