Nutraceuticals column Cysteine : The FunKe Nutraceutical

Abstract

The “conditionally essential” sulphur-amino acid cysteine plays a critical role in antioxidant defenses and has extensive involvement in many biologic pathways. Lacking in many diets, levels of cysteine and its metabolites decrease dramatically as we age [1] and dietary deficiencies may lead to chronic inflammation, contributing to the development and progression of several diseases caused by the breakdown of antioxidant mechanisms [2,3]. An important antioxidant is glutathione (GSH), a tripeptide of glutamate, cysteine, and glycine, the synthesis of which is primarily regulated by availability of cysteine and activity of the enzyme, glutamate cysteine ligase. Increasing, GSH synthesis may be therapeutic for aging, liver disease, cystic fibrosis, sickle cell anaemia, human immunodeficiency virus/AIDS, cancer, stroke, and diabetes [4]. Most recently, it has been demonstrated in young adult volunteers on a cysteine-free diet, that sulphur repletion rapidly improves fasting plasma cysteine/cystine redox potential, a potentially important biomarker for cardiovascular disease [5].