The guidelines largely reflect previous advice about preventing cancer. The new advice, however, homes in on exercise duration and specific foods to avoid or limit. As many as 20 percent of all new cancer cases in the United States can be attributed to poor diet, obesity, inadequate physical activity, and alcohol intake, the authors say. The recommendations are based on a review of scientific evidence conducted by the International Agency on Cancer Research (IARC) and other major nonprofit and government health groups, says Laura Makaroff, DO, the senior vice president for prevention and early detection at ACS. “The recommendations reflect the totality of the evidence that has been published since the last guidelines were updated, in 2012,” she says. “There are a few areas that have received increased emphasis, and a lot has stayed the same.”
Even More Exercise Is Better for Preventing Cancer
The previous guideline for adults recommended at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity each week. The new recommendation calls for more: 150 to 300 minutes of moderate-intensity or 75 to 150 minutes of vigorous-intensity physical activity per week. Moreover, the guidelines point out that achieving or exceeding the upper limit of 300 minutes “may be more optimal.” “That is quite a bit different from previous recommendations,” Dr. Makaroff notes. And the ACS chose to make the recommendation even though many Americans struggled to meet the previous guideline, she says. According to a National Health Statistics report published in June 2018 by the U.S. Department of Health and Human Services, only 23 percent of U.S. adults ages 18 to 64 meet the guidelines for both aerobic and muscle-strengthening activities. “It’s really what the science is telling us in terms of how physical activity matters for cancer prevention and that we need to be doing even more,” says Makaroff, calling the new recommendation “a call to action.” As many as 18 types of cancer are linked to obesity and lack of physical activity, according to the report.
Planting a Red Flag on Red Meat, and Processed Meats and Foods
The updated guidelines for diet emphasize replacing the word “diet” with the phrase “eating patterns.” “A healthy eating pattern is an everyday choice and not just a time when you’re on a diet,” explains Makaroff. The guidelines define a healthy eating pattern as:
Foods that are high in nutrients in amounts that help achieve and maintain a healthy body weightA variety of vegetables—dark green, red, and orange, fiber-rich legumes (beans and peas), and othersFruits, especially whole fruits, in a variety of colorsWhole grains
The new guidelines specify foods to avoid, explaining that a healthy eating pattern does not include red and processed meats, sugar-sweetened beverages, or highly processed foods or refined grain products.
Moving From Alcohol in Moderation to Alcohol Avoidance
Another significant change in the recommendations is in alcoholic beverage consumption. The previous guideline stated that adults who drink should limit their consumption to no more than one drink a day for women or two drinks a day for men. The new guideline states: “It is best not to drink alcohol.” “We are recommending avoiding alcohol to reduce cancer risk,” Makaroff says. “Alcohol is a known risk factor for several different types of cancer, including liver, colorectal cancer, esophageal, breast cancer in women, and cancers of the head and neck.”
Addressing Disparities in Cancer Prevention
Finally, the ACS notes how challenging it is for some Americans to exercise and eat healthfully despite their best intentions. Many neighborhoods are devoid of safe spaces to exercise or lack grocery stores that carry an array of affordable fresh produce, lean meat, and seafood — areas commonly known as “food deserts.” A U.S. Department of Agriculture analysis identified approximately 6,500 food desert tracts in the United States based on 2000 Census and 2006 data. Conversely, several studies, such as those cited in a 2016 review published in Alcohol Research: Current Reviews, have shown that liquor stores are concentrated in some cities’ poorer neighborhoods. The guidelines call for public, private, and community organizations to work collaboratively at all levels of government to push for changes that increase access to safe exercise spaces and wholesome foods. That message is especially timely, says Steven Clinton, MD, PhD, a medical oncologist with the Ohio State University Comprehensive Cancer Center in Columbus, given the COVID-19 pandemic, which has impacted Black, Indigenous, and People of Color (BIPOC) groups more than white people because of higher rates of underlying health conditions, and in the light of the marches and demonstrations occurring nationwide to call attention to racial discrimination and injustice. “When you look at the last few months, [the guideline authors] didn’t know about the COVID-19 pandemic and some of the disparity issues [with that disease],” says Dr. Clinton. “They didn’t predict that. But I think it’s a very important piece of this document — the issue that government needs to take a role in public health.” Previous ACS cancer prevention guidelines also have focused on the need for more community and government action to strengthen preventive health measures in all communities, Makaroff says. But, she says, “we continue to emphasize that, knowing we are not where we need to be, [and] knowing that cancer is a disease that affects everyone — but it doesn’t affect everyone equally. No one should be disadvantaged in their fight against cancer.”
