Nutrition supports your immune system to help fight infections

COVID-19 and Nutrition: Care for Yourself and Others With These Tips

Learn about: How your body fights infection | Healthy options for chronic conditions | General guidance for maintaining a balanced diet | Immune support shopping list


Taking care of your health in the midst of COVID-19 is on everyone’s minds these days. COVID-19 is the disease caused by an infection from the virus SARS CoV-2. Whether we’ll be exposed ourselves, or have loved ones who are exposed, chances are we’ll all be affected by this in some way.

One way to keep your immune system strong? Maintaining a balanced diet.

Those who have COVID-19 often have respiratory symptoms, such as cough, difficulty breathing, and shortness of breath. As with all viral infections, from the common cold to the flu to COVID-19, adequate nutrition is essential to support your body’s immune system and aid recovery.

Poor nutrition can compromise your immune function and increase your risk of getting infected. Nutrition is crucial for the delivery of energy sources, known as macronutrients, and for support of essential bodily processes provided in part by micronutrients. Both macro and micronutrients are key drivers for a healthy immune response, particularly for higher risk populations.

How your body fights infection

When the body is fighting infection, it does so in three phases: the acute phase, the stable phase, and the recovery phase. Your energy needs change depending on each phase and your nutritional status prior to illness. The acute phase starts with hypermetabolism, typically marked by a fever, which leads your body to turn off your appetite and start to feel fatigued. This essentially feels like your body is going into hibernation mode. All circulating and primary energy sources are grabbed, and once your body’s used up its long-term glucose stores (otherwise known as glycogen), lean muscle mass is pulled from next. This energy grab from lean body tissue without proper nutrition support can lead to decreased gut barrier function (where the majority of our immunity thrives) and immunosuppression, which further complicates healing.

So what are your caloric and protein needs during this hypermetabolic state? There’s evidence to suggest that doubling calories isn’t necessarily the answer during the acute phase if you’re a healthy adult. But if a person is likely malnourished, which describes a significant portion of the population over 65, more calories may be warranted. For the healthy adult, the recovery phase is when your body requires the highest caloric amount, which may be even 30-50% more than your body’s basal metabolic rate (or how many calories your body needs to function normally). Protein intake remains important through all phases during an illness to protect your body against using your muscle stores for energy.

Healthy options for chronic conditions

Although there’s not one magic food to eat for those with chronic conditions, or anyone for that matter, overall supportive nutrition is crucial. Here are some tips to keep in mind for anyone with a chronic condition.

For the purposes of this article, chronic conditions considered include diabetes, high blood pressure, heart disease, and lung disease. These groups, and those who are 65+ years old, are especially vulnerable to becoming ill from COVID-19 and have a higher likelihood for serious symptoms.

A key tip to remember before diving in: people with chronic conditions may have poor appetites to begin with, so eating what they’re able to tolerate is better than adhering to a strict regimen. When it comes to nutrition, people with these chronic conditions at baseline have certain dietary needs and may follow particular guidelines. For these populations, recovery can be more of a serious issue because the highest rates of malnutrition tend to fall with adults 65+, and according to the CDC, 85% of older adults have at least one chronic health condition, and 60% have at least two.

Meal replacement supplements can be a good idea for those who need additional support with getting appropriate nutrition. If you’re thinking about a meal replacement supplement for your family member or someone with a chronic condition, it’s always a good idea to reach out to a registered dietitian or a physician for further guidance.

An additional mention for those with diabetes: it’s important to regularly check and maintain consistent blood sugar levels—both to avoid a spike and a drop. Aim for meals that have both protein and carbohydrates as a pair to avoid blood sugar spikes, as elevated blood sugar levels may prevent timely healing.

And if you are experiencing a blood sugar drop, make sure to have glucose tablets readily accessible, juice or hard candies. Be sure to follow what the American Diabetes Association calls the “15-15 rule” and have 15 grams of carbohydrate to raise your blood sugar and check it after 15 minutes. If it’s still below 70 mg/dL, have another serving. Once you’re back at 70 mg/dL, it’s advised to have a meal to keep your levels stable.

For those with a history of lung disease, choose modest amounts of carbohydrates, and add in more healthy fats. Those with breathing problems, like a previous diagnosis of COPD, may benefit from a diet with fewer carbohydrates (e.g., breads, cereals, and pasta) and more fat (e.g., olive oil, fatty fish, and nut butter) which may help make breathing a little easier.

General guidance for maintaining a balanced diet

In general, protein, carbohydrates, and fat all play an important role in nutritional balance. But more specifically certain foods like lean proteins, fruits, and vegetables may be important to target when optimizing your diet for healing or infection prevention. The protein needs for those at highest risk are already greater due to their history of chronic illness or age. In order to protect and support lean muscle mass, choose lean protein sources such as chicken, turkey, seafood, or plant-based options like beans, nuts, or nut butter, and legumes. Curious about protein supplements or meal replacement supplements? Check in with a registered dietitian or healthcare provider about which brand is ideal.

Eat fruits and veggies

Fruits and vegetables, particularly citrus fruits and leafy greens, provide a steady stream of vitamins A and C, while nuts, seeds, and vegetable oils are rich in vitamin E, dairy products, eggs, and seafood are good sources for vitamin D. Zinc is also important, which is rich in food sources like meat and nuts. All of these are vitamins and minerals known to provide immune support.

With 70% of immunity being in the gut, it’s also good to keep your healthy bacteria thriving. Probiotic sources, such as yogurt and kefir, help keep healthy bacteria thriving and supporting your immune system.

Eat smaller meals more frequently

Another great strategy to keep your immune system strong is starting meals early in the day to maximize caloric intake for healing and aiming for around 4-6 small meals per day. For those with serious respiratory symptoms, eating smaller meals may help prevent early satiety (getting full too quickly) and in turn take stress off the diaphragm, which can allow for easier breathing. Eating frequent meals may also help diabetics who are trying to maintain glycemic control while they’re sick.

Drink plenty of fluids

Be sure to stay hydrated. Not only is this good overall for fighting infection, but it also helps keep mucus thin and easier to remove from the body. In general, drink 6 to 8 glasses of water a day, 8 oz. per glass, unless you’re on a fluid restriction by your physician. Foods like soups, fruits, and vegetables with high water content, such as melon and cucumber, also count as fluid sources. Unsure if you’re getting enough fluids? One way to tell is by your urine. If you’re well hydrated, your urine should be a light color.

The major take-home message for everyone, whether you’re among the high-risk populations or managing a chronic condition, is while it’s important to do your best to eat foods that represent each nutrient, food group, vitamin, and mineral, the ultimate goal is to be sure to have nutritional intake, period. If you’re not hungry or you’re caring for someone who isn’t, don’t force it. Try again at a later time. Choose wisely and try to avoid refined sugar, empty calories, and alcohol intake. Remember, there’s a lot you can do when it comes to your health.


Immune support shopping list (arranged with concentration, affordability, and availability in mind)

Top 10 vitamin A rich foods

  • Beef liver
  • Sweet potato
  • Spinach
  • Carrots
  • Ricotta cheese
  • Cantaloupe
  • Red peppers
  • Mango
  • Eggs
  • Black-eyed peas

(Source)


Top 10 vitamin C rich foods

  • Red pepper
  • Orange
  • Kiwi
  • Broccoli
  • Strawberries
  • Brussels sprouts
  • Grapefruit
  • Cantaloupe
  • Cabbage
  • Cauliflower

(Source)


Top 10 vitamin D rich foods

  • Tuna fish
  • Mushrooms (exposed to UV light)
  • Milk (including Vitamin D fortified non-dairy milk options)
  • Eggs
  • Yogurt
  • Ready-to-eat cereals (whole grain cereals)
  • Orange juice (fortified and 100% juice)
  • Salmon
  • Sardines
  • Cod Liver oil

(Source)


Top 10 vitamin E rich foods

  • Sunflower seeds
  • Almonds
  • Hazelnuts
  • Peanut butter
  • Peanuts
  • Spinach
  • Wheat germ
  • Sunflower oil
  • Safflower oil
  • Tomato

(Source)


Top 10 food sources of zinc

  • Beef chuck roast
  • Beef patty
  • Pork chop
  • Beans
  • Chicken
  • Pumpkin seeds
  • Yogurt
  • Chickpeas
  • Lentils
  • Cashews

(Source)


Standard “feel-better” foods for when you feel unwell

  • Banana
  • Applesauce, unsweetened
  • Whole wheat toast
  • Brown rice
  • Whole fruit popsicles
  • Peppermint, ginger, or herbal tea
  • Bone broth
  • Yogurt (Greek is higher in protein)
  • Ginger chews
  • Oatmeal or Cream of Wheat
  • Honey
  • Yogurt (Greek is highest in protein)
  • Smoothies - make your own! (e.g. ½ cup plain or vanilla Greek yogurt, 1 cup strawberries, 1¼ cup coconut water, ½ banana, honey to taste)

Want to help your immune system further?

Vitamin D plays a role in immune function, so consider checking your current vitamin D levels with our at-home Vitamin D Test.


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References

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5. 2016 Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient. URL. JPEN 2016 Vol 40, Issue 2, pp. 159 - 211.

6. Wintergerst ES, Maggini S, Hornig DH. Immune-enhancing role of vitamin C and zinc and effect on clinical conditions. Ann Nutr Metab. 2006;50(2):85–94. doi:10.1159/000090495

7. Erkelens MN, Mebius RE. Retinoic Acid and Immune Homeostasis: A Balancing Act. Trends Immunol. 2017;38(3):168–180. doi:10.1016/j.it.2016.12.006

8. Cantorna MT, Snyder L, Arora J. Vitamin A and vitamin D regulate the microbial complexity, barrier function, and the mucosal immune responses to ensure intestinal homeostasis. Crit Rev Biochem Mol Biol. 2019;54(2):184–192. doi:10.1080/10409238.2019.1611734

9. Lee GY, Han SN. The Role of Vitamin E in Immunity. Nutrients. 2018;10(11):1614. doi:10.3390/nu10111614

10. Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017;9(11):1211. doi:10.3390/nu9111211

11. Healthy Aging Facts. URL. National Council on Aging.

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