Free internal lipids in hair from pre‐ and post‐menopausal women

Abstract

Little is known about changes in hair lipids during life and their effects on hair properties. Our objectives were to study for the first time the effects of the female menopause on hair lipids, the contribution of sebum, and hair quality using pre‐menopausal and post‐menopausal subjects with and without hormone replacement therapy. Extracted hair lipids were quantified by high performance thin layer chromatography, forehead sebum output measured by sebumeter and hair greasiness, shine, softness and smoothness evaluated by expert assessment. Pre‐menopausal free internal lipids contained free fatty acids, wax or cholesteryl esters, cholesterol, ceramides, triglycerides and squalene. The composition was distinct from scalp surface lipids collected at the same time and from hair follicles from facelift patients, with no wax or cholesteryl esters and squalene in follicles and no ceramides in the surface lipids. Wax or cholesteryl esters and squalene were decreased (P < 0.05) and cholesterol and ceramides increased (P < 0.05) in post‐menopausal hair. The changes for squalene, wax or cholesteryl esters and cholesterol were reduced when hormone replacement therapy was taken. Sebum output and hair greasiness, shine, softness and smoothness fell significantly (P < 0.05) after menopause. Hormone replacement therapy increased (P < 0.05) results after menopause. It is concluded that hair free internal lipids derive from both the hair follicle and sebum. Sebum output falls after menopause and contributes less to hair lipids. The hair condition also changes. Understanding hair changes during life should improve matching of hair products to consumer needs.

6‐O glucose linoleate supports in vitro human hair growth and lipid synthesis

“…Integral lipids of human hair follicle have been characterized by Wertz and Downing [7]. Free internal lipids in hair, although imperfectly characterized [8–10], were shown to originate from both the sebum and hair follicle itself [11], to be distinct from scalp surface lipids and to change with menopause [12]. Various lipids have been found as hair lipids, including hydrocarbons, squalene, wax esters, triglycerides, fatty acids, cholesterol, cholesterol sulphates, 18‐methyl‐eicosanoic acid (18‐MEA) and ceramides.…”