Even though cancer therapies can sometimes take the pleasure out of eating, treatment is a time when a healthy diet is more important than ever. You may have to get creative about your food choices, but studies and dieticians say that maintaining a healthy weight and getting the nutrients you need to stay strong is worth the effort.
"There is some fairly good research that suggests that making positive dietary and lifestyle changes may have a very positive impact on tolerance to cancer treatments and maybe even positively impact outcome," explains David Grotto, RD, an American Dietetic Association spokesperson and the director of nutrition education at the Block Center for Integrative Cancer Care in Evanston, Illinois.
Cancer Treatment on Nutrition
Because of the anxiety associated with cancer, appetite is sometimes affected even before treatment begins. But being well nourished prior to surgery, and the radiation therapy and/or chemotherapy that may follow it, helps ensure tissues heal as quickly as possible and side effects are easier to withstand.
Good nutrition before and after surgery, which is often the first step in the treatment process, is particularly critical for people with later-stage cancer who may already be experiencing wasting or malnutrition, which increases risk for infection or other treatment complications. "Surgery puts a great deal of stress on the body and recovery can increase the amount of calories and protein the body requires," Grotto says. The amount of calories and protein needed varies from person to person and is based on factors other than wound healing, such as age, weight and the degree to which someone is physically active.
Nutritional challenges due to surgery itself depend upon where in the body the surgery is taking place. For example, surgery for cancer of the head and neck may make chewing and swallowing difficult, which may require a diet with foods of a soft consistency, Grotto says. Cancers of the stomach or intestines or colon may involve the removal of part of the digestive system, which can cause diarrhea or constipation.
As with surgery, the nutritional problems radiation therapy causes depend on what part of the body is being targeted. The beam of radiation that is focused on the area containing the cancer cells may also damage any healthy cells in its path. A woman getting upper chest radiation for breast cancer, for example, might have burning in the esophagus, while radiation to the abdomen can cause stomach irritation, nausea and lactose intolerance. And radiation to the colon, rectum, prostate, ovaries, uterus, cervix and bladder can cause diarrhea.
U.S. & World
Chemotherapy, which involves drugs that travel through the whole body, can interfere with nutrition in a host of ways. In addition to killing rapidly dividing cancer cells throughout the body, chemotherapy drugs also eliminate healthy rapidly dividing cells, such as hair follicles and the cells that the line the digestive tract. That's why hair loss, nausea and vomiting are common side effects. Besides nausea and vomiting, constipation, diarrhea, water retention, mouth sores, fatigue and depression can all influence nutrition and body weight by affecting appetite or one's ability to eat.
Nausea and Loss of Appetite
If nausea has diminished your appetite, or if you have early satiety from upper abdominal surgery, which means you get filled up quickly, eating five or six small meals a day can help. Sometimes nibbling on dry carbohydrate foods such as crackers can help you "eat through" the nausea. Nutritious beverages, such as smoothies, can be a good choice for people having trouble getting solid food down. Grotto recommends adding supplements such as whey protein to smoothies for extra punch.
"Whey protein may help you increase lean muscle tissue," Grotto says. "This is a tremendous benefit because quite often people will have muscle wasting as a side effect of chemotherapy and radiation."
"But whey protein doesn't provide a lot of calories," Grotto continues. "Another supplement that we like to use that is good for calorie boosting is called 'MCT oil,' or medium chain triglyceride oil, which has about 125 calories per tablespoon."
Grotto also recommends adding food sources of omega-3 fatty acids, such as natural peanut butter or almond butter, to your smoothie to boost calories. Dairy products can also contribute calories. For those people who develop lactose intolerance from chemo or radiation to the lower abdomen, alternatives such as soy or rice milk may be a better choice. Some people, however, may need medication that stimulates appetite such as Marinol (dronabinol), which is a derivative of cannabis.
Problems Along the Gastrointestinal (GI) Tract
Liquid nutritional therapy provided by a dietician may also be a good route for people with chemotherapy-related mouth sores or sores along the GI tract, as well those with a sore throat or tongue from other therapies. It might also be a good choice for people who have had treatment for esophageal cancer that has caused the esophagus to contract. The smoothie recipes Grotto gives his patients with mouth or GI sores includes an amino acid supplement called glutamine, which has been shown to repair the lining of the gut. Otherwise, soft, bland foods such as oatmeal, pudding and bananas are helpful.
Surgery, radiation therapy and chemotherapy can all lead to constipation or diarrhea, but fortunately, making dietary changes can help significantly with bowel problems. For example, if you have diarrhea, frequent, small meals are helpful, as are cooked or pureed vegetables. Raw fruits and vegetables, and fried foods should be avoided. Grotto suggests adding carob, a plant-based substance that tastes like chocolate, to smoothies because of its binding effect on the intestines. People are also advised to drink eight glasses of water a day to help prevent dehydration, as well as to drink beverages at room temperature and to avoid carbonated drinks.
People with constipation, on the other hand, should eat more fruits and vegetables and whole grain foods and try to get some exercise. Those with severe symptoms or who are on pain medications that cause constipation may need to add a stool softener or laxative to get back on track.
Weight Gain
Although people usually associate only weight loss with cancer treatment, weight gain is not uncommon. For example, in younger women, chemotherapy can trigger an early menopause that causes a faster version of the muscle tissue loss and fat tissue gain that occurs in postmenopausal women. Also, hormonal therapies such as tamoxifen for breast cancer can cause fluid retention and weight gain.
"Weight gain is a concern because some of the literature out there suggest that weight gain during remission is a poor prognostic indicator for breast cancer patients," Grotto says. (Studies show that, particularly in postmenopausal women, fat cells play a role in estrogen production, possibly increasing risk for breast cancer.) "So we're very aggressive with dietary and exercise intervention during treatment and especially after treatment."
A Healthy Diet
Grotto points out that cancer treatment can actually serve as a good time to see a dietician and make healthy dietary changes that you can sustain over the long term. "If you look at the American Cancer Society and the American Institute for Cancer Research guidelines, they are espousing a more plant-based diet," he says. "We're finding many of our patients who are undergoing chemotherapy lose their appetite for meat anyhow, which makes it a little easier to make that dietary change."
Dieticians advocate that people with cancer consider healthy foods allies that can make the body stronger both during and after treatment. Says Grotto, "I think we're going to see that nutrition is going to play a more and more important role in not only preventing diseases such as cancer, but treating them as well."
