Cysteine facts
- Cysteine is a conditionally essential amino acid
- Cysteine functions as a building block of protein in the body
- Cysteine is created from methionine
- Cysteine is a sulphur-containing amino acid
- Cysteine is closely related to cystine
- Nails, skin and hair all contain cysteine
- Cysteine is in the form of N-acetyl cysteine (NAC)
While cysteine is not an essential amino acid most of the time (essential amino acids are required in the diet as the body cannot manufacture them), there are certain special circumstances which makes it conditionally essential; this means cysteine becomes an essential amino acid under special conditions, especially when intake of the essential amino acid methionine is very low.
Cysteine, just like all the other amino acids, is one of the building blocks of all proteins in the body, which not only include muscles, but also all the other proteins required for normal function of the body.
Cysteine is a sulphur-containing amino acid, in a form that inactivates free radicals and protects the cells from oxidative damage which can lead to heart disease, cancer and premature ageing. Cysteine also provides protection against the oxidative damage of pollutants such as cigarette smoke, pollution, environmental toxins and alcohol.
Cystine consists of two cysteine molecules joined together. Cysteine can be unstable, but can be converted into cystine by the body when required (and vice versa).
Cysteine is one of the sulphur-containing amino acids (the others are methionine and taurine). The sulphur in cysteine is useful in maintaining healthy skin tone, strong nails and beautiful hair.
The form of cysteine that is most easily absorbed and used by the body is N-acetyl-cysteine (NAC) and this is the same form which is usually found in supplements too.
