When it comes to preventing cancer, your best defense may be common sense: Up to 40% of cancers are caused by “lifestyle behaviors” like smoking, eating too much, and not exercising, according to a 2011 study in The British Journal of Cancer. “Most lung cancers are related to smoking. Most skin cancers are related to sun exposure. Most cervical cancers are related to HPV,” says Gregory Masters, MD, an attending physician at the Helen F. Graham Cancer Center in Newark, Delaware. “Genetics, on the other hand, are related to a fairly small number of cancers, maybe 10 to 15%.” As such, he says, “focusing on healthy behaviors is the most effective way to lower your risk of cancer.”
Here, 8 ways to boost your chances of staying disease-free.
1. Absolutely, positively, do not smoke
This is a no-brainer, but ditching the cigarettes is key when it comes to preventing cancer of all kinds. Smoking accounts for 30% of all cancer deaths, and lung cancer in particular kills more Americans than any other type. “Avoiding tobacco is one of the best ways to decrease your risk of cancer,” says Masters. Even cutting back from 20 to less than 10 cigarettes per day reduced smokers’ lung cancer risk by 27%, according a 2010 study in the Journal of the American Medical Association. “The less smoke exposure you have,” says Masters, “the better.” You can get help with quitting at smokefree.gov.
2. Keep an eye on the scale Packing on the pounds isn’t just detrimental to your waistline. According to the American Institute for Cancer Research (AICR), excess body fat is linked to an increased risk of nine cancers, including esophageal, kidney, and gallbladder. (Fat tissue produces proteins that cause inflammation, which promotes cell growth and ups the risk of cancer.) What’s more, the AICR estimates that more than 120,000 cancer cases in the U.S. every year are attributable to extra weight gain. “Certain lifestyle behaviors make maintaining a healthy weight more challenging today than ever,” says Patricia Ganz, MD, director of the Division of Cancer Prevention and Control Research at University of California Los Angeles’ Jonsson Comprehensive Cancer Center. “Fast food is cheap, and we spend more time with our TVs and computers than we do outdoors.
3. Sweat for at least 30 minutes a week When it comes to preventing cancer, exercising is just as crucial as eating right: One third of all cancer deaths in the U.S. every year are linked to diet and physical activity. While the American Cancer Society recommends getting 150 minutes of moderate exercise (or 75 minutes of vigorous activity) weekly, research has found shorter workouts can be effective, too. A 2010 study published in Nutrition and Cancer found that just 30 minutes of weekly physical activity was enough to reduce women’s chances of developing breast cancer—which affects 1 in 8 U.S. women—by 35%. “Physical activity alone has a lot of protective effects,” says Ganz. “Aside from helping to maintain a normal weight, it contributes to reducing inflammation.
4. Skip the booze…mostly
Alcohol is the culprit behind several cancers, including mouth, throat, liver, colon, and breast. The exact reason isn’t known, but researchers think alcohol may damage body tissue. In the colon, for example, bacteria can convert alcohol into large quantities of acetaldehyde, a chemical that’s known to cause cancer in lab animals. In women, consuming liquor causes levels of estrogen (the hormone involved in breast-tissue growth) to spike, which potentially increases the risk of breast cancer. The American Cancer Society recommends women limit alcohol consumption to one drink daily, but less is more, says Ganz. “A couple drinks a week isn’t a big deal, but daily drinking may carry some risk,”
5. Learn to love broccoli Vegetables aren’t only part of a healthy diet—they also have cancer-fighting properties. (That’s why the American Cancer Society recommends eating 2½ cups of fruits and veggies daily.) Cruciferous vegetables in particular—think broccoli, Brussels sprouts, and cabbage—are packed with chemicals called glucosinolates, which show anti-cancer effects when broken down into compounds during digestion. A 2000 study in Gynecologic Oncology, for example, found that one of these compounds reduced the growth of abnormal cells in a human cervix. Other cancer-fighting veggies: tomatoes, which contain lycopene, a phytochemical that blocks cell-damaging molecules called free radicals, and eggplant, which contains nasunin, an antioxidant that cuts off the blood supply that cancer cells need to multiply. Plus, loading up on veggies means you won’t have as much room for foods like red meat.
6. Stock up on sunscreen Women aged 18 to 39 are especially susceptible to melanoma, the deadliest form of skin cancer—their rates of the disease have shot up 800% in the last 40 years. Indoor tanning, which blasts the skin with DNA-damaging UV rays, is partly to blame, but exposure to the actual sun is harmful, too. Thankfully, the risk can be mitigated with a simple tube of sunscreen. A study of 1,600 people published in the Journal of Clinical Oncology in 2010 found that people who wore sunscreen daily were 50% less likely to develop melanoma than those who weren’t diligent sunscreen users. “You should be wearing a minimum of SPF 15 every day, even in winter and when it’s cloudy,” says Ganz, who also recommends avoiding the sun between 10 a.m. and 4 p.m., when UV rays are at their strongest. “Putting on sunscreen should be a habit, just like brushing your teeth.”
7. Relax already Stress alone doesn’t cause cancer, but it can “change the environment in the body so that precancerous conditions become more evident,” says Ganz. A 2013 study from Ohio State University found that chronic stress alters the activity of immune cells by priming them for the fight-or-flight response—which floods the body with hormones like cortisol—even if it’s unnecessary. This can lead to increased inflammation, which can potentially spark cancerous cell mutations. Thankfully, taking measures to reduce stress—anything from hitting the yoga studio to ignoring your work email after 7 p.m. each night—can lower inflammation levels. “The idea is to do things to make your body the healthiest place it can be,” says Ganz.
8. Screen yourself Getting screened can’t necessarily prevent cancer, but it can alert doctors to precancerous warning signs (like a polyp in your colon or a suspicious-looking mole). That’s why the American Cancer Society recommends getting screened for cancer as early as in your 20s. Women should undergo a clinical breast exam every three years until age 40, when annual mammograms become key (according to the Prevent Cancer Foundation, screening can reduce your risk of fatal breast cancer by as much as 25%); Pap smears, which can detect cervical cancer, are recommended every three years (cervical cancer deaths have dropped 74% since the 1950s, mostly due to Pap screening); and checks for colon cancer should start at age 50 (or sooner if there’s family history of the disease). “Catching cancer early is critical,” says Masters, “and early cancer is much more curable.”