Sunlight and Diet

Your Diet, and Exposure to the Sun

When it comes to sun exposure, research shows that what you eat may matter more than you think.

Diets that are high in protein, animal fats, junk foods, soft drinks, vegetable oils, hydrogenated oils, animal and vegetable shortenings, and dairy products are associated with an increased risk of skin cancer.

Unhealthy oils are not just in food. You can also find them in skin care products such as suntan oils and skin lotions. Unhealthy oils in skin care products can also damage your skin and put you at risk.

The ultraviolet rays of the sun react with the fats in your body, forming free radicals. They damage your cells and can lead to cancer. Sunlight may play a role but the real culprit is a diet high in fat and low in antioxidants and nutrients.

If you eat a diet high in fruits, vegetables, and whole grains, you will be getting lots of nutrients, antioxidants, and other plant substances that will help prevent the formation of free radicals. This has a protective effect. Fresh, plant foods are very important in helping your body be able to handle exposure to sunlight. Antioxidants protect your skin from burning too quickly. They also prevent premature aging.

The following information is taken from an article for the American Institute for Cancer Research by Karen Coolins, M.S., R.D., C.D.N.:

A study in the American Journal of Clinical Nutrition noted that carotenoid supplements reduced skin reddening in response to ultraviolet light. The supplements raised carotenoid levels in the skin. A later report in the Journal of Nutrition said people who had higher skin carotenoid levels without supplements suffered less reddening skin damage from ultraviolet light.

These studies involved fair-skinned people with a tendency to develop sunburn. It is not clear if the results would be the same for people with darker skin. The reduced skin damage linked to carotenoids is clearly related to increased carotenoid pigment in the skin. In fact, subjects in the above study who used supplement-level doses developed a slight yellowing of the skin, especially on the face and palms.

Another study, in the Journal of Nutrition, found that tomato paste, which is high in the carotenoid lycopene, also seems to offer some protection from sunlight's damage. After ten weeks, people who ate the equivalent of half a small can of tomato paste each day reduced their usual reddening from ultraviolet light by 35 percent. This study did not evaluate whether skin pigment levels changed, or what mechanisms were involved.

Other research has taken a broader look at how diet might protect skin against sun damage. Many phytochemicals - substances that naturally occur in fruits, vegetables, grains and other plant foods - are antioxidants. A study in the Journal of the American College of Nutrition showed that skin wrinkling on sun-exposed body parts in elderly people was lowest among those who ate the most vegetables, beans and olive oil. Prunes, apples and tea (also high in antioxidant phytochemicals) were also related to reduced wrinkling.

Sunlight exposure reportedly causes 80 to 90 percent of skin cancer, which is why experts recommend sunscreens with a Sun Protection Factor (SPF) of 15 as a minimum. Researchers in the carotenoid and lycopene studies estimate an effect equal to only a 2 or 3 SPF. Furthermore, a panel of experts found that sunscreens probably reduce the risk of some skin cancers but should be only one part of an overall strategy that includes limited sun exposure. Studies suggest that, if using sunscreens leads people to spend more time in the sun, the risk of a very serious skin cancer called melanoma may actually increase.

The American Institute for Cancer Research (AICR) recommends a mostly plant-based diet with five to ten daily servings of a variety of fruits and vegetables to lower overall cancer risk. If such a diet helps protect against sunburn, wrinkling and skin cancer, consider it a bonus. Healthy eating, offering a daily SPF of 2 or 3, may reduce sun damage that occurs during brief periods out of doors.