When you hear the phrase “comfort food,” tomatoes and broccoli might not immediately spring to mind, but your perception could change as ongoing research evaluates whether increased intake of plant-based foods could slow the growth of prostate cancer.

In the Men’s Eating and Living (MEAL) Study, researchers are assessing how a diet that incorporates more vegetables affects prostate-specific antigen (PSA) levels and the Gleason score of men with early-stage prostate cancer. The randomized study, conducted at 180 locations across the U.S., tracks 464 men ages 50 to 80 with prostate cancer that has not progressed beyond stage T2a and who opted for active surveillance over treatment.

“We’re trying to prove that if men on active surveillance switch their diet to one that’s beneficial, they can decrease the growing and spreading of their prostate cancer,” reducing the number who will eventually need treatment and improving their quality of life, says J. Kellogg Parsons, associate professor of surgery at Moores Cancer Center at UC San Diego Health and protocol chairman of the study.

Making Long-Lasting Diet Changes

Improve your diet and stick to it with these tips.

Do you struggle to follow a healthy diet? John Foreyt, director of the Behavioral Medicine Research Center at Baylor College of Medicine in Houston, offers these tips for making long-lasting nutritional improvements.

  1. Record what you eat in a food diary after every meal. “The first step in behavior change is becoming aware of your current behavior,” Foreyt says.
  2. Identify any barriers to making a change. Do you dislike the taste of certain vegetables, or does a family member cook high-calorie meals? With this information, look at where changes can be made. Find vegetables you like, or talk about the dinner menu with your family. If the change doesn't work with your lifestyle, modify it until you find a good fit.
  3. Take the process slowly. Making a permanent diet change can be difficult, even when you know it’s good for you. “Anyone can do something for a day or two, but it’s easier to adopt something long-term if you can work it into your lifestyle,” Foreyt says.

Over 24 months, half of the participants receive telephone-based coaching from a counselor, along with written support materials and newsletters. Counselors aim to help participants develop confidence in their ability to change their behavior, establish goals, and make and maintain diet improvements by providing positive reinforcement and watching for signs of regression. The counseling focuses on increasing vegetable consumption to at least seven servings a day. The control group receives only nutrition guidelines from the Prostate Cancer Foundation and newsletters containing general dietary information.

Researchers measure the PSA levels of participants in both groups at regular intervals, perform biopsies after 24 months, and assess quality of life intermittently through questionnaires. They plan to complete the study by the summer of 2017. A pilot trial conducted in 2007 showed that over-the-phone counseling was effective in helping survivors improve their diets. 

​“The intervention simultaneously empowered them,” says Parsons. “It let them feel like they were doing something about their cancer.”