Department of Dermatology, University of California, Irvine, Irvine, CA, USA.
Int J Dermatol. 2023 Mar;62(3):404-415. doi: 10.1111/ijd.16109. Epub 2022 Feb 26.
Hair lipid composition varies by ethnic hair type and by hair layer. Lipids in the cuticle, cortex, and medulla of the hair shaft provide a protective barrier to environmental and chemical damage, prevent hair breakage and desorption, and affect the elastic and tensile properties of hair. The aim of this systematic review is to provide an overview of the lipid composition and ethnic differences of human hair, effects of external damage on lipid content and properties, and changes in hair lipid composition associated with disease states. PubMed/MEDLINE was searched up to March 2021 according to PRISMA guidelines for articles discussing the lipid content of human hair and effects of physical, chemical, or environmental damage, and disease. Fifty-nine articles investigating the lipid content of hair were included for review. Lipids affect fluid permeability, hydration, strength, and texture of ethnic hair fibers. Lipid loss is accelerated by hair-damaging treatments such as bleach, dye, perm, straightening, and surfactant use, and sun and aging processes, leading to dehydrated, breakable, disordered, and dull hair. Diseases including acne, alopecia, and breast, gastric, prostate, lung, and rectal cancers display elevated hair lipid levels. Lipids are vital in protection against damage and maintenance of healthy hair. Further studies are needed to investigate the effects of lipids on the structural properties of ethnic hair, and changes in hair lipid composition with various dermatologic and systemic diseases.
头发的脂质组成因种族和头发类型以及头发层而异。毛干的表皮层、皮质层和髓质层中的脂质为头发提供了环境和化学损伤的保护屏障，防止头发断裂和脱落，并影响头发的弹性和拉伸性能。本系统综述的目的是概述人类头发的脂质组成和种族差异、外部损伤对脂质含量和性质的影响，以及与疾病状态相关的头发脂质组成的变化。根据 PRISMA 指南，检索了截至 2021 年 3 月的 PubMed/MEDLINE 中讨论人类头发脂质含量和物理、化学或环境损伤以及疾病影响的文章。共纳入了 59 篇研究头发脂质含量的文章进行综述。脂质影响着纤维的透液性、保湿性、强度和质地。头发损伤处理，如漂白、染色、烫发、拉直和表面活性剂的使用以及日晒和老化过程，会加速脂质流失，导致头发干燥、脆弱、紊乱和无光泽。包括痤疮、脱发以及乳腺癌、胃癌、前列腺癌、肺癌和直肠癌在内的疾病，都显示出毛发脂质水平升高。脂质对于保护头发免受损伤和维持健康头发至关重要。需要进一步研究脂质对不同种族头发结构特性的影响，以及各种皮肤和系统性疾病中头发脂质组成的变化。
