Eating with Cancer

December 1, 2018

Person in a green robe holding a fresh bunch of leafy greens close to their body. — From sugar to supplements, our experts weigh in on what to eat and what to avoid.

When you’re fighting cancer, you’ll find all kinds of information about how what you eat might affect your treatment and recovery. How can you sort out the facts from the hype? Here, our registered dietitians – who all specialize in cancer care – answer the questions they’re most often asked.

Our Experts

Not all nutritionists are dietitians. While anyone can say he or she is a nutritionist, registered dietitians pass examinations, complete continuing education, comply with an ethical code, and have advanced educations.

Every dietitian at Simmons Cancer Center has a master’s degree and is board-certified in oncology nutrition. As a group, these dietitians, who answered the questions in the accompanying article, work with all cancer diagnoses:

Darienne Hall, M.C.N., RD, CSO, LD
Michelle Hamilton, M.C.N., RD, CSO, LD
Shelli Hardy, M.C.N., RD, CSO, LD
Kelli Oldham, M.S., RD, CSO, LD
Errin Sieling, M.S., RD, LD

What foods can help people with cancer best maintain their health, strength, and energy?

It depends on each person’s diagnosis and treatment plan and any side effects he or she is experiencing. Not getting enough calories or protein can lead to slower recovery times and delays in treatment, so most people need to make sure they are getting enough protein and consuming a variety of foods. In general, a more plant-based diet is often appropriate during therapy. The American Institute for Cancer Research (AICR) recommends:

A diet rich in whole grains, vegetables, fruits, and beans
Limiting foods high in fat, refined starches, or added sugars
Limiting processed meat, and restricting red meat to 12 to 18 ounces per week
Choosing water and unsweetened beverages
Limiting alcohol consumption. For cancer prevention, it’s best not to drink alcohol.

Are there supplements you recommend that people with cancer either add or avoid?: We do not recommend supplements unless we know or suspect a deficiency, which might happen with vitamin D, calcium, or vitamin B-12. Supplement manufacturers do not have to prove that their products are effective, pure, or safe. Some supplements can interfere with chemotherapy or radiation treatments and might increase cancer risk. If you do take vitamins or herbal supplements, let your medical team know.

Does sugar “feed” cancer?

Sugar does not “feed” cancer cells any more than it feeds the other cells in your body. When you eat a lot of sugar, your body produces more insulin, and increased insulin levels are associated with higher cancer risk.

We do not recommend limiting natural sugars in whole foods such as fruit and starchy vegetables, or complex carbohydrates in whole grains and beans. The American Heart Association recommends keeping added sugar below 100 calories per day (about six teaspoons) for women or 150 calories per day (about nine teaspoons) for men.

How much alcohol is OK?: Even small amounts of alcohol pose some cancer risk. The AICR recommends no more than one drink per day for women or two drinks per day for men. Alcohol can increase estrogen levels, so women with hormone-sensitive cancers should consider cutting back to one to two servings per week or less. If you don’t drink, don’t start, and if you do, keep it in moderation.

Do soy foods increase breast cancer risk?: Research has found that one to two servings per day of whole soy foods such as edamame, tofu, or soy milk do not increase breast cancer risk. Whole soy foods are a complete protein source and can be part of a more plant-based diet.

What can help manage nausea?

We recommend:

Consuming small, frequent meals
Limiting exposure to strong food smells
Avoiding foods that can cause heartburn
Focusing on cool, light foods
Trying ginger tea or ginger chews
Using hard candies, gum, or mouthwash to eliminate bad tastes or smells
Sitting upright while eating and avoiding lying down within 30 minutes of eating

What role do antioxidants and phytochemicals play for people with cancer?: They can help reduce inflammation and support the immune system. Good food choices are fruits, vegetables, legumes,
nuts, seeds, whole grains, fungi, and some herbs and spices. Skip the supplements—their high doses can interfere with some cancer treatments.