Fruits and vegetables are an important dietary source of nutrients, including antioxidants that help stave off cellular damage due to oxidative stress and could protect us against a variety of age-related diseases, cardiovascular disease, diabetes and perhaps some forms of cancer. Nutrition experts advise us to eat at least five servings of fruits and vegetables each day, but many of us don’t. Furthermore, the health benefits of a vegetable-rich diet aren’t necessarily enough motivation for us to change our diets, even though we know we should. A recent finding reported in PLoS ONE gives us an extra reason to incorporate more fruits and vegetables into our menus: We might just improve our skin color and look more attractive.
Fruits and vegetables contain carotenoids, which are fat-soluble pigments that accumulate in the dermis and epidermis to give skin yellow and red tones. In a recent PLoS ONE report (1), scientists at the University of St. Andrews in Scotland hypothesized that increased consumption of fruits and vegetables, and as a result increased carotenoid consumption, causes noticeable changes in skin color. These researchers tracked the diet of 35 Caucasian college students and measured skin color and reflectance using a spectrophotometer over the course of 6 weeks. They found that as the students’ intake of fruits and vegetables increased, their skin took on more red and yellow tones and had decreased light reflectance at 400–540nm. The change in reflectance varied with the wavelength of light, with the greatest changes observed at the absorption maxima for the carotenoids lycopene and ß-carotene. Reflectance did not change significantly at the absorption maximum of melanin, a pigment that increases as skin is exposed to ultraviolet light, ruling out the possibility that suntans caused these changes.
Knowing that red and yellow skin tones are associated with good health and attractiveness in humans, the authors decided to investigate whether these changes in skin color and reflectance made the students more attractive to others. The authors generated four images of Caucasian faces (two males and two females), then created two color masks: one that simulated the color changes observed for high fruit and vegetable consumers and the other for low fruit and vegetable consumers. Test subjects viewed an unmanipulated image along side the same image with one of the color masks applied, then were asked to compare the attractiveness of each image in the pair. Test subjects routinely chose as more attractive the faces with more red and yellow tones.
Changes in skin yellowness are associated with good health regardless of ethnicity, so although this particular study examined the change in skin color and reflectance in Caucasian students, there is reason to believe that the benefits of eating more fruits and vegetables apply to other ethnic groups as well.
Fortunately, students did not have to change their diets dramatically to reap these benefits: Fewer than four extra servings of fruits and vegetables per day made a noticeable difference. However, the effects were not immediate—in this study, skin color and reflectance values did not change significantly from initial measurements until the sixth week.
The authors point out that an increase in carotenoids might not be the only explanation for this effect. Polyphenols, which are found in abundance in fruit and vegetables, appear to increase arterial elasticity and endothelium health and could increase blood perfusion in the skin, further adding to the glow of healthy skin.
So, after learning about this new research, we all have one more reason to increase the number of fruit and vegetable servings per day. The question becomes: Will we?
1. Whitehead, R.D. et al. (2012). You are what you eat: Within-subject increases in fruit and vegetable consumption confer beneficial skin-color changes. PloS ONE, 7, e32988. PMID: 22412966