Getting the nourishing foods you need can help make your treatment and recovery easier—and give your soul a boost, too.
Avocado Egg Salad Sandwiches

Cancer affects many people in the United States and across the world, with almost 2 million new cases expected to be diagnosed in the U.S. in 2022, per the American Cancer Society. Thankfully, significant progress has been made over the years. From 1991 to 2019, there's been a 32% decline in cancer deaths, thanks to advances in early detection.

When patients newly diagnosed with cancer come in to see Hannah Dalpiaz, RD, LDN, CNCS, they've got a lot on their minds. "They're trying to figure out, 'Do I have to change everything?'" says Dalpiaz, who's a senior clinical nutritionist at Dana Farber Cancer Institute/Brigham and Women's Hospital in Boston. 

But most of them, Dalpiaz notes, are eager to talk about what to eat.

"For a lot of people, nutrition is one of those things they can hang onto that feels like they still have control," she says. With cancer, "there are so many unknowns." 

Yet, one clear "known": eating well can make a difference at every step of a cancer journey. For one, many people come into cancer treatment with nutrition problems already, Dalpiaz says. They might have eating challenges due to cancer itself—or the stress and anxieties it causes.

It's also true that a well-nourished body is better able to handle the ups and downs of treatment and finish treatments without delays.  

Good nutrition, says Dalpiaz, can "help patients have the best quality of life during treatment, have more energy, feel better and reduce complications of treatment." In fact, a 2018 article in the British Journal of Nutrition stated that nutritional factors, including what you eat, can significantly impact the outcome of a cancer diagnosis.

If you are being treated for cancer, or if a loved one is, here are some tips about what to expect—and how you can keep yourself nourished and feeling your best.

How Do Cancer and Treatment Affect Your Eating?

Chemotherapy and radiation, the mainstays of many cancer treatments, often cause side effects that can make eating challenging. "A lot of cancer treatments target the cells in the body that turn over the most quickly," explains Dalpiaz. "And the lining of the mouth, stomach and small intestine also have cells that turn over quickly—so they get pulled into the mix of what's targeted, too." That's why symptoms like mouth sores, nausea, vomiting and digestive issues such as diarrhea and constipation are some of the most common issues patients face.

Some people—especially those being treated for head and neck cancers, might experience changes in their sense of taste, develop a dry mouth or have trouble swallowing.  

And just being treated for cancer can simply make you tired—maybe too tired to eat on some days.

Additionally, according to the American Cancer Society, people living with cancer can experience not feeling hungry and unexplained weight loss or gain, both of which affect their nutritional state. Even more so, a 2021 report published in Frontiers in Nutrition noted that 40% to 80% of people with cancer can face malnutrition during the course of their illness.

Tips to Overcome Eating Challenges 

Luckily, Dalpiaz has lots of tools in her toolbox to help patients with eating problems. She'll often recommend eating smaller, more frequent meals—easier to manage when appetite and energy levels are low. This can also help prevent nausea, she explains, as the acid in an empty stomach can trigger a "vicious cycle of feeling more nauseous."  

If you're having trouble swallowing, softer foods like soups, fruits and well-cooked vegetables and pasta can help. With mouth sores, try smooth-textured foods like avocado, peanut butter, hummus or smoothies, and avoid acidic, sour or spicy foods if they feel irritating in the mouth or throat. "Cool temperatures can also feel soothing," says Dalpiaz. 

Getting some fiber-rich foods like fruits and vegetables into your meals can help manage constipation—and if diarrhea is an issue, stick to small amounts of foods that are easy on your stomach, like plain crackers, rice or cottage cheese. Be sure to drink plenty of fluids to prevent dehydration and keep things moving along in your gut. 

If you're experiencing taste changes, keep an open mind, Dalpiaz recommends. Experiment with new dishes, flavors and sauces; you might find you like something you didn't like before. Try different temperatures or textures to enhance the eating experience. "Work with the new normal … and know that what didn't work today might look totally different two weeks from now." 

Above all, don't stress that what you're eating isn't nutritionally balanced and perfect, Dalpiaz adds. "At different times during treatment, nourishing the body might look very different from what we think a 'healthy meal' looks like … it might just be a couple of crackers with peanut butter."

Foods to Include during Your Cancer Treatments

Getting enough protein before, during and after cancer treatment is important to help your body repair damaged cells and prevent muscle loss, so try to get in the habit of including some protein at every meal. Top your morning toast with peanut butter, add cooked chicken or beans to your soups or salads, snack on hard-boiled eggs, hummus or Greek yogurt—or whirl some tofu into a fruit smoothie. 

Dalpiaz also recommends aiming to "eat a rainbow of colorful fruits and vegetables," to get the benefits of cancer-fighting phytonutrients—and a 2020 report from the Nurses' Health Studies at Harvard T.H. Chan School of Public Health published in Cancer Research may bear up that recommendation. The researchers followed the diets of almost 9,000 women with breast cancer for up to 30 years. Not surprisingly, they found that those who ate the highest amounts of vegetables, specifically leafy greens and cruciferous veggies, after their cancer diagnosis had a higher survival rate than those who ate lower amounts.

Foods to Limit during Your Cancer Treatments

"Big picture, there isn't any one food that should be off-limits during cancer treatment," says Dalpiaz. "It really depends on what symptoms you're experiencing."  That said, she steers her patients toward limiting red meats and processed meats, which have been associated with higher rates of colorectal cancers. The American Institute for Cancer Research recommends eating no more than three portions (12 to 18 ounces total cooked weight) of red meat per week, and eating little, if any, processed meat.

And, while Dalpiaz believes widespread "sugar feeds cancer" fears are a "gross oversimplification," she recommends staying within the guidelines recommended by the American Heart Association: no more than 9 teaspoons (36 grams) per day for males, and 6 teaspoons (25 grams) for females. The rationale: Too many added sugars can lead to weight gain, which ups cancer risk. 

The Bottom Line

Eating well throughout cancer treatment can be a challenge, but the creative solutions are many. Working with a dietitian can help you make those small shifts that can make a big impact on your health and help you retain a sense of normal life, says Dalpiaz: "The goal is to find ways to make eating enjoyable, in a healthful way that helps you feel your best."