Value of Nutrition-Based Therapies for Hair Growth, Color, and Quality

Abstract

Since an important commercial interest lies in the nutritional value of various vitamin and amino acid supplements, an important question that arises is whether increasing the content of an already adequate diet with specific amino acids, vitamins, and/or trace elements may further promote hair growth and pigmentation. Pharmacy aisles and Internet drugstores are full of nutritional supplements promising full, thick, luscious hair for prices that range from suspiciously cheap to dishearteningly exorbitant. It would appear that unless hair loss is due to a specific nutritional deficiency, there is only so much that nutritional therapies can do to enhance hair growth and quality. However, there are internal and external factors, such as aging and environmental stressors, that influence hair health to such a degree that nutritional therapy may boost hair that is suffering from these problems. Protein is the main component of hair with the primary component of the hair fiber being keratin that is made from amino acids. The most abundant of these is cysteine which gives the hair fiber much of its strength through the linking of the sulfur in cysteine molecules of adjacent keratin proteins together in disulfide bonds. Meanwhile, the hair follicle exhibits a high rate of metabolism. As a group, B complex vitamins are important for metabolic functions and therefore required to utilize other nutrients like carbohydrates and amino acids: biotin (vitamin H), calcium pantothenate (B5), niacinamide (B3), folic acid, and vitamins B6 (pyridoxal phosphate) and B12 (cobalamin). Further insights into the role of oxidative stress could open additional strategies for interventions into age-dependent hair and pigmentation loss. Specifically, the body possesses endogenous defense mechanisms, such as antioxidative enzymes (superoxide dismutase, catalase, glutathione peroxidase) and nonenzymatic antioxidative molecules (vitamins E and C, glutathione, ubiquinone), protecting it from free radicals. With age, the production of free radicals increases, while the endogenous defense mechanisms decrease. This imbalance leads to the progressive damage of cellular structures, ultimately resulting in the aging phenotype.