What should I eat and drink?

A colorectal cancer diagnosis often comes along with a tsunami of diet information from well-intentioned family and friends, lifestyle social media pages, and frantic Google searches. You’re probably wondering how to separate the facts from the pseudoscience! So here’s where to start.

First of all, there’s no scientific evidence that any diet or lifestyle changes will cure your cancer, or even significantly affect your treatment. According to guidelines published by the American Society of Clinical Oncology (ASCO), there’s insufficient evidence to recommend eating or avoiding any specific type of diet, such as ketogenic (low-carb) diets, low-fat, functional foods, or fasting diets. There’s no evidence that they improve quality of life, reduce side effects of treatment, or boost treatment outcomes.

When it comes to diet, the important thing is ensuring that you maintain good nutrition. Going through treatment is hard on the body, and it’s important that you’re getting adequate nutrition and hydration to maintain a healthy weight.

While healthy foods are good choices to maximize well-being, there’s absolutely no reason to stress about an occasional pizza night, slice of cake, or glass of wine. Many patients suffer from taste changes and appetite loss due to chemo. Eat what you can, when you can, and let go of guilt. If all you can eat during chemo is saltine crackers, go for it!

If you have any specific questions or concerns about diet, and how to maximize wellness and maintain weight during treatment, ask your oncologist for a referral to your cancer center’s dietician. Diet needs vary from person to person, so see if your cancer center has a nutritionist too.

It’s important to note that this section goes over general diet information that should be secondary to any specific guidance your healthcare team has recommended for you.

Want to explore different foods and the nutrients they provide?

Take a look at the Foodstruct website for more information about nutrition. You can compare the nutritional properties of different foods to help decide which ones fit best with your health goals.

Here are some tips to help your body get the nutrients it needs while going through treatment:

Maintain a healthy weight

Many people going through treatment experience weight loss, and some experience weight gain. First of all, it’s important to be gentle with yourself and realize that your body will experience changes throughout treatment. However, maintaining a healthy weight can improve your quality of life and help you tolerate chemo, radiation and surgery better.

If you are working on your weight, check out this section for more detailed tips and advice.

Eat small meals throughout the day

Many patients experience nausea, appetite loss, and taste changes at some point. Eat what appeals to you, no matter what time it is — breakfast for dinner, or dessert for brunch both sound good! If you are struggling to eat a full meal, try eating several small meals or snacks throughout the day.

Add protein-rich foods

Protein helps your body repair cells and tissues — which is very important for patients undergoing treatment! Protein also helps your body maintain muscle. Make sure to add a good source of protein to every meal, even if it’s just a couple almonds.

Some protein options include: meat, eggs, cheese, tofu, tempeh, nuts, beans, and pulses.

If you are on a low-residue diet, meat, eggs, cheese and soy products may be a good option because they have low fiber content.

Researchers have discovered a correlation between risk of developing colorectal cancer and consuming large amounts of red and processed meats, so you may want to consider eating these foods in moderation. That said, eliminating these foods from your diet will not cure your cancer, and enjoying a steak or some bacon from time to time is not going to make your cancer worse.

Quality of life is important, so it’s never a good idea to completely deprive yourself of foods that you love.

So what’s a low-residue diet?

You may have heard the term “low-residue diet” before. Simply put, a low-residue diet is a diet that puts as few demands on your digestive system as possible. This means eating low-fiber foods, and avoiding skins, seeds, raw vegetables or other things that may be hard for your body to break down. Many people with ostomies follow low-residue diets.

Eat a variety of fruits and vegetables

Fruits and veggies are critical building blocks for a healthy diet and good health in general. Aim for around five servings of vegetables every day, but however much you can eat is good enough.

If you are following a low-residue diet, or have issues digesting raw fruits and veggies, well-cooked, steamed or blended foods can be a good option. A cup of applesauce or a blended butternut squash soup might be gentler on your gut than a big salad.

If you love raw fruits and veggies, and are able to tolerate them, there’s no reason to avoid them based on concerns of contracting a bacterial infection. According to guidelines published by ASCO, diets that exclude raw fruits and vegetables are not recommended for patients in active cancer treatment.

Stay well-hydrated

Chemo can deplete electrolytes, and patients with ileostomies are at higher risk of dehydration — as their colon no longer helps them absorb extra water from their poop! Fluids help your kidneys process chemo drugs, and clear out contrast dye from your system after a scan. Many patients say that good hydration helps with nausea, and most cancer centers in the US offer the option of getting fluids when you get your pump disconnected.

Aim to drink 8 to 10 glasses of water per day. Keep an eye on how many caffeinated drinks you’re consuming, because it can actually dehydrate you if you drink a lot of them. If you are struggling with energy levels, or have an ostomy, it’s a good idea to add electrolytes. Try Pedialyte, or an electrolyte powder in your water.

Sometimes water is difficult to drink while on chemo, so get creative when hydrating. Try milk, broths, or juicy foods like watermelon or cucumber.

Choose healthy fats

Many people grew up thinking fats were bad for you, but that’s not true! Healthy fats are an important part of a well-balanced diet, especially if you are trying to gain or maintain weight. If this is the case, try adding a good source of fat to your meals.

Some examples are avocados, olives, olive oil, nuts and seeds. If you have an ostomy, nut butters may be a better option. If you are following a low-residue diet, you may have to experiment with small amounts of avocados and nut butters, as they are both quite high in fiber.

Add complex carbohydrates

Complex carbohydrates, such as whole grains, beans, and pulses, are a great source of nutrients and fiber. However, they may not be the best choice if you are on a low-residue diet. You may need to experiment a bit if you have issues digesting high-fiber foods.

Consume sugar in moderation

Foods high in sugar often do not have much nutritional value, so it’s never a bad idea to limit the amount that you eat. If you are concerned with your sugar intake, focus on limiting processed or refined sugars.

That said, removing sweets from your diet will not cure your cancer, and enjoying them from time to time is not going to make your cancer worse. Improving your quality of life when going through treatment is important.

Consider non-alcoholic drinks

Excessive alcohol consumption is not good for your general health and well-being, and has been linked to an increased risk of cancer. And chemotherapy drugs can be hard on your organs, so overstressing your liver with alcohol may not be the best idea.

That said, eliminating alcohol from your diet will not cure your cancer, and occasional drink is not going to make it worse. Unless you have been specifically advised by your team to avoid alcohol, don’t worry about having an occasional glass of wine with dinner. But why not try a fun non-alcoholic fruit spritzer or an alcohol-free beer?

Practice good food hygiene

Chemotherapy drugs can lower your white blood cell counts, which puts you at greater risk of developing infections. If your blood counts are low, it’s a good idea to pay extra attention to food safety. Make sure raw fruits and vegetables are washed before eating. Make sure your meat and fish are well-cooked and leftovers are well-heated. Avoid unpasteurized products and anything past its “use by” date. Finally, always wash your hands before eating.

Be willing to adjust your diet

It’s important to understand that cancer (and cancer treatments) can affect your body’s ability to digest certain foods. So go with the flow, and be willing to try new things and adjust your diet as needed.

If you’ve just had surgery, and need to follow a low-residue diet, don’t feel guilty about eating white bread and pasta for dinner. The most important thing is that you give your body the food it needs to recover from surgery.

If you’re really nauseous from chemo, and can only stomach a couple plain crackers, know that that is okay.

If you struggle with finding foods to eat or have problems with bowel function, the dietician at your cancer center can be a great resource. Just ask your oncologist for a referral!

Talk to your team before making major changes

Is your cousin forwarding you links to articles claiming mushroom extracts will cure your cancer? Have you read a Facebook post about a woman taking turmeric tablets for chemo side effects? You may be thinking “Hey, it’s all natural, what can it hurt? Shouldn’t I throw everything that I can at my cancer?”

Well, the fact is that no vitamin or supplement has been proven to cure cancer, and some can even interfere with chemotherapy or other treatments.

However, there may be a time and place in your treatment plan for certain vitamins or supplements. Many patients choose to work with a naturopath or integrative/functional medicine doctor alongside their standard of care treatments. Many say that it has helped them improve their quality of life and better manage their side effects.

It is absolutely critical that you speak to your care team before starting any vitamins or supplements, or before making any radical diet or lifestyle changes. You do not want to do anything that would potentially interfere with your standard-of-care treatments.

Want to learn more about food and cancer?

Take a look at this study in the Journal of Clinical Oncology, which reviews how diet and lifestyle affect cancer reoccurence and mortality in stage III colon cancer patients.

Want to learn more about diet?

Join one of our COLONTOWN support groups:

In the Healthy Habits Highway, we talk about ways to use diet and exercise to maximize wellbeing while going through treatment

Want to join? Fill out the registration form here.

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