Alimentos fotoprotectores

Protecting your skin from the inside out

(CNN) — As cloudy skies start to turn sunnier, you might be checking your stash of sunscreen. But you may also want to see what's in your kitchen, as some foods can help keep your skin youthful and healthy.

"There are definitely foods that we eat that can boost our ability to protect our skin from the sun," said Dr. Patricia Farris, a dermatologist and fellow of the American Academy of Dermatology.

In terms of protecting yourself from sun damage, sun protection is the most important, like wearing a broad-spectrum sunscreen with an SPF of at least 30, along with sunglasses and hats, "but I would put diet right behind that -- and that's because there are so many components that you can consume from foods that have all these different protective effects," said Dr. Rajani Katta, author of "Glow: The Dermatologist's Guide to a Whole Foods Younger Skin Diet."

Even if you're not sunbathing at the beach, you might have incidental sun exposure as you go about your day, "and so making sure that there are high levels of nutrients in your skin is really going to help limit that sun damage," Katta added.

Antioxidants: edible sunscreens

There are several ways in which foods can affect your skin, protecting you against wrinkles, sunburn and skin cancer. But most of the mechanisms relate to antioxidants, antiaging compounds in foods that fight skin damage in different ways. 

For example, carotenoids are antioxidants that give pigment to orange and red fruits and vegetables and go by names such as lycopene, lutein and beta carotene. Carotenoids, along with polyphenols like EGCG in green tea, resveratrol in red grapes and ellagic acid in berries, offer natural sun protection.

Carotenoids and polyphenols accumulate in skin and absorb sunlight of various wavelengths, according to Farris. But the skin benefits of these natural compounds are primarily due to their antioxidant activity. Along with antioxidants like vitamin C and vitamin E, they protect against free radical damage to cells that's generated from the sun's UV rays, which can cause skin aging. 

For example, free radicals cause damage to proteins including collagen and elastin, which can lead to fine lines, wrinkles, sagging, loss of elasticity and brown spots, according to Katta. Free radicals can also damage lipids in cell membranes, which could lead to sagging as well as rough, dry skin. 

When antioxidants stop free radicals in their tracks, they also prevent DNA damage, thereby decreasing mutations and reducing the risk of skin cancer, Katta explained. 

And then there are antioxidants' anti-inflammatory effects, which protect against sunburn. For example, carotenoids, polyphenols, vitamins C and E and omega-3 fatty acids deliver anti-inflammatory benefits to skin, which helps to decrease the development of sunburn and may decrease the risk for skin cancer, Farris said. 

Supplements as sunscreen?

Though antioxidants from foods confer sun protection to skin, consuming them in supplement form poses risk. Oxidation is a finely balanced process, which means at high levels, antioxidants could morph into "pro-oxidants" and could create more damage, experts say.

Complicating the issue is that different supplements come with different safety profiles. For example, Heliocare is a fern extract with antioxidant activity and has been well-researched, according to Farris. "There are a lot of really good studies that show it reduces sunburn, oxidative stress and DNA damage." It may be beneficial for people at high risk for skin cancer or simply for a tennis player who wants some extra photoprotection, Farris explained.

But a study from France found an increased incidence of melanoma in women who took an antioxidant supplement. "These results were totally unexpected, and the increased risk of skin cancer disappeared after the antioxidant supplement was discontinued in a five-year followup study," Farris said. "So it appears that we still have a lot more to learn about the risks and benefits of antioxidant supplements."

Katta added, "whole foods contain multiple phytonutrients in one package ... and you can also be sure you're not getting too much. It's the easiest way to get the right dose of them."

Edible sunscreens: a shopping list 

For younger-looking skin, your diet should include plenty of antioxidant-rich foods to help decrease sunburn and neutralize free radicals that lead to skin aging and the potential for skin cancer. "Antioxidants in our skin are constantly being used up throughout the day, so it's really important that you constantly replenish that supply of antioxidants through your diet," Katta said.

In addition to providing antioxidant protection, fruits and vegetables boast fiber, which feed bacteria in your gut, making your skin's barrier less prone to irritation and less likely to lose moisture, Katta explained.

Tomatoes

Tomatoes are an excellent source of lycopene, an antioxidant pigment that may play a role in protecting against sunburn.

In one study, sunburn formation was significantly lower among those who consumed a small amount of tomato paste daily for 10 weeks. 

"If you consume about three tablespoons of tomato paste every single day for 10 weeks, at the end of that 10 weeks, you can see that your skin does not manifest the same level of sun damage," Katta said. 

While fresh tomatoes are also beneficial, lycopene is actually better absorbed when tomatoes are processed, especially with olive oil. Other lycopene-rich foods include pink grapefruit and watermelon.

Sweet potatoes and spinach

Sweet potatoes and spinach are rich in beta carotene, another carotenoid that helps decrease redness in skin when it is exposed to UV light. Spinach is also loaded with lutein, another skin-protective carotenoid. 

Other carotenoid-rich foods include carrots, mangoes, apricots, cantaloupe and kale.

Berries, grapes and pomegranate

These fruits offer sun-protective polyphenols: Raspberries, strawberries and pomegranate deliver ellagic acid, while red grapes are rich in resveratrol.

Oranges, grapefruit and kiwi 

Oranges, grapefruit and kiwi are loaded with vitamin C, which protects against free radical damage from the sun that can cause skin aging. In one study, higher intakes of vitamin C were associated with fewer wrinkles and less dryness.

Broccoli is also a source of vitamin C as well as the sun-protective compound sulforaphane.

Fatty fish

A diet rich in omega-3s from fish oil can help make sunburn less severe and may help prevent the development of skin cancer, according to research. Salmon, sardines, herring and trout are all excellent sources of omega-3s. 

"When I think about omega-3s, I think about them for their anti-inflammatory properties," Katta said. "It's important to have lots of omega-3 fatty acids in your diet."

Flaxseeds and walnuts 

These plant-based omega-3s are also important for skin health. They prevent moisture loss from cells, which keeps skin supple, and they are a source of the skin protective antioxidant vitamin E.

Sipping your sunscreen

In addition to small diet changes, what you choose to sip may shield your skin from the sun. 

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Drinking coffee may help lower the risk of malignant melanoma. In one study, four cups of coffee was associated with a 20% decreased risk of the disease.

And green tea contains beneficial polyphenols called catechins, which may help protect skin from sun damage and skin cancer, according to preliminary research. The studies on green tea are "very promising," according to Katta. 

Lisa Drayer is a nutritionist, an author and a CNN health and nutrition contributor.