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Supporting Your Immune System

Disclaimer: The information on this page is general in nature for cancer patients and their families. It is not specific to coronavirus (COVID-19).

Visit The Leukemia & Lymphoma Society (LLS)’s Coronavirus Resources page for information specific to COVID-19. Or, read our COVID-19 blog posts.

Your body’s ability to fight infection and disease depends on your immune system. The immune system is made up of cells, tissues, and organs that work together to protect your body from illness and infection.

Since the immune system is not just a single entity, there also isn’t a single food that you can eat or add to your diet to better support your immune system, especially not overnight. The best way to keep your immune system running smoothly is to follow healthy-living strategies.


Good nutrition is important to supporting a healthy immune system. Follow a plant-based, heart-healthy menu that incorporates a variety of vegetables and fruits, whole grains, lean protein, and healthy fats. Eat small, frequent meals throughout the day to stay energized and to ensure your body is getting enough calories, proteins, and nutrients.

Key Nutrients

Including a balance of the following nutrients in your menus over time will best support your immune system:



Food Sources

Protein Protein acts as a “builder.” The body uses protein to build and repair tissues and to make hormones and enzymes that promote the body’s daily functions and supports a healthy immune system. Meats, poultry, fish, eggs, dairy products, beans, nuts, seeds, and soy


You can also add protein to your meals and beverages with a protein powder or nutrition supplement drinks.

Vitamin A Supports normal vision, the immune system, reproduction, and healthy organ function Organ meats, salmon, leafy greens, sweet potatoes, carrots, broccoli, squash, cantaloupe, apricots, mangos, dairy, and fortified cereals
Vitamin B6 Supports the body’s metabolism, the chemical changes that produce energy Poultry, fish, organ meats, potatoes, and fruits (other than citrus)
Vitamin C Supports the immune system, wound healing, and acts as an antioxidant to protect cells Citrus fruits (oranges, tangerines, grapefruit), tomato juice, broccoli, cantaloupes, and strawberries
Vitamin D Allows the body to absorb calcium for strong bones Fortified products such as dairy, orange juice and cereals
Vitamin E Acts as an antioxidant to protect cells from damage, supports the immune system, and widens blood vessels to prevent blood clots Vegetable oils, nuts, peanut butter, and fortified cereals
Fiber Supports bowel regularity, stabilizes blood sugar, and rids the body of toxins in the gastrointestinal tract Whole grains, beans, peas, and lentils
Folate/folic acid Helps create and repair cells’ DNA in the body Leafy green vegetables, asparagus, Brussels sprouts, beans, peas, oranges, and fortified whole grains
Iron Supports blood production Lean beef, seafood and poultry, beans, spinach, nuts, and iron-fortified cereals and breads
Selenium Supports thyroid gland function, DNA production, and the immune system Seafood, meat, poultry, eggs, dairy, and whole grains
Zinc Supports the immune system and cell creation and helps wounds heal Oysters, red meat , poultry, seafood, fortified cereals

Source: National Institutes of Health’s Office of Dietary Supplements

Beware of “Immune-Boosting” Supplements

In any health-food or grocery store, you can find bottles of pills or herbs that supposedly “boost” your immune system. These claims are not approved by the Food and Drug Administration (FDA). The supplements are not only potentially ineffective, but they could also interfere with other medications or treatments. Do not start taking any new supplement or medications without talking to your healthcare team first.

Choose Food First

Choose foods first as your source of vitamins and nutrients. Unless your healthcare team directs you to take a vitamin or supplement, you likely do not need one. The best way to include these nutrients is by eating whole foods.


Fruits, vegetables, and other plants contain a naturally occurring compound known as phytochemicals (or phytonutrients). Phytochemicals refer to a variety of compounds that give fruits and vegetables their color and flavor. Studies show that phytochemicals support the:

  • Immune system
  • Creation of healthy cells
  • Death of damaged cells (such as cancer cells).

Phytochemicals also act as antioxidants to protect the body from damage.

Eating a variety of fruits, vegetables, whole grain, and beans in a variety of colors is the best way to add phytochemicals to your menus. Visit The American Institute for Cancer Research to learn more about different types of phytochemicals and the best food sources for each.


Probiotics aid in digestion and support immunity. Probiotics are the good bacteria like those naturally found in your gut or intestinal tract. Food sources of probiotics include:

  • Yogurt
  • Kefir
  • Kimchi
  • Sauerkraut
  • Miso soup
  • Sour pickles
  • Tempeh
  • Milk with probiotics (buttermilk and sweet acidophilus).

Speak with a registered dietitian or your healthcare team before adding food sources of probiotics to your menus. Some of these foods may not be safe to eat if you are following a low-microbial or low-bacteria diet.

In some cases, your body may need more probiotics than you can get from food. Ask your healthcare team if a probiotic supplement would be beneficial for you. However, your healthcare team may advise you to avoid probiotic supplements if you are immunosuppressed.

Decrease your risk for malnutrition.

People who are malnourished tend to be more susceptible to illness and infection. It can also be harder for a malnourished body to fight off an illness or infection if one is contracted. Malnutrition results when the body does not receive enough calories and/or nutrients to promote good health and sustain healthy functioning of your body’s systems.

Due to the side effects of cancer and treatment, cancer patients are often at risk for malnutrition. Malnutrition can lead to interruptions in treatment schedules, longer recovery times and, in serious cases, death.

Talk to your healthcare team if you notice any of the following signs of malnutrition:

  • Weight loss of 5-10 lbs. without trying
  • Decreased appetite
  • Side effects that make eating difficult or unpleasant.

Follow these tips to reduce your risk of malnutrition during cancer treatment:

  • Do not drastically change the way you eat by eliminating whole food groups or starting a diet to lose weight.
  • Report any unintentional weight loss to your healthcare team.
  • Work with your healthcare team to manage side effects that make eating difficult such as nausea, vomiting, diarrhea, decreased appetite, etc.
  • Eat regularly through the day, every 4-6 hours. Even if you do not feel hungry, try to have a snack or mini meal. If you forget to eat, try setting a timer.
  • Include a protein source with every meal and snack.

LLS Health ManagerTM App. With LLS Health ManagerTM, you can now use your phone to manage your daily health by tracking side effects, medication, food and hydration, questions for the doctor, grocery lists and more. You can also set up reminders to take medications and to eat/drink throughout the day. Learn more and download the app. 


In addition to using nutrition to support your immune system, you can also make changes to your lifestyle to help support health and immunity.

Decrease your exposure to bacteria, viruses, and germs.

The following are tips to decrease your risk of infection and illness:

  • Wash your hands regularly, especially after using the restroom, before and after handling food, and after coughing or sneezing. Wash your hands with clean, running water and soap, scrubbing for at least 20 seconds. You can also use hand sanitizing gels or foams when you do not have access to a sink. Learn more about When and How to Wash Your Hands from the Centers for Disease Control and Prevention (CDC).
  • Practice good food safety to prevent foodborne illness. Food safety is especially important for cancer patients in active treatment who may have a weakened immune system. Visit the Food Safety page to learn more.
  • Keep your home clean to lower the risk of infection.
  • Practice good hygiene and personal care by taking care of your skin, hair, nails, mouth, and teeth.
  • Avoid others who are sick. If you are immunocompromised, avoid crowds of people.
  • If you are immunocompromised, talk to your doctor about whether wearing a mask is helpful for you in some situations.
  • If you have a cut or scrape, keep it clean and dry to prevent infection.

Get enough sleep.

Sleep is an important aspect of health. Our bodies need sleep to recharge and heal. The Centers for Disease Control and Prevention (CDC) recommends that adults get 7 hours or more of sleep every night. If you have difficulty sleeping, try the tips and strategies on the Tips for Managing Insomnia or Difficulty Sleeping page and talk to your healthcare team.

In addition to sleeping enough at night, as a cancer patient, you may need to rest more throughout the day. Try to work in a 30 minute nap. Ask your friends and family to help with chores to allow you more time to rest. Your loved ones probably want to help but may not know how, so suggest specific tasks.

Minimize stress.

Stress can also take a toll on the immune system. In many ways, mental health can also affect your physical health. Try to reduce stress by taking time to do things you enjoy such as spending time with family, spending time outdoors, or reading. If your feelings of anxiety or depression make it difficult for you to complete daily tasks, talk to your healthcare team.

Exercise regularly.

Leading an active lifestyle can also support your immune system by promoting good circulation, which allows the cells and substances of the immune system to move through the body freely and do their job efficiently. Regular exercise promotes good cardiovascular (heart) health, too. The American Institute for Cancer Research (AICR) recommends to get at least 150 minutes of moderate activity or 75 minutes of vigorous, physical activity a week. Physical activity includes walking, jogging, swimming, biking, playing sports, etc. Include strength training and stretching along with aerobic exercise to build muscle and increase flexibility.

Talk to your healthcare team before beginning any exercise plan. You may need to work up to a 150 minutes per week goal or set a goal adjusted for your needs. 

Avoid alcohol and all tobacco products.

For cancer prevention, the American Institute for Cancer Research recommends not to drink alcohol. However, other studies suggest that modest amounts of alcohol may have a protective effect on heart disease and type 2 diabetes. If you do choose to drink, limit consumption to no more than one drink per day for women and two drinks for men. One drink is defined as 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor.

Smoking increases the risk for a number of cancers including lung, oral, throat, esophageal, colorectal, and more. Smoking also increases the risk of other diseases such as heart disease. Read more about the benefits of quitting smoking and how to quit on the Smoking Cessation page.

Download the free publication Healthy Behaviors from The Leukemia & Lymphoma Society (LLS) for more healthy lifestyle tips.


Staying up-to-date on immunizations is another important part of a strong immune system. Immunizations help your body build a resistance to specific diseases. Most immunizations work by introducing a small, safe amount of the disease to your immune system. This way if you are ever exposed to the disease, your body’s immune system already knows how to fight it. Most immunizations are vaccines given as a shot or series of shots.

Many people receive one-time immunizations when they are children for diseases such as chickenpox. Some immunizations, such as tetanus shots, need boosters to keep them effective. Other immunizations, such as flu vaccines, need to be received annually.

Ask your healthcare team which immunizations are appropriate for you. Some immunizations are not safe for people who are immunosuppressed. Visit the Immunizations for Cancer Survivors page to learn more.

Immune System Disorders

Immune System Disorders cause abnormally low or high activity of the immune system. When the immune system is overactive, the body damages its own tissues. These are called “autoimmune” diseases. Examples of autoimmune disorders include lupus and inflammatory bowel disease (IBD). When the immune system is underactive, the body is not able to fight off infection and illness. The human immunodeficiency virus (HIV) is an example of this type of immune system disorder.

If you have been diagnosed with an immune system disorder, talk with your healthcare team about how to stay healthy and well and manage your immune disorder.