Making the connection between diet, exercise and cancer


Numerous studies show that eating right, exercising and maintaining a healthy weight can decrease a woman’s risk of getting breast cancer. Similarly, current evidence in breast cancer survivors (those who are undergoing or have completed treatment) suggests that weight loss and physical activity can reduce mortality from breast cancer.

But with headlines constantly touting the latest superfood, exercise routine or weight-loss program, what and whom should women listen to when it comes to their bodies?

It’s all about finding balance, says Sagar Sardesai, MD, assistant professor, breast medical oncologist and researcher at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James).

“Diet, exercise and weight are three separate issues,” Sardesai says. “And there is solid evidence for physical activity and weight loss when it comes to reducing risk of breast cancer and increasing chances of survival in women who have been treated successfully for the disease.

“When we discuss risk factors such as obesity, diet and exercise, what we know is that there is an association between these risk factors and chance of certain cancers,” he adds.

For instance, obese post-menopausal women are 20 to 30 percent more likely to get breast cancer than menopausal women with a normal body mass index (BMI). In addition, there have been multiple observational studies that show obesity at the time of cancer diagnosis is associated with increased likelihood of recurrence and mortality in breast cancer survivors.

“We are trying to better understand the underlying biological mechanisms that will explain how obesity and weight gain drive breast cancer growth,” Sardesai says.

“Exactly how the risks are reduced is not yet clear,” he continues. “But we do know that exercise can reduce inflammation and favorably impact our immune system, which makes the body less susceptible to cancer.”

In addition to finding balance, Sardesai says, it’s best to keep things simple and practice moderation. There is no magic cure, but women can make educated and informed decisions.

“It seems natural and logical that doing these things can help us,” Sardesai says. “These are things that are within a patient’s control. And, unlike a pill, there are no side effects.”

Sardesai makes the following recommendations:

Exercise — Get at least 150 minutes of aerobic activity per week. That could be 30 minutes of brisk walking five days a week. Strength training is also important, which Sardesai suggests doing at least twice a week.

Diet —Sardesai says he doesn’t prescribe to any specific diet; rather, he advises eating a diet rich in fruits and nonstarchy vegetables. Restrict dietary fat to 15 to 20 percent of your caloric intake a day and get most of your calories from healthy carbohydrates. Protein intake should be about .5 grams per pound (however much a person weighs) per day.

Weight — A healthy BMI is between 20 and 25. Anything above 25 is overweight, and anything above 30 is considered obese. Even if a woman does everything right, there’s no guarantee that she won’t get breast cancer.

“Although current evidence suggests that weight loss and physical activity have a protective effect, this is not absolute. It reduces a woman’s risk, but it does not prevent or eliminate it altogether,” Sardesai says.

Diet and physical activity have multiple other health benefits, including physical and psychosocial. Healthy habits in parents are more likely to be picked up by their kids, and that will eventually help this obesity epidemic, he says.

“At the end of the day, we can only do so much with what is within our control. These are measures that have been shown to reduce breast cancer risk, and our chances are better if we are healthy and have a normal BMI,” he says.

Learn more about breast cancer treatment and research at the OSUCCC – James.