How a Healthy Diet Can Protect You from Skin Cancer
You got the pale-is-the-new-tan memo years ago and have the sun smarts to prove it. Skin cancer is the most common cancer in the United States, and women age 39 and under have a higher probability of developing its most serious form, melanoma, than they do any other invasive cancer except breast cancer. Yep; knew that. Slather on waterproof sunscreen before you exercise, sport floppy broad-brimmed hats at the beach, stay out of midday rays, and steer clear of tanning beds. Check; do all that. Still, despite your savvy and diligence, there's a new stealth skin saver you may be missing: your diet.
"The research is preliminary but promising," says Karen Collins, RD, clinical dietitian and nutrition adviser for the American Institute for Cancer Research in Washington, D.C. "In addition to limiting your sun exposure, eating certain foods may help reduce your risk."
Much of the recent research focuses on the sun-soaked Mediterranean. Despite their typically outdoor lifestyles, dwellers in this region are less likely to get melanomas than Americans, and some scientists believe that in addition to their olive skin tone, the disparity may be due to the two cultures' very different eating habits. The region's largely plant-based diet, brimming with vegetables and fruits as well as olive oil, fish, and fresh herbs, was found to cut melanoma risk by 50 percent in an Italian study published in the International Journal of Epidemiology.
Researchers point to the diet's antioxidants, substances thought to help protect against cellular damage caused by the sun's ultraviolet (UV) radiation, which is still the biggest risk factor for skin cancer, according to dermatologists. Here's how the process works: UV light damages skin cells, which then release oxygen molecules called free radicals. If free radicals damage your DNA, they can alter it, and skin cells may turn cancerous and replicate. The good news is that having a large amount of antioxidants in your skin and body may neutralize the free radicals and thus prevent or slow skin cancer growth. In fact, research has shown that people who drank a daily antioxidant-rich beverage had 50 percent fewer free radicals in their blood after two weeks than those who didn't drink the blend — and both groups were exposed to three to six steady hours of sun a day!
There's also a new, growing body of research looking into the "antiangiogenic" properties of foods. Sun damage to the skin causes the growth of new blood vessels, in a process called angiogenesis, that cancer cells hijack to feed themselves. "Antiangiogenesis substances in food can starve cancer cells, preventing them from growing and becoming dangerous," says William Li, MD, president and medical director of the Angiogenesis Foundation in Cambridge, Massachusetts. Certain foods — including omega-3 fatty acid-rich fish, which is plentiful in the Mediterranean diet — contain these antiangiogenic substances. Some antioxidant-rich foods show antiangiogenic activity, too, Dr. Li adds.
Chances are that you're already getting at least some cancer-fighting fare if you eat a healthy diet. Making a few small changes may help boost your protection further. "Food is the chemotherapy we all take three times a day," Dr. Li says. So in addition to keeping the sunblock at the ready this summer, stock your fridge and pantry with a new kind of SPF: skin-protective foods. Borrow these smart strategies from the Mediterranean style of eating to add a cancer-protective dose of antioxidants and antiangiogenic agents to your diet. Here are five easy ways to get SPF on your plate and in your cup.
5 Diet Must-Haves to Beat Skin Cancer
As you strive for the five or more daily servings of fruits and vegetables the American Cancer Society recommends, make sure there is plenty of dark green and orange in your mix. As part of your minimum 35 weekly portions, eat three servings of cruciferous vegetables, such as broccoli, cauliflower, and kale; another four to six of dark green leafy vegetables, like spinach, beet leaves, and collard greens; and seven of citrus fruits — all of which were found by the Italian study to be skin cancer protective when consumed in large amounts. "These foods contain powerful antioxidants, including polyphenols, carotenoids, and other bioactive substances, that may decrease the risk for melanoma," comments study author Cristina Fortes, PhD, researcher in the clinical epidemiology unit at the Istituto Dermopatico dell'Immacolata in Rome.
You don't have to give up juicy summer burgers; just enjoy some fish regularly to help keep your skin healthy. Thanks to the anti-inflammatory action of omega-3s, found mainly in shellfish and naturally fatty fish, eating at least a weekly serving of those foods may double your melanoma protection, Fortes's research found. Fortes adds that such a diet may also protect against nonmelanoma skin cancers, which are less deadly but more common. Australian researchers found that people who ate an average of one serving of omega-3 fatty acid-rich oily fish, like salmon, sardines, mackerel, and trout, every five days developed 28 percent fewer actinic keratoses — rough, scaly precancerous skin patches or growths that are caused by UV exposure and can turn into an early form of squamous cell carcinoma, according to a study published in 2009 in the American Journal of Clinical Nutrition.
Pass the Herbs
Adding a dash of herbs to your salad, soup, chicken, fish, or anything else you love to eat not only makes your food more flavorful but also helps fortify your skin. Herbs can pack an antioxidant wallop — one tablespoon can have as much as a piece of fruit — and may protect against melanoma, according to Fortes's research. Fresh sage, rosemary, parsley, and basil offer the greatest benefits. "This doesn't mean you have to use four herbs at once," Fortes clarifies. "Just use some type of fresh herb every day."
Steep Some Tea
Make your postbeach beverage of choice a refreshing homemade iced tea, which may help thwart the cascade of cellular damage set off by sun exposure. A lab study found that the polyphenol antioxidants in green and black teas inhibit the proteins necessary for skin cancer to develop. "They may also starve cancer development by limiting blood vessel growth around tumors," says study coauthor Zigang Dong, MD, executive director and section leader of the cellular and molecular biology lab at the Hormel Institute at the University of Minnesota in Austin. In Fortes's findings, drinking a daily cup of tea was linked to a lower incidence of melanoma. And Dartmouth Medical School researchers found that people who drank two cups or more daily were 35 percent less likely to get squamous cell carcinomas than non-tea drinkers.
Pop Open a Bottle
You've probably been hearing about red wine's role as a potential cancer fighter for years. While there's a strong Mediterranean wine culture, Fortes's data showed neither a protective nor a harmful effect on melanoma in wine drinkers. In the Australian study, however, people who drank a glass of wine every couple of days on average — red, white, or bubbly — reduced their rate of developing actinic keratoses (those precancerous skin patches or growths) by 27 percent. "Components in wine, such as catechins and resveratrol, may be tumor protective partially because of their antioxidant properties and may also inhibit growth of some human cancer cells," explains study coauthor Adele Green, MD, PhD, deputy director and head of the cancer and population studies laboratory at the Queensland Institute of Medical Research. While scientists get to the bottom of wine's possible health benefits and the mechanisms behind them, we propose a toast to the promising indicators. Cheers to healthy, beautiful skin!
"It's not any one antioxidant or fancy supplement that makes a difference in cancer risk," says Karen Collins, RD. "Rather, the compounds seem to function synergistically." So your best bet is to regularly get a variety in your meals and snacks. Here's where to find the powerhouse substances.
Beta-carotene: carrots, squash, mangoes, spinach, kale, sweet potatoes
Lutein: collard greens, spinach, kale
Lycopene: tomatoes, watermelon, guava, apricots
Selenium: Brazil nuts, some meats and breads
Vitamin A: sweet potatoes, milk, egg yolks, mozzarella
Vitamin C: many fruits and berries, cereals, fish
Vitamin E: almonds and other nuts; many oils, including safflower and corn
Source: National Cancer Institute
7 Must-Know Skin Cancer Risk Factors
By Samantha Shelton
New research reveals surprising reasons you may be at risk. Do any of these apply to you?
Human papillomavirus, which affects at least 50 percent of sexually active people, has been linked to cases of squamous cell carcinoma, according to a study published in a 2010 issue of the British Medical Journal. Talk to your gynecologist about protecting yourself against HPV and whether the HPV vaccine is a good option for you.
Tetracycline and related antibiotics make your skin more sensitive to sunburn, so avoid sun exposure while taking them and always wear ample sunscreen before venturing outside.
Working indoors all week and then getting intense sun exposure on weekends, especially if you're exercising (sweat wipes away sunscreen, leaving your skin more vulnerable to UV penetration), can up your risk, according to the American Cancer Society.
The High Life
States such as Utah and New Hampshire, which are very mountainous, have more people who have developed melanomas than do, say, Wisconsin and New York, the CDC reports. The levels of UV radiation increase 4 to 5 percent for every 1,000-foot increase in altitude.
A Weakened Immune System
People who take prednisone, which can be used for asthma and other conditions, and immunosuppressant drugs are at an increased skin cancer risk because their immune defenses are lowered and less able to protect cells from UV damage.
One in eight women will get breast cancer during her lifetime. Having the disease ups the odds of developing melanoma, too, according to a study in the Irish Journal of Medical Science. As researchers investigate a possible genetic link between the two cancers, be sure to stay up-to-date with your breast exams.
People who have 10 or more atypical moles, which resemble melanoma but are benign, have 12 times the risk for developing melanoma compared with the general population, according to the Skin Cancer Foundation. Even if you have just one mole, be vigilant with self-skin checks.
Originally published in FITNESS magazine, May 2011.