The Best Foods to Eat if You Have Cancer

A nutritious diet is important for everyone but especially vital for people with cancer. Eating a nutrient-rich diet is linked to boosting the immune system, potentially helping people with cancer fight the disease and prevent infections more effectively.

What's more, getting proper nutrition can help reduce chemotherapy and other cancer treatments' side effects, such as nausea, weight loss and vomiting.

In general, the recommended food pattern for people with cancer and those who survived cancer is one that includes fruits, vegetables, whole grains, beans and protein-rich foods. And after cancer treatment, you'll want to closely follow a nutritious food plan to optimize your long-term health.

Read more: What to Eat to Boost Your Immune System During Chemo

A healthy diet includes fruits and vegetables, and these foods are particularly important for anyone with cancer. The reason for their benefit extends beyond the fact these foods are packed with vitamins and minerals. Fruits and vegetables are also rich sources of phytochemicals, substances that provide plants with their color, odor, flavor and many health benefits, according to the American Institute for Cancer Research.

Phytochemicals are a plant's protection from drought, predators and disease — and these powerful antioxidants are linked to reducing inflammation, improving immune function and reducing our cancer risk, according to a June 2015 report in British Journal of Medical Practitioners. An easy way to ensure you're getting phytochemicals is to include a variety of colorful fruits and vegetables daily, such as:

• Purple, blue and red produce including blueberries, raspberries, blackberries, plums, beets, tomatoes, watermelon, cherries and apples.
• Orange and yellow options such as cantaloupe, carrots, yams, mango, oranges and peaches.
• Green fruits and vegetables including collard greens, spinach, kale, asparagus, green beans, kiwi and avocado.
• White and brown choices including mushrooms, garlic, onion, potatoes, jicama and cauliflower.

For cancer prevention and to reduce the risk of recurrence, aim to eat at least 2.5 cups of fruits and vegetables daily, per the American Cancer Society's (ACS) guidelines, published in the January 2012 issue of CA: A Cancer Journal for Clinicians.

While there isn't much research on how specific foods offer protection against different types of cancer, whole grains are usually associated with cancer-protective benefits.

Indeed, a review of 117 studies involving over 200,000 people who survived cancer linked improved survival rates in people who closely followed a high-quality diet, which was characterized by eating whole grains, fruits, vegetables, legumes and nuts as well as a low intake of meat, per the December 2016 study in Nutrients.

Whole grains are cereal grains that have not been processed to remove the bran and germ — which is where most fiber and phytochemicals are located. Whole grain options include:

• Oatmeal
• Bulgur (cracked wheat)
• Brown, black or wild rice
• Whole cornmeal
• Whole wheat bread
• Barley
• Quinoa

Read more: 19 High-Fiber Foods — Some May Surprise You!

The U.S. Dietary Guidelines recommend that whole grains make up at least half of grain choices in a healthy diet. So don't feel guilty if you eat some refined grains, such as white toast or cream of wheat cereal, particularly during cancer treatment when you likely need to eat more calories or eat what you can tolerate. If you have concerns about how to eat during treatment, ask your oncology dietitian.

The U.S. Dietary Guidelines also recommend protein-rich foods, such as the ones below, as part of a healthy diet.

• Fish
• Beans, lentils and peas
• Chicken and turkey
• Lean meat
• Nuts, seeds and peanut butter
• Eggs
• Soy products including tofu, edamame and soy milk
• Milk, yogurt and cheese

According to the ACS, our bodies need protein to build and repair tissue and to foster a healthy immune system. Most healthy people can easily meet their protein needs through their diets, but people undergoing cancer treatment may need more protein.

During treatment, protein needs can be met by eating any high-protein foods you can tolerate but aim for lean, low-fat choices. For a long-term eating plan that reduces cancer risk, the January 2012 ACS report recommends limiting red meat and processed meat, such as bacon or sausage, and focusing on plant-based proteins, such as beans, nuts, seeds and soy.

Read more: What Are the Calorie and Protein Requirements for People With Cancer?

While dietary fats provide energy and necessary nutrients, most people can easily meet their calorie and nutrient needs through a varied diet that limits fats and oils. However, if you're undergoing cancer treatment and need to boost your calorie intake, adding some sources of healthy fats will help. According to the Academy of Nutrition and Dietetics, sources of healthy fats include:

• Fatty fish, such as salmon, lake trout and sardines
• Nuts, including walnuts, almonds and pistachios
• Seeds, such as ground flaxseeds, hemp and chia seeds
• Avocado
• Peanut butter or other nut butters
• Olive or canola oil

According to the ACS's nutrition and physical activity guidelines for cancer survivors, obesity is related to an increased risk of certain cancers, such as breast cancer, per the April 2012 researched published in CA: A Cancer Journal for Clinicians.

Consequently, people who survived cancer and are overweight may benefit from losing weight and limiting unhealthy fats, added sugars, sugar-sweetened beverages, snack chips and desserts. Seek the advice of a dietitian for an individualized weight loss plan.

If you are undergoing cancer treatment or have been told your immune system is suppressed by your doctor, then take steps to avoid getting sick from foods that have not been prepared, handled or stored properly.

• Keep hot foods above 140 degrees Fahrenheit, and keep cold, refrigerated foods below 40 degrees, according to the ACS. And limit the time perishable or cooked foods spend outside of these temperature ranges.
• Wash fruits and vegetables well.
• Take care to ensure that the utensils or cutting boards used to prepare raw meat, chicken or fish are washed with hot, soapy water before using them for other foods.
• Avoid eating uncooked or undercooked meat, poultry or seafood.

If you do an online search on how to eat with cancer, you'll probably get bombarded with advice. You may read that you have to eat organic, go vegan, follow keto, avoid all sugar and avoid anything processed. This advice can be overwhelming and confusing, particularly if you're facing cancer treatment.

So before you make decisions about changing your diet, learn about your treatment plan and potential side effects — and speak to your doctor or dietitian about a plan that's right for you.

While treatment of early-stage cancers may not impair the ability to eat well, the side effects of chemo, radiation or surgery can get in the way of getting enough food and fluids. According to the National Cancer Institute, treatment side effects may include a poor appetite, taste changes, nausea, mouth sores and impaired digestion or food absorption. And to counter these, you'll need to focus on eating well enough to keep your energy level up, manage treatment side effects and avoid weight loss.

Eating poorly before or during treatment is something to take seriously, as inadequate nutrition can lead to dehydration, loss of muscle or lean body tissue and serious nutritional deficiencies. And the consequences of this can be severe, according to a report in the October 2017 issue of Clinical Nutrition, as malnutrition can impair immunity and weaken the response to cancer treatment.

Read more: A Tasty Diet to Raise a Chemo Patient's Blood Count