Food choices to help reduce cancer risks
by staff from the Fred Hutchinson Cancer Research Center
This article was originally published in February 2019
Many of us know that eating healthy foods and getting exercise are important for our health. But we may not realize how those practices may help reduce risks of cancer.
In honor of February as National Cancer Prevention Month, experts from Fred Hutchinson Cancer Research Center share some of the science associating diet with cancer prevention.
Cancer prevention researcher Dr. Anne McTiernan has worked with the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) to review the latest scientific evidence and create a comprehensive report on lifestyle factors that can affect your health. The bottom line? Many cancers may be prevented by changes in diet, nutrition and physical activity.
Here are some of McTiernan’s top tips for reducing cancer risks through food:
Eat a diet rich in vegetables, fruits, whole grains and legumes. Get at least five daily portions of fruit and non-starchy veggies, such as broccoli, kale, spinach, eggplant, carrots, cabbage and celery. “By eating mainly vegetables,” McTiernan notes, “you’ll take in fewer calories and healthy dietary fiber to keep your body running smoothly all day.”
Aim for at least 30 grams of fiber a day. Whole grains are a great fiber source and the bran and germ of the grain contain compounds with anti-cancer properties. Fiber also is a mainstay of legumes, such as peas and beans. All these foods provide abundant nutrients and cancer-fighting phytochemicals and contribute to faster gut-transit time (meaning less exposure to carcinogens). Research finds that people who eat whole grains every day have a lower risk of colorectal cancer.
Preparing your own meals is healthier. “Eating out usually means less individual control over ingredients and larger portion sizes,” says McTiernan. “The more you buy and cook your own food, the more control you have over maintaining a healthy diet.”
Limit consumption of red and processed meat. Keep red meat consumption (beef, veal, pork, lamb or any other red “muscle meat”) to no more than three portions per week. The World Health Organization has classified red meat as “probably carcinogenic” due to its link to colorectal, prostate and pancreatic cancer.
Eat little to no processed meat (i.e., anything salted, cured or smoked), as it is high in fat and sodium and contains curing agents, such as nitrites, shown to be detrimental to our health. According to WCRF and AICR, for every 50 grams of processed, preserved or cured meat eaten per day (equivalent to roughly two slices of bacon), your risk for colorectal cancer increases by 16 percent.
Dr. Marian Neuhouser, a nutritional epidemiologist, leads Fred Hutch’s Cancer Prevention Program and is a past president of the American Society for Nutrition. Dr. Neuhouser believes healthy eating is all about the big picture, not the small slip-up.
“Having one day where you don’t eat particularly well is not terrible,” she says. “It’s the whole dietary pattern over the course of one’s life that’s important.” Here are her tips for improving diet to lower cancer risk:
Read labels and watch for extra sodium, sugar and fats. One way to make sure you’re avoiding too much fat, sodium and sugar is by reading labels. The WCRF has linked high-salt food to stomach cancer and too much salt also can raise blood pressure.
“Sodium is one of the major preservatives that we have,” says Neuhouser. “It’s in canned soups, crackers, cookies, breakfast cereals. Anything that has to remain shelf-stable probably has added salt and added sugar.”
Too much sugar or fat can cause weight gain, which in turn can lead to obesity, diabetes and some cancers. The WCRF, in fact, has now linked obesity (or being overweight) to risks of 13 different types of cancer.
Limit sugary drinks and alcohol. Stick with water and unsweetened beverages as much as you can (tip: a little lemon can give your water some zip).
Much like eating high-calorie foods, drinking beverages with sugar or added syrup — soda, sports and energy drinks, sweetened waters, fruit juices, and even coffee and tea-based drinks — packs on unnecessary calories and boosts the risk for multiple cancers as well as diabetes, cardiovascular disease, and fatty liver disease.
Alcohol is not much better. Research from leading health organizations, such as the American Society of Clinical Oncology, the WCRF and the AICR, consistently shows that the more you drink, the higher your risk of cancer, particularly mouth, pharynx, larynx, esophageal, breast, colorectal, stomach and liver cancers.
Researchers believe alcohol increases cancer risk in several ways. It creates the toxic chemical, acetaldehyde, when metabolized. It damages DNA, proteins and lipids through oxidation. It impairs the body’s ability to absorb necessary nutrients and it increases blood levels of estrogen, a hormone linked to breast cancer risk. If you do drink, try to stick to one drink a day.
Fred Hutch psychologist and smoking-cessation expert, Dr. Jonathan Bricker, researches ways to help people overcome behaviors that increase health risks, including cancer. Bricker’s advice goes beyond smoking to other behaviors, such as snacking, drinking and overeating.
Trying to tweak your behavior? Bricker recommends being mindful of “triggers” and paying attention to what you’re feeling before you grab a cookie, drink or cigarette.
“Be willing to just sit with those sensations rather than fight them,” he says. “If you can watch them for a few minutes, you may discover they are not so urgent. Sometimes they even go away.”
He offers these additional tips for building and keeping healthy habits:
Know what matters to you. Think about what will make the change worthwhile. Do you want to lose weight or quit smoking because you care about your own health or want to show your love for your family? “Dignify your resolutions with your values,” Bricker says.
Make a specific, achievable plan. Think small — as in gradual, sustained weight loss — instead of telling yourself you’re going to lose 10 pounds in a month. When you reach your goal, make another small goal. “Thinking big is daunting; thinking small can work.”
Be kind to yourself. Give yourself a break and allow yourself to slip up. “Surprisingly, giving yourself permission to mess up can make it easier to try again,” he says.
Messages, such as “eat your veggies” and “watch the booze,” may not sound cutting-edge. But after hundreds (even thousands) of studies, the science is clear. Big benefits can come from just a few lifestyle changes.