Colomb L, Flament F, Wagle A, Agrawal D
L'Oréal Research and Innovation, 188, Rue Paul Hochart, 94550, Paris, France.
L'Oréal Research and Innovation, 7th Floor, Universal Majestic, Ghatkopar - Mankhurd Link Road, Chembur, Mumbai, - 400 071, India.
Int J Cosmet Sci. 2018 Feb;40(1):50-57. doi: 10.1111/ics.12431. Epub 2017 Nov 10.
India is a large country (a subcontinent) of about 3.3 million km that covers large ranges in latitude and longitude. The last Indian census counted about 1.21 billion of inhabitants of many origins, creating a vast human diversity and skin types, the variability of which having been previously established. The present study aimed at deepening this knowledge through a set of biophysical measurements to describe, along the skin ageing process, the specificities of various Indian subjects living in different geographical locations.
A total of 1204 women, aged 18-84 years, of all socio-economic status, were recruited in four Indian cities (Mumbai, Kolkata, Chennai and Delhi). Measurements of face skin colour properties, elastic properties, sebum production, skin pores and microrelief roughness were performed.
With regard skin colour, this study indicates, with age, a darkening of very low amplitude that leads to an increased skin colour heterogeneity. In all subjects, at all ages, the ocular region (dark circles) presents a much darker pigmentation than the cheeks, creating a contrast that appears constant at all ages. In addition to an increased skin colour heterogeneity, a progressive alteration of the skin surface relief, increased sizes of skin pores, a loss of skin elasticity and a drop in sebum production, post-menopause, are observed.
This study confirms, in Indian women, some skin ageing measurements found on women from other ethnic groups (i.e. sebum, firmness, wrinkles and pores size) and also identifies some Indian specificities: a high and constant contrast between the ocular region and the cheek colour, associated to a very slow darkening effect along the lifespan.
印度是一个幅员辽阔的国家（一个次大陆），面积约330万平方公里，跨越很大的纬度和经度范围。印度上一次人口普查统计了约12.1亿来自多种族裔的居民，形成了巨大的人类多样性和皮肤类型差异，此前已证实其具有变异性。本研究旨在通过一系列生物物理测量来深化这方面的认识，以描述不同地理位置的印度受试者在皮肤衰老过程中的特异性。
在印度的四个城市（孟买、加尔各答、钦奈和德里）招募了1204名年龄在18至84岁之间、社会经济地位各异的女性。对面部皮肤的颜色特性、弹性特性、皮脂分泌、毛孔和微观纹理粗糙度进行了测量。
关于皮肤颜色，本研究表明，随着年龄增长，皮肤颜色会有非常微小的加深，导致皮肤颜色异质性增加。在所有受试者的所有年龄段，眼部区域（黑眼圈）的色素沉着都比脸颊深得多，在各个年龄段这种对比似乎都是恒定的。除了皮肤颜色异质性增加外，还观察到皮肤表面纹理逐渐改变、毛孔变大、皮肤弹性丧失以及绝经后皮脂分泌减少。
本研究证实了印度女性身上存在一些在其他种族女性中也发现的皮肤衰老特征（即皮脂、紧致度、皱纹和毛孔大小），同时也确定了一些印度特有的情况：眼部区域和脸颊颜色之间存在高且恒定的对比，以及一生中皮肤颜色加深的速度非常缓慢。
