Healthy diet, increased physical activity, and community support are cornerstones of cancer prevention

The American Cancer Society (ACS) has released its updated guideline “American Cancer Society Guideline for Diet and Physical Activity for Cancer Prevention.”

Published in CA: A Cancer Journal for Clinicians/Early View, the guideline is an update of nutrition and physical activity guidelines for cancer prevention. Focused on increased physical activity and developing healthy eating patterns throughout life, this updated ACS guideline emphasizes maintaining a healthy body weight throughout all stages of life.

“This guideline update reflects the totality of the current scientific evidence on diet activity in cancer risk since our last guideline on this topic was published in 2012. It’s been in the works for quite some time,” Laura Makaroff, DO, Senior Vice President, Prevention and Early Detection for The American Cancer Society told BreakingMED.

The updated recommendations included the following:

Maintenance of a Healthy Body Weight

The guidelines emphasize the need to keep body weight within healthy ranges and to avoid weight gain during adulthood. According to WHO classification, a normal body mass index (BMI) is one that is ˂25.0 kg/m2. Overweight is considered a BMI of 25.0 to 29.9 kg/m2, and obesity as ≥30.0 kg/m2.

In women, overweight and obesity accounted for roughly 10.9% of all cancers diagnosed in the United States in 2014, and in men, for 4.8% of cancers.

Previous evidence supports an association between excess body fat and postmenopausal breast, endometrial, renal cell, esophageal, and colon and rectal cancers. Later, this was expanded to also include gastric cardia, liver, gallbladder, pancreatic, ovarian, and thyroid cancers, as well as multiple myeloma and meningiomas. Other studies provide some evidence that excess body fat increases the risks of advanced, high-grade, or fatal prostate cancer as well as cancers of the oral cavity, pharynx, and larynx.

“Excess adiposity can contribute to a procarcinogenic environment through several carcinogenic pathways involved in inflammation, oxidative stress, cell proliferation and angiogenesis, inhibition of apoptosis/cell death, and metastases,” noted the authors.

Increased Physical Activity

For adults, a weekly goal of 150-300 minutes of moderate intensity activity or 75-150 minutes of vigorous intensity activity is recommended. Children and adolescents should strive for at least 1 hour of moderate or vigorous intensity activity daily. Optimal goals are those that meet or exceed 300 minutes/week of activity.

Individuals are also encouraged to limit their sedentary behaviors, including sitting, lying down, and watching television and other screen-based forms of entertainment.

Cancers that have been linked to a lack of physical activity include colon, breast, kidney, endometrial, bladder, esophageal, and stomach cardia cancers.

“Although there is some disagreement regarding the strength of the evidence, it is clear that evidence is rapidly accumulating and supports an important role for [moderate-to-vigorous physical activity] MVPA in cancer prevention for a greater number of cancers than previously believed,” wrote Rock and colleagues.

“It is estimated that 1.5% of all cancers diagnosed in the United States during 2014 in men and 4.4% of all cancers diagnosed in women are attributable to physical inactivity, as are 1.4% of all cancer deaths in men and 3.0% of all cancer deaths in women,” they added.

A Diet Rich in Fruits, Vegetables, and Grains

Perhaps the most notable shift in the guidelines is that rather than focusing on specific foods or nutrients, the ACS guideline now stresses healthy eating patterns at all ages.

“This new update does point to a healthy eating pattern versus a healthy diet or specific focus on certain nutrients, and that is for a couple of reasons. One, after a thorough review of the available scientific evidence, we know that a healthy eating pattern is what matters the most to reducing the risk of cancer through the foods we eat. We also recognized that people eat food and not nutrients, so helping people understand what a healthy eating pattern looks like throughout a lifetime [is important],” explained Makaroff.

Foods such as sugars, meat, fat, and processed foods increase the risks of developing certain types of cancer. The guideline calls for eating foods with many nutrients to maintain a healthy body weight, with an emphasis on including a variety of fruits, vegetables, and whole grains.

“Emerging evidence, largely epidemiological but also including a few controlled intervention trials, suggests that healthy (versus unhealthy) dietary patterns are associated with reduced risk for cancer, especially colon and breast cancer,” wrote Rock and colleagues.

Makaroff offered a few tips for clinicians in guiding patients to follow healthy eating patterns:

“The important part of describing a healthy eating pattern is to talk about that this is not just a diet to follow for the short-term, but is really about healthy habits and a healthy lifestyle throughout your life. A healthy eating pattern includes foods that are high in nutrients, in amounts that help achieve and maintain a healthy body weight, and that a healthy eating pattern also includes a variety of fruits and vegetables, including all the colors of the rainbow….and plenty of whole grains,” said Makaroff.

It’s also important for clinicians to emphasize the things that are not included in healthy eating patterns, she continued. This includes avoiding readily available fast foods, red and processed meats, sugar sweetened beverages, and all the other highly processed foods and grain products “that are so much a part of our American diet,” she added.

Alcohol Avoidance

Because the consumption of alcohol has been linked to increased risks of several cancers, the guideline recommends avoiding alcohol to reduce cancer risks. For those who do choose to drink, the recommendation is for limited consumption, with no more than one alcoholic beverage per day for women, and no more than two per day for men.

“Alcohol consumption is the third major modifiable cancer risk factor after tobacco use and excess body weight. Alcohol consumption is an established cause of at least 7 types of cancer,” wrote the authors. “Broadly, the carcinogenic effects of ethanol found in alcoholic beverages and acetaldehyde involve DNA and protein damage and alterations, oxidative stress, inhibition of DNA repair and cell death, increased cell proliferation, nutritional malabsorption, changes in DNA methylation, and, for breast cancer, increased estrogen levels. In addition, carcinogenic contaminants can be introduced during alcoholic beverage production,” they added.

Community Support

Finally, the ACS guideline calls for community organizations to work together to develop policy changes to support the new guidelines by increasing access to affordable, nutritious foods as well as increased access and opportunity for physical activity within the community.

“In addition to the individual choice, community-level action and having the right environments for patients to live in, having the right policies in place to help support healthy diets and physical activity are also super-important,” said Makaroff.

“As clinicians, we have a role in both places, and an opportunity to make an impact both on the individual patient level and also on the population level and the policy level as we influence our communities, our institutions to have all the right environmental factors and policies in place that help support healthy lifestyles,” she added.

“The important thing is to recognize that excess body weight, limited physical activity, unhealthful diets, and alcohol account for almost 20% of cancer cases in the United States every year. That’s the second highest proportion for any risk factor after cigarette smoking for both men and women. Helping patients make healthy choices and have healthy lifestyles is so important for cancer prevention,” concluded Makaroff.

  1. The American Cancer Society (ACS) has released its updated nutrition and physical activity guidelines for the prevention of cancer.

  2. Maintaining a healthy body weight throughout life, as well as adhering to healthy diet and getting adequate physical activity are the primary recommendations from the ACS; alcohol avoidance and community support are important as well.

E.C. Meszaros, Contributing Writer, BreakingMED™

Rock reported no disclosures.

Cat ID: 935

Topic ID: 78,935,730,935,192,94