How a Plant-Based Diet May Help You Prevent Cancer and Manage Side Effects of Cancer Treatment

When you want to lower your risk for cancer, what you eat can help. While some people have a higher risk of developing cancer due to genetics, research shows good nutrition alone could prevent nearly 25% of all cancer cases. And a healthy diet may help patients with cancer better manage treatment-related side effects.

But what is a healthy diet? The American Institute for Cancer Research recommends the New American Plate, a filling, balanced, and nutritious approach to eating. The plan calls for vegetables, fruits, whole grains, and beans to make up at least two-thirds of each meal, and animal protein to make up the rest. Essentially, it’s a creative and flexible plant-based diet.

Plant-based diets focus on fiber, vitamins, and other natural substances, such as phytochemicals, to promote good health. The diet doesn’t prohibit eating meat but does limit portion size. And this diet can:

• Strengthen your immune system to help fight disease
• Reduce harmful inflammation to protect arteries, organs and joints
• Balance hormone levels, which can improve sleep and mood
• Improve your bowel health
• Help you manage your weight

Rachel Keller, MS, RD, a clinical dietitian at Winship Cancer Institute of Emory University, encourages people to follow a plant-based diet to prevent and fight cancer. “Good nutrition can’t solve everything,” she says. “But it is something we can do every day to take control of our health.”

Keller says people first notice healthier bowel movements when transitioning to a plant-based diet. “A plant-based diet is high in dietary fiber, which increases the weight and size of your stool and softens it,” she says. “Healthy bowel movements are a sign of good gut health, which lowers your risk for heart disease, obesity, and other conditions that make you sick and more likely to get cancer.”

Keller, a board-certified specialist in cancer nutrition, sees patients at all Winship Cancer Institute locations. As an integral part of the care team, she provides outpatient nutrition screenings, guidance about healthy eating, and personalized diets to help with treatment side effects such as nausea and weight loss. Patients at every phase of their cancer journey seek her help.

Many of Keller’s patients worry they won’t get enough protein with a plant-based diet, a misconception she happily debunks. “Protein intake is important for people receiving active cancer treatment, such as chemotherapy and radiation therapy, because it helps heal tissues, build and maintain muscle, and fight infection,” she explains. “A plant-based diet includes good protein sources, including fish, poultry, lean red meat, eggs, low-fat dairy products, nuts and nut butters, dried beans, peas, and lentils.”

Keller says many patients also ask if a vegetarian or vegan diet would be even better for them than a plant-based one. The answer is no. “There isn’t any scientific research that says these more restrictive diets are better, but we do know that they can create nutrition gaps,” Keller explains. “A vegetarian diet doesn’t include any foods made from animals, and a vegan diet goes one step further by also eliminating animal by-products such as eggs and dairy. These diets make it very difficult to get nutrients such as calcium, iron, zinc, and vitamin B12, not to mention protein.”

Since people with cancer often deal with treatment side effects, such as lack of appetite, nausea, tiredness, and changes to their sense of taste, a diet with more variety is better. “If someone is already a vegetarian or vegan, we’ll do labs to ensure their nutritional needs are being met,” Keller says. “Otherwise, we steer people toward a plant-based diet, which is easier to follow and can provide all the nutrients they need.”

It may take time to fully embrace a plant-based diet, especially for people used to a more traditional American diet or who don’t eat many fruits and vegetables. The key is to start with small changes. Keller recommends the following:

• Make your meat portions smaller than you’re used to—a 4-ounce chicken breast instead of an 8-ounce chicken breast, for example.
• Make Mondays meatless to start the week off with a plant-based menu.
• Keep extra vegetables in the fridge and add them to whatever else is on your menu.
• Eat a salad with lunch and dinner.
• Experiment with different grains, such as quinoa and Japanese buckwheat noodles.
• Explore new recipes with the help of the Internet—a quick Google search for plant-based recipes yields 702 million results!

As you make healthy changes to your diet, it’s essential to monitor your protein intake, especially if you have cancer. The current recommended daily allowance for protein for most adults is 46 to 56 grams per day, and people with cancer may need more. A registered dietitian can provide personalized guidance.  

Keller’s work at Winship Cancer Institute of Emory University educates people with cancer about nutrition’s impact on their health. In addition to outpatient appointments, she hosts a monthly nutrition support group for patients, cancer survivors, and their family members. The meeting covers wide-ranging topics—anything from how to maintain good bone health with vitamin D to how to stay hydrated while receiving cancer treatment. To learn more, visit our Cancer Support Groups page. 

Dietitians at Winship Cancer Institute of Emory University work closely with patients before, during, and after cancer treatment. They create personalized nutrition plans and address concerns such as poor appetite, weight loss, and treatment side effects. To schedule an appointment with one of our dietitians, call 404-778-5646.