Faces with a rosy glow, whether the look is achieved by nature or skillfully applied make-up, appear healthy and attractive. Researchers in Scotland found that rosy, healthy-looking skin was easily achieved by eating more fruits and vegetables daily for six weeks. The rosy glow was most likely due to carotenoids, the pigmented antioxidants, found in fruits and vegetables.
Carotenoids and skin
The yellow and red colors of fruits and vegetables are due to carotenoids. Carotenoids are a large group of antioxidants that are found in vegetables, such as tomatoes, peppers, and carrots, and in fruits, such as plums, peaches, and mangoes. After eating carotenoid-rich food, the carotenoids are absorbed by the intestine and eventually become distributed to all skin layers, contributing to the skin's pigmentation. As strong antioxidants, carotenoids have many health effects. Antioxidants fight the harmful oxidative stress produced by the body's metabolism, immune and inflammatory processes. Skin is especially susceptible to oxidative stress because of exposure to UV radiation, smoking, ozone and pollutants in the atmosphere.
Researchers measured the change in pigmentation in 35 students (the majority were women) over a six week period after increasing their intake of fruits and vegetables. Anyone who tanned or used make-up was excluded. Using spectrophotometric methods, changes in skin color and reflectiveness were measured initially, at three weeks, and at six weeks. In a psychological experiment, other students were asked to rate the health and attractiveness of facial images with increasing color changes equivalent to changes caused by eating fruits and vegetables.
Time frame for rosy glow
Carotenoids are fat-soluble substances and when extracted from the intestines will take up residence in all layers of the skin. The researchers found that it takes some time before extra servings of fruit and vegetables impact the color of the skin. They noticed significant color changes at six weeks, but not at three weeks.
How many servings of fruit or vegetables are effective?
Laboratory methods could detect color changes even with only one extra daily serving of fruits or vegetables, but to achieve the perception by others that the skin looked healthy and attractive required an increase of two to three daily servings of fruits and vegetables.
What constitutes a serving of fruits and vegetables?
The U.S. Department of Agriculture defines a serving of fruits and vegetables as either:
- · One medium piece of fruit such as an apple
- · One half cup of berries or diced fruit
- · One quarter cup of dried fruit
- · Six ounces of juice
- · One half cup of raw or cooked vegetables
- · One cup of leafy vegetables.
Serving sizes are only approximate measures.
Considerations and precautions
All participants in the study were light-skinned. Carotenoid color changes may differ in darker-skinned people. Some carotenoids, such as beta-carotene, also help to generate vitamin A in the body. Vitamin A is important for eye and skin health, but in very high concentrations has detrimental effects. My aunt was fond of telling the story of a man, who went on a "carrot diet" and how his skin turned dark yellow and he became very sick.
Whitehead, R.D. et al. You are what you eat: Within-subject increases in fruit and vegetable consumption confer beneficial skin-color changes. PLoS One (2012) 10.1371/journal.pone.0032988