Reduce Cancer Risk: Change Your Diet
Researchers estimate that one-third of cancer deaths are due to diet and lack of physical activity – nearly as many as caused by tobacco. In fact, for Americans who don’t smoke, eating the right foods and getting exercise are the most important things they can do to prevent cancer, according to the American Cancer Society.
Studies have shown numerous connections between food and certain cancers. High-fat dairy is associated with prostate cancer. Red meat and processed meats are linked to colon and rectal cancer. Alcohol directly causes cancers of the mouth, throat and liver, and it raises a woman’s risk for breast cancer.
So you might ask: If certain foods help cause cancer, can changing your diet lower your cancer risk? Absolutely, says Jennifer Brown, M.D., a Mills-Peninsula oncologist. While your genetics and environment also influence your cancer risk, your diet is a key factor you can control.
Want to reduce your cancer risk? Follow these recommendations from Dr. Brown and Debbie Kurzrock, R.D., a Mills-Peninsula registered dietitian who works in Radiation Oncology at the Dorothy E. Schneider Cancer Center in San Mateo.
Stock up on Colorful Veggies and Fruits
Plants protect us from cancer better than any other food. “The cancer prevention diet is really about eating a variety of plant foods: legumes, cruciferous foods like broccoli and cauliflower, and colorful fruits and vegetables,” Kurzrock says.
Most vegetables are loaded with dietary fiber, which is linked to a reduced risk of colorectal cancer. They contain antioxidants, which reduce damage from free radical molecules in the body. They’re rich sources of different phytochemicals that may help prevent lung, mouth, stomach and esophageal cancer.
“Opt for vibrant colors,” she says. Orange carrots and peppers contain beta-carotene, which helps maintain healthy tissue. Green kale and spinach are loaded with vitamins A, C and K, plus plant protein. Yellow bananas give you potassium. Apples, berries and cherries are rich in antioxidants.
Wine gets headlines for its heart benefits, but most people forget to read the fine print. Women should limit alcohol to one drink a day; men to no more than two drinks a day.
“Alcohol is a Group 1 carcinogen. We know it causes cancer,” Dr. Brown says.
Alcohol causes cancer of the liver, the esophagus, the throat and the mouth. It’s also linked to an increased risk of breast cancer and colorectal cancer, and may be associated with pancreatic cancer. When alcohol metabolizes in the body, it creates a chemical called acetaldehyde, which can damage DNA. Although researchers don’t fully understand how alcohol causes cancer, they suspect acetaldehyde plays an important role.
“If you want to enjoy one glass of wine, that’s fine,” Dr. Brown says. “Everything in moderation.” But stop after that first glass or two.
Measure Your Meat
People who eat a lot of processed meats like hot dogs, salami and deli meats have higher rates of colorectal and stomach cancer. Grilling, frying or broiling red meat at high temperatures is also linked to colorectal cancer.
Scientists theorize that preserving and grilling meat creates carcinogenic chemicals that may help cause cancer. Braising, stewing, steaming and microwaving meat may reduce the risk.
But the smartest strategy is to limit red meat, Kurzrock says. She suggests no more than 18 ounces a week of red meat such as beef, lamb and pork. Since most people eat four or five ounces at a time, that’s three or four servings a week.
And bacon? Loaded with saturated fat, high in cholesterol and heavily processed, bacon tops the list of foods to avoid. “Don’t consider bacon a meat,” she warns. “Treat it as a condiment.” Fry one slice and sprinkle small pieces over a salad or potato when you crave the flavor, but don’t indulge in a large side dish.
If red meat increases your cancer risk, can fish lower it? The omega-3 fatty acids in fish have long been linked to better heart health, but it’s not clear if they reduce the risk of cancer. In animal studies, omega-3s suppress cancer cells, but this effect hasn’t yet been demonstrated in people.
The best advice for now: Follow the Dietary Guidelines for Americans and eat two four-ounce servings of fish a week for protein and heart health. Choose cold-water fish such as salmon or sardines. Avoid farmed fish, which often has higher levels of pollutants, and large fish such as swordfish, king mackerel and tuna that can contain high levels of mercury, dioxin and other toxins.
Maintain a Healthy Weight
No matter what you eat, a healthy weight protects you from cancer more than all the other nutrition tips combined. The American Cancer Society says that obesity is blamed for 14 to 20 percent of cancer deaths in the United States. Being overweight is clearly linked to cancer in the breast, the colon, the kidneys, the esophagus, the endometrium and the pancreas.
Talk to your doctor about monitoring your body mass index (BMI) and keep it within a healthy range. Try to get at least 30 minutes of physical activity five days a week – an hour a day is even better.
“The best diet to fight cancer is a simple one high in fruits and vegetables and low in processed and red meat,” says Dr. Brown. “If you’re really doing your best to eat a lot of vegetables, fruits and cold-water fish such as salmon, you’re probably doing just fine.”
Debbie Kurzrock, R.D., is a Mills-Peninsula registered dietitian who works in Radiation Oncology at the Dorothy E. Schneider Cancer Center in San Mateo.