After a routine skin check in 2000, I was diagnosed with a malignant melanoma, the most insidious of skin cancers. The phone call from my dermatologist with the initial news was one of those mind-bending times when life metamorphoses in an instant. In a deeply insensitive moment, the oncologist would say to me: “You know you did this to yourself, don't you?” When my tears started to well, he backpedaled vigorously, explaining that our generation, himself included, was guilty of unadulterated sun worship: the baby oil, the foil-covered reflective screens, the long SPF-free days at the beach. My cancer could, in fact, have been prevented.

We know that lighting up can lead to lung cancer, the top cause of cancer death in the United States, so stubbing out the cigarette is a no-brainer. But what about other cancers? Is it simply a case of bad genes and bad luck? Is it just a few renegade cells mutating and replicating at random? Increasingly, research suggests otherwise: How we live — what we eat, how active we are, how we choose to indulge during happy hour — impacts us at the cellular level. You might have a tumor-suppressing gene built into your DNA, for example, that gets switched off by environmental factors, opening a gate for abnormal cell growth. And while we'd all like to think the Big C won't happen to us, the stats are alarming: The average American has a 40 percent chance of developing cancer over a lifetime. On the upside, 80 percent of all cancers are related to lifestyle — diet, smoking, inactivity, and the like. You have little hope of changing your odds in Vegas — eventually you will lose at roulette — but if you can improve the odds of living cancer free, why not stack the deck in your favor?

Lose weight

In November 2007, the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) published a voluminous report — Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective — for which world experts analyzed 7,000 cancer studies. One of the most significant findings: Excess body fat is consistently linked to an increased cancer risk, specifically for cancer of the esophagus, pancreas, colon and rectum, endometrium, kidneys, and breasts. Adding to the evidence, a study published in The Lancet in February 2008 showed a link between obesity and at least a dozen cancers. Researchers found that an average weight gain of just 33 pounds in men increased the risk of esophageal cancer by 53 percent.

“There's an enzyme machinery in fat cells that leads to the production of hormones like estrogen, which plays an important role in the reproductive cancers,” explains David Schottenfeld, MD, MSc, professor emeritus of epidemiology and internal medicine at the University of Michigan and a member of the medical advisory board for the Prevent Cancer Foundation. The fat cells in an expanded waistline can also cause a state of chronic inflammation. “That smoldering inflammation can lead to the promotion of tumor growth,” says Schottenfeld. Researchers also point to insulin levels as another obesity-related cause of cancer. Bottom line: As the American population grows ever rounder, cancer rates are destined to rise.

Go easy on T-bones

Red meat — which means beef, pork, and lamb — does have its benefits. It's high in protein and iron. But it comes with a price tag. Red meat has been strongly linked to colorectal cancer, for one. “When red meat is exposed to high temps — frying, broiling, grilling — there's a chemical reaction that forms heterocyclic amines, or HCAs, which are known carcinogens,” explains Ann G. Kulze, MD, author of Dr. Ann's 10-Step Diet (Top Ten Wellness and Fitness, 2004). Another carcinogen lurks in your steak's charred crust: Polycyclic aromatic hydrocarbons result when the fat renders out and hits flame or smoke. “It's a hazardous fat-fire reaction,” says Kulze. If you just can't give up red meat, she recommends marinating and precooking it for two minutes in the microwave, trimming as much fat prior to grilling, and shaving off the charred bits afterward.

While you don't need to completely eschew the steaks and burgers (eating less than 18 ounces of red meat weekly is not associated with an increase in cancer risk), the AICR suggests eliminating nitrite-preserved processed meats altogether — any amount of which increases your risk of cancer. That means hot dogs, salami, ham, bacon, and sausage are out. “When you eat processed meat, the bacteria in your GI tract transform the nitrites into nitrosamines, a potent class of carcinogens,” says Kulze.

Next page: physical activity, sun protection, get tested

Keep the gym membership

Getting off the couch will help you trim down, which has been proven to reduce the risk of cancer. But the physical activity itself can also offer cancer-prevention benefits. Research shows that regular exercise can reduce the risk of colon cancer by as much as 40 percent and breast cancer by up to 80 percent. Studies have also shown physical activity slows the progression of prostate cancer and reduces the risk for lung and endometrial cancers.

In terms of colon cancer, hitting the gym may help keep your bowels regular — and the quicker potential carcinogens move through your system, the better. Physical activity also suppresses estrogen production, which in excess can increase the risk of breast and other cancers.

“Ideally you should sustain physical activity throughout your life,” says Christine Friedenreich, PhD, a research scientist with the Alberta Cancer Board. But it's never too late, she says. Her research showed women who were inactive early in life but who became active after menopause had a 40 percent decreased risk of breast cancer. The Centers for Disease Control and Prevention recommends at least 30 minutes a day of “moderately intense” exercise, five or more days a week. An hour a day would be even better, says the AICR. And you don't need to join an expensive club to do it. Jack up that heart rate by doing active yard work or by taking the stairs instead of the elevator.

Don't fry

Skin cancer is the most common cancer in the U.S., affecting 1 million people each year. It's also preventable (think wide-brimmed hats, broad-spectrum sunscreen, and indoor playtime during peak sun hours) and 99 percent treatable if caught early, like mine. But here's news: A recent study by researchers at St. Louis University School of Medicine in Missouri suggests that people who spend a lot of time in the driver's seat are more likely to develop skin cancer on their left arms, hands, heads, and necks. And drivers who roll up the windows are not immune. “Windshields tend to be laminated and tinted, so they have more of a filtering effect, while the side windows in most cars are not, which means less protection,” explains lead researcher, Scott W. Fosko, MD, a professor and chairman of the department of dermatology at St. Louis University. Before you get behind the wheel, slather up with a broad-spectrum sunscreen or wear a long-sleeved shirt. And if you're planning a long road trip, consider an aftermarket window treatment or tinting for your car's side windows.

But do get some sun

That said, new research suggests that vitamin D — which the body produces with the help of sunlight — may protect against a host of cancers, namely colon, breast, prostate, endometrial, and ovarian. A study published in January 2008 in the Journal of Epidemiology and Community Health showed a link between lung cancer rates and sun exposure, with greater rates of lung cancer in countries farther from the equator. “Smoking accounts for 90 percent of lung cancers,” says study author Cedric F. Garland, DrPH, epidemiology professor at the University of California, San Diego. “We believe vitamin-D deficiency accounts for the remaining 10 percent.”

He recommends getting a blood test to determine your vitamin-D levels. “It's as important as getting your cholesterol checked,” says Garland. To boost your levels: Strip down to shorts and a halter — you want 40 percent of your skin showing — and a floppy hat. Soak up the rays for between 5 and 20 minutes, depending on your skin type (the fairer you are, the shorter the duration). For some people (green-eyed, red-headed Celts, like me), the risk of skin cancer may outweigh the benefits of sunshine-induced vitamin D. Backup plan: Take a vitamin D3 supplement in the amount of 1,000-2,000 IU a day. Although vitamin D is found in food sources, Garland says, you'd have to drink ten to 20 glasses of milk a day to get a sufficient dose.

Get tested

Screening is a key component of prevention. Cancer prognosis can be exponentially better if you can catch the disease in its early stages. The survival rate for breast cancer, for example, is 98 percent at five years if the disease is caught when it is very localized. Colon cancer, second only to lung cancer as a cause of death and equally prevalent among men and women, is totally preventable if precancerous polyps, growths that have long been considered the main precursors for colon cancer, are removed in time.

Colonography is a new way of screening that's less invasive than the dreaded colonoscopy. This virtual colonoscopy uses a CT scan to examine the colon. The sticky wicket: A study published in the Journal of the American Medical Association in March showed depressed or flat lesions were five times more likely to be cancerous than polyps. While the CT scan would clearly be more comfortable, a traditional colonoscopy better detects these flat or depressed lesions. Also be picky when it comes to the experience behind the scope. A study in the New England Journal of Medicine found certain doctors were ten times better at finding precancerous polyps — and the flat lesions are even harder to detect.

Always check with your doctor to see what your own medical history dictates, but most women ages 21-30 should have a Pap test every year and then every three years if they've had negative results for three years in a row, and a mammogram every two years after age 40. Both genders should have colonoscopies every ten years after age 50. Plan annual physicals and regular skin checks, too.

Despite the efforts of award-winning writer Helen Olsson to feed her three children wholesome food, the youngest still won't eat kale.

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