Nutrition & Your Immune Health

Nutrition & Your Immune Health Do embrace a style of eating mostly whole plant foods.

The DOs and DON’Ts of Eating for Immune Support During Cancer

by Lori Bumbaco, MS, RDN, CSO, LDN

One of the most common side effects of cancer and its treatment is a weakened immune system. This can leave cancer survivors with an increased risk for infections. During cancer treatment and recovery, you’ll need to take extra precautions to minimize this risk. One thing you can do to support your immune system is eat a healthy diet.

Nutrition is essential for anyone diagnosed with cancer. In fact, experts and professional organizations recommend that all people diagnosed with cancer be screened for nutritional risk and referred to a registered dietitian for nutrition therapy if needed. One of the many goals of nutrition therapy for cancer survivors is making the most of nutrient intake to support all systems within the body, including the immune system. A registered dietitian can collaborate with you to create a specific nutrition plan to meet your unique needs. 

However, there are some things you can do on your own to improve your nutrition and support your immune system after a cancer diagnosis. Consider these DOs and DON’Ts to help you make informed decisions about nutrition and your immune health.

There is no “one size fits all” approach when it comes to nutrition.

DON’T believe the hype. One of the most frequent questions people with cancer ask is how to leverage nutrition – from special diets to pricey supplements – to support immunity. An overwhelming number of unsubstantiated claims promise “miracle cures” for those with compromised immunity. Not only may these false miracles be potentially dangerous, but they can also be costly, causing undue financial burden and emotional distress. 

DON’T rely on any one single nutrient or food to support your immune function. The immune system is complex. Diets are complex. The concept that any one food or ingredient can fully support your immune system doesn’t take into account the intricate relationship between all the nutrients found in food and your body’s immunity. 

DON’T assume you need to “boost” your immune system. The diet and nutrition industry markets deceiving products that promise instant “immunity boosting” results. While it may be tempting to believe that specific nutrients or foods can enhance your immune system and instantly make you healthier, the goal instead should be to maintain a properly functioning immune system. Our immunity works best when it is not over or under active. In addition, there is no evidence that nutrition can “rev up” your immune system. A helpful strategy to consider when you come across this type of marketing ploy is to say to yourself, “If it sounds too good to be true, it probably is too good to be true.”

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DO embrace a style of eating mostly whole plant foods. As it turns out, the same types of food that have cancer-preventive qualities are the same ones that are needed for a properly functioning immune system. Chances are that you have heard about the plant-based diet trend. It should be noted that oncology dietitians have recommended this way of eating long before it gained its current popularity. While there is no consensus on how to define a plant-based diet, experts do agree that most of the meals and snacks we eat should consist of whole plant foods. This includes whole grains, vegetables, fruits, beans and lentils, and nuts and seeds. Food originating from animals does not have to be eliminated, but these foods should be consumed in smaller quantities compared to plant-based foods. Eating this way saturates your body with an abundance of the nutrients needed to support your immune system.

An overwhelming number of unsubstantiated claims promise “miracle cures” for those with compromised immunity. DON’T believe the hype.

DO seek out specific nutrition guidance for your unique needs. There is no “one size fits all” approach when it comes to nutrition. A registered dietitian can assess your nutrition needs and offer effective nutrition recommendations to meet those needs. Some dietitians are board-certified experts in oncology, which uniquely qualifies them to provide nutritional guidance to cancer survivors. Before attempting to modify your diet, consider requesting a referral to a registered dietitian who can help you through the process. 

DO focus on the big picture. Nutrition is a key player in sustaining immune function, but it is not the only player on the team. The best approach is an integrative one that considers how sleep habits, stress, and physical activity can affect your overall immunity. 

The relationship between nutrition and immunity is a complicated one, and our understanding of it is constantly evolving. In the meantime, sticking to the fundamental basics of healthful eating is a safe bet. However, remember that nutrition is only one piece of the puzzle. Achieving optimal immune function requires a comprehensive lifestyle approach.


Lori Bumbaco is a board-certified specialist in oncology nutrition at Cancer Wellness Center in Northbrook, IL. In addition to individual nutrition counseling, Lori co-facilitates the center’s Weight Loss for Wellness and Mindful Kitchen programs. Lori’s areas of interest include empowering survivors with reputable information, building confidence in the kitchen, and exploring how food is more than just nutrition.

This article was published in Coping® with Cancer magazine, Winter 2023.

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