You already know that not smoking, maintaining a healthy weight, and drinking alcohol in moderation are keys to avoiding cancer. But what if you want to take cancer prevention one step further? What else can you do? Simple, say the experts -- eat right.
Though factors outside our control, such as genetics and environment, do play large roles in the development of cancer, a good diet can tip the scales in your favor.
Research shows that dietary patterns are closely associated with the risk for several types of cancer. The American Cancer Society estimates that as many as 35% of cancer deaths may be related to dietary factors.
"Diets low in fat and high in fiber, fruits, vegetables, and grain products are associated with reduced risks for many cancers," says Elaine Magee, MPH, RD, author of Tell Me What to Eat to Help Avoid Breast Cancer and Eating Well for a Healthy Menopause, among others. In one recent two-year study, she says, non-melanoma skin cancer patients on a 20%-of-calories-from-fat diet had five times fewer new skin cancers at the end of the study compared with patients in the typical 38%-of-calories-from-fat control group.
These American Institute for Cancer Research recommendations on diet and lifestyle can provide a starting point for your own cancer-prevention eating plan:
- Don't eat more than 3 ounces of red meat daily -- about the size of a deck of cards.
- Limit fatty foods.
- Avoid salty snacks, and use herbs and spices instead of salt as seasoning.
- Men should limit alcoholic drinks to two per day; women, to one per day.
- Do not eat charred food.
- Avoid being overweight. Limit weight gain during adulthood.
- Take an hour's brisk walk (or get equivalent exercise) daily.
Although Americans are slowly adopting healthier diets, a large gap remains between recommended dietary patterns and what we actually eat. According to the CDC, only about 25% of adults in the U.S. eat the recommended five or more servings of fruits and vegetables each day.
"Eating five to nine servings of fruits and vegetables every day will do a lot to decrease cancer risk," says Melanie Polk, RD, director of nutrition for the American Institute of Cancer Research, or AICR.
Getting that many servings doesn't have to be hard, says Polk.
"Make it simple," she says. "Add a handful of blueberries to your cereal in the morning. If you're having a sandwich at lunch, throw in lots of tomato slices as well as lettuce. Broccoli can be added to soups or sprinkled over pizza with olives, onions, and mushrooms. Instead of having a packaged snack in the afternoon, have an apple or banana. It all helps."
Plant foods appear to be most protective against cancer. They are rich in fiber, antioxidants, and helpful phytochemicals.
"Preliminary evidence supports the speculation that substances in flaxseed may help block substances that promote cancer," says Magee. "Omega-3 fatty acids, which are found in fish and certain plant foods, including flaxseed, have been shown in animal studies to slow or prevent the growth of certain cancers."
Diet for High-Risk People
A good diet can even help those with a family history of certain cancers beat the odds.
"A history of cancer in the family doesn't mean that every person in the family will get it," says Polk. "For someone at high risk, diet should be included as part of an early-detection screening plan set up by their doctor."
For the person already diagnosed with cancer, the nutrition picture is a little murkier. No single answer serves everyone.
"Body changes may be caused by the patient's response to the tumor, the side effects of treatment, certain medications, or some combination of these," says Magee. "Some dietary practices, like supplementing with flaxseed, might compete with a drug like Tamoxifen. That's why it's important to discuss diet with your oncologist."
Polk recommends that cancer patients work with a dietitian to make dietary decisions.
"When a patient gets involved in decisions like treatment and diet they feel less passive, more like they're part of their own healthcare team," she says.
Originally published Sept. 30, 2002.