Whilst sulphur is important for the formation of the hair fibre, there are many other roles for this chemical element that contribute to overall hair health:
The manufacture of proteins – Proteins are considered as biological workhorses of all cells. First they exist as unfolded polypeptides or amino acid chains derived from mRNA. Proper protein folding is essential for the correct function of all proteins. Sulphur is able to exert a protection action over potential protein misfolding by increasing hydration around a polypeptide inducing proper packing of the protein and stabilisation of the proteins conformation. The high keratin content of the hair makes correct protein folding essential for the integrity of the hair fibre.
Increased blood flow – Sulphur moieties stimulate prostacyclin synthesis which increases in the size of blood vessels. This is known as vasodilation and increases blood flow all over the body when sulphur is consumed or supplemented or in an individual area when applied topically. Increasing blood flow increase the exchange of nutrients and waste from cells. Cells of the hair follicle and hair fibre divide faster than most cells in the body, they are nutritionally expensive and require a constant and high level of biological metabolites to run.
Maintains the integrity of the connective tissue housing the hair follicle – Sulphur is needed for the sulphation of proteoglycans. Proteoglycans intersect the cell membrane and stabilise the hair follicle and assisting in transmembrane cell signalling and binding of growth factors. Sulphur also helps maintain collagen levels, providing anchorage for the base of the hair follicle.
Reduces cell damage and inflammation – Sulphur reduces mRNA levels of inflammatory proteins such as IL-6 and IL-1A leading to reduced inflammation. Sulphur also increase the cells ability to get rid of dysfunctional cellular components via a process called autophagy. Correct autophagy ensures cell survival when nutrients are low via the recycling of amino acids and fatty acids. Sulphur helps hair follicles maintain immune privilege, the loss of immune privilege is linked to hair loss conditions such as alopecia areata.
Can increase availability of sulphur containing amino acids – Elemental sulphur can be incorporated into polypeptides to form cysteine and methionine, the main building blocks of the hair fibre. Low availability of sulphur containing amino acids are linked to sudden hair shedding that can continue over a period of weeks (telogen effluvium).
Supports detoxification in the liver – The liver uses sulphur containing enzymes (sulphotransferases) to increase the water solubility of proteins, steroid hormones, lipids and other compounds to reduce biological activity and aid in excretion via the kidney or bile. Proper liver function contributes to the normal growth of hair and the appropriate balancing of hormones such as estrogen and testosterone.
Essential for cell function – Taurine can be derived from sulphur to regulate intracellular levels of calcium, improve energy production and maintain cell integrity. Sulphur is also responsible for ion exchange in the cell due to its oxygen sensing capabilities and cell membrane permeability.