When it comes to sunburn and heat rash, prevention is definitely worth the effort. Use your favorite sunscreen if you have one.

Easing the pain after the damage is done is far more difficult — though we have a simple remedy that may help. In fact, you may be able to protect your skin from the inside out.

Scientists have found a number of dietary components that provide protection from ultraviolet injury if they are consumed regularly for an extended period of time. One of these is lycopene, which is the red pigment in tomatoes.

Researchers at the University of Manchester studied 20 fair-skinned British women. At the beginning of the study, each woman was exposed to a measured amount of ultraviolet light to find out how much it took to cause her skin to redden.

Then the women were assigned to eat either tomato paste in olive oil or plain olive oil every day for the next three months.

At the end of the study, the ultraviolet exposure test was repeated. The women who had been eating the tomato paste tolerated significantly more ultraviolet light without developing a burn (British Journal of Dermatology, Jan., 2011).

Other studies have shown that taking aspirin or vitamin C in combination with vitamin E can offer mild protection against sunburn (Photochemistry and Photobiology, Oct. 2001; Journal of the American Academy of Dermatology, Jan. 1998).

One study showed that taking vitamins E and C together reduced the amount of DNA damage that ultraviolet light did to skin cells (Journal of Investigative Dermatology, Feb. 2005).

Fish oil with EPA also seems to offer promise for protection (Carcinogenesis, May 2003). Researchers have had fairly good results with creams and lotions containing antioxidant vitamins or aspirin, but making such products at home is not practical.

“Instead of sunscreen, I take megadoses of vitamin C to protect myself,” said one reader. “This has worked for more than 20 years against sunburn. Of course, I don’t tan or freckle either. I take 3 grams of C each day, and once every year or two I might get a little pink on the most sensitive areas (nose, neck, and shoulders); otherwise, the vitamin C protects me against the radiation of the sun.”

One more possibility: Chocolate! In one study, women were randomly assigned to drink either high-flavanol or low-flavanol cocoa for three months.

Response to ultraviolet exposure was measured at the beginning and end of the trial. Skin reddening dropped 25 percent for women on high-flavanol cocoa (Journal of Nutrition, June 2006).

If you were unsuccessful in protecting your skin from the sun you may have to deal with the consequences. Some people develop a heat rash after sun exposure, especially at the beginning of the season.

Doctors have a name for this condition: polymorphous light eruption, or PMLE. It can be itchy and uncomfortable.

One reader wrote, “I often get a very itchy sun rash when I first go on holidays. Listerine calms it down so I can sleep and soon clears it. It also soothed an allergic reaction after a massage.”

We don’t know what ingredient in Listerine might be helpful for PMLE, but this old-fashioned amber mouthwash can also be used to ease the discomfort of a sunburn.

“For 25 years I have been using Listerine full strength in a spray bottle for sunburn,” another reader told us. “An old fisherman told me about it when I got a severe sunburn from sitting in a boat on a lake and got burned so bad that I looked like a lobster.

“The people I tell say this remedy works for them too. It stops the pain instantly. I keep it in my travel bag, in a zipper-top plastic bag to avoid spilling.

“I don’t like Listerine as a mouthwash but it’s great for sunburns. You don’t have to touch the skin and hurt yourself even more while you’re applying it.”