Nagase Shinobu, Kajiura Yoshio, Mamada Akira, Abe Hiroko, Shibuichi Satoshi, Satoh Naoki, Itou Takashi, Shinohara Yuya, Amemiya Yoshiyuki
Beauty Research Center, Kao Corporation, 2-1-3 Bunka, Sumida-ku, Tokyo 131-8501, Japan.
J Cosmet Sci. 2009 Nov-Dec;60(6):637-48.
To clarify hair changes by aging, the effect of age on hair properties was investigated from macro- to microscopic view points. Sensory hair luster tests were performed on 230 Japanese females from 10 to 70 years of age, revealing that hair luster decreases with age. The age dependence of the hair diameter and the ellipticity of the hair cross section could not explain luster reduction by aging. It has been determined that an irregular increase in fiber curvature occurs with age and is a cause of luster reduction with aging. A detailed structural analysis by synchrotron radiation microbeam X-ray diffraction revealed that the inhomogeneity in the lateral distribution of the hair microstructure increased with age and relates to the irregular increase in curvature. Such an increase in curvature is one of the important factors that leads to a poor alignment of hairs and luster reduction, and is related to the appearance of aging hair.
为了阐明衰老对头发的影响，从宏观到微观的角度研究了年龄对头发特性的作用。对230名年龄在10至70岁之间的日本女性进行了头发光泽感官测试，结果显示头发光泽随年龄增长而降低。头发直径和头发横截面椭圆率的年龄依赖性无法解释衰老导致的光泽度降低。已确定随着年龄增长，纤维曲率会不规则增加，这是衰老导致光泽度降低的一个原因。同步辐射微束X射线衍射的详细结构分析表明，头发微观结构横向分布的不均匀性随年龄增长而增加，并且与曲率的不规则增加有关。这种曲率增加是导致头发排列不佳和光泽度降低的重要因素之一，并且与衰老头发的外观有关。
