Why some women look young for their age

Abstract

The desire of many to look young for their age has led to the establishment of a large cosmetics industry. However, the features of appearance that primarily determine how old women look for their age and whether genetic or environmental factors predominately influence such features are largely unknown. We studied the facial appearance of 102 pairs of female Danish twins aged 59 to 81 as well as 162 British females aged 45 to 75. Skin wrinkling, hair graying and lip height were significantly and independently associated with how old the women looked for their age. The appearance of facial sun-damage was also found to be significantly correlated to how old women look for their age and was primarily due to its commonality with the appearance of skin wrinkles. There was also considerable variation in the perceived age data that was unaccounted for. Composite facial images created from women who looked young or old for their age indicated that the structure of subcutaneous tissue was partly responsible. Heritability analyses of the appearance features revealed that perceived age, pigmented age spots, skin wrinkles and the appearance of sun-damage were influenced more or less equally by genetic and environmental factors. Hair graying, recession of hair from the forehead and lip height were influenced mainly by genetic factors whereas environmental factors influenced hair thinning. These findings indicate that women who look young for their age have large lips, avoid sun-exposure and possess genetic factors that protect against the development of gray hair and skin wrinkles. The findings also demonstrate that perceived age is a better biomarker of skin, hair and facial aging than chronological age.

Figure 1. Composite images representing the effects of environmental factors on variation in perceived age between monozygotic twin sisters (upper images) and the effects of environmental and genetic factors on variation in perceived age between dizygotic twin sisters (lower images).

a, Younger looking and b, older looking monozygotic twin sister composites (mean perceived age 64 [57–70] and 70 [60–85] respectively). c, Younger looking and d, older looking dizygotic twin sister composites (mean perceived age 64 [59–74] and 76 [69–84]). The older looking twin sister composites demonstrate signs of increased skin wrinkling, increased nasolabial fold shadowing (running from the lateral edge of the nose to the outer edge of the mouth) and, particularly for the non-identical twin comparison, a grayer skin color, a thinner face and reduced lip fullness. Each composite image was derived from 14 twin images and the chronological age was 67 [60–76] and 69 [61–79] for the monozygotic and dizygotic composites respectively; square brackets denote age ranges.

Figure 2. Composite images representing the average differences between 50 and 70 year olds (upper images) and 70 year old young and old looking subjects (lower images) in the British population.

Composite images of a, 50 year olds (mean chronological age 50 [48–52]) and b, 70 year olds (mean chronological age 70 [68–72]). c, Young looking 70 year olds (mean perceived age 62 [57–68]) and d, old looking 70 year olds (mean perceived age 73 [67–79]) composite images. Differences in skin wrinkling and the nasolabial fold (upper and lower images) and lip fullness (lower image) are similar to those in the twin composites (Figure 1). The upper images were each derived from 18 female images and the lower images from 17. The mean chronological age was 71 [67–75] and 70 [66–74] for the young and old looking 70 year old composites respectively; square brackets denote age ranges.

Figure 3. Example of the most discordant monozygotic twin pair (68 years of age, perceived facial age a 63 years and b 68 years) and dizygotic twin pair (71 years of age, perceived facial age c 71 years and d 82 years) for skin wrinkling grading.

These images illustrate the greater differences in skin wrinkling that was found between dizygotic twins compared to monozygotic twins. Images are derived from the blue light channel of the photographs.