February is National Cancer Prevention Month. A recent study conducted by epidemiologists at the American Cancer Society found that at least 42 percent of newly diagnosed cancers in the U.S. are potentially avoidable. Some of these cases include cancers caused by smoking, excess body weight, physical inactivity, excess alcohol consumption, poor nutrition and excessive sun exposure.
When it comes to what we eat, there are no magic ingredients to incorporate or avoid that will prevent cancer.
However, there are certainly foods that are more nutritious and beneficial than others and should be consumed more often. Unfortunately, many of the lists circulating that identify specific ingredients to avoid or add to one’s diet to prevent cancer are often sensationalized and part of a fad diet. The term "superfood" does not even have a legal definition and is mainly used as a marketing tool.
For cancer prevention, it’s about a lifestyle that includes certain foods groups to limit (not necessarily avoid) and some food groups to choose more often.
The main cancer prevention tips — as recommended by the World Cancer Research Fund and the American Institute for Cancer Research in their Third Expert Report published in 2018 — are as follows:
1. Maintain a healthy weight. Keep your weight within the healthy range and avoid weight gain in adulthood. For example, excess body fat increases the risk for postmenopausal breast cancer, in addition to 12 other cancers.
2. Be physically active as part of everyday life. In other words, walk more and sit less.
3. Eat a diet rich in whole grains, vegetables, fruits and beans. Make whole grains, vegetables, fruits and legumes such as beans and lentils a major part of your usual daily intake. Plant foods contain fiber and other nutrients studied for their role in lowering cancer risk; they can also help individuals with weight control.
According to the American Institute for Cancer Research, research shows that soy foods in moderate amounts are safe for those diagnosed with cancer and those without. Soy foods contain fiber, nutrients and phytochemicals studied for their cancer prevention properties. For individuals with hormone-sensitive cancers, it is recommended to avoid soy pills and isoflavone-enriched powders.
4. Limit consumption of fast food and other processed foods high in fat, starches or sugars. Limiting these foods helps control calorie intake and maintain a healthy weight.
5. Limit consumption of red and processed meat. Eat no more than moderate amounts — less than 18 ounces per week — of red meat such as beef, pork and lamb. (Although a highly successful marketing campaign might say otherwise, pork is still classified as red meat.) Eat little, if any, processed meat.
6. Limit consumption of sugar-sweetened drinks. Drink mostly water and unsweetened drinks. Good news for coffee lovers: According to the American Institute for Cancer Research, strong probable evidence suggests that drinking black coffee may reduce the risk for endometrial and liver cancer. Coffee itself has essentially no calories, but adding whole milk, whipped cream, chocolate, sugar or syrup flavorings can turn coffee into a meal’s worth (or more!) of calories.
7. Limit alcohol consumption. The best advice for those concerned about cancer is not to drink due to strong evidence that alcohol consumption increases the risk for multiple cancers. If you do choose to drink alcohol, however, limit your consumption to a maximum of one drink for women and two for men per day. One "drink" is defined as a 12-ounce regular beer, 8 to 9 ounces of malt liquor, 5 ounces of table wine and 1.5 ounces of 80-proof liquor.
8. Do not use supplements for cancer prevention. Aim to meet nutrition needs through diet alone. Always discuss with your medical team all medications and supplements you are currently taking and before you plan to start anything new.
9. For mothers, breastfeed your baby if you can. Breastfeeding is good for both mother and baby. There is strong evidence that breastfeeding helps protect against breast cancer in the mother.
10. After a cancer diagnosis: Follow these recommendations if possible. Check with your health professional about what is right for you.
Patricia Champion, MS, LD, is a registered dietitian at CARTI Cancer Center.