Five evidence-backed ways to strengthen your immune system


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With COVID-19 at the front of our minds, many of us are taking extra precautions to protect ourselves and our loved ones. One common area of interest is what we can do to improve our immune health.


While there is no quick fix or way to make us immune to novel viruses, we can certainly take actions to strengthen our immune system. Below are five research-backed practices that can help.

Eat a nutritious and diverse diet

Eating a variety of nourishing foods provides our body with the ammunition it needs to fight off disease – something a supplement or “superfood” alone just can’t do. There is a great deal of research on the immunoprotective benefits of vitamins, trace elements, omega-3 fats, and probiotics. Moreover, diets that fall short in these groups can suppress our immunity and lead to an increased risk of infection.

To fuel your immunity, keep the following tips in mind:

Pictured: Quokka's high-protein breakfast parfait with seasonal fruit.

Focus on variety.

Fruits, vegetables, legumes, nuts, lean proteins, dairy, and whole grains all offer unique nutritional benefits to the immune system. An easy way to get sufficient variety in your diet is to "eat the rainbow" by incorporating an array of colorful foods into your meals each day.

Don't fear fat.

Healthy (unsaturated) fats provide many immunoprotective nutrients. Fish, walnuts, chia seeds, and flaxseed provide anti-inflammatory omega-3 fats, and high-quality vegetable oils and avocados are a great source of Vitamin E, an antioxidant.

Incorporate good bacteria.

Probiotics have anti-pathogenic properties that strengthen the immune system. Ingredients like yogurt, sauerkraut, miso, and kimchi are great sources of probiotics.

Get moving

Exercise not only helps with weight management, energy levels, and mood, but also exhibits immune-supporting benefits. Immune cell stimulation, anti-inflammatory effects, and possibly gut-bacteria diversification contribute to its protective effects on our defense system.

Plus, research studies have shown that regular physical activity is linked to reduced risk of communicable disease (e.g., infections like the flu) and non-communicable disease (e.g., chronic diseases like cancer).  Exercise may also reduce age-related decline in immune function – an increasingly important consideration for all of us as we get older.

No need to train for a marathon or join a gym - these small steps can go a long way!

  • Take the stairs instead of the elevator.

  • Plug in headphones and take calls or listen to podcasts while on the move.

  • Schedule a daily walk break.

  • Check out free workout classes on YouTube.

  • Track your daily steps and set weekly goals.

Reduce stress and anxiety

The connection between our mental wellbeing and physical health is no longer theoretical, but backed by evidence-based research. Psychoneuroimmunology, or the study of mental health and immune function, is a growing field of scientific literature.

It is well established that psychological stress activates an immediate immune response, which is a normal and healthy defense mechanism. However, when we remain in a stressed state for prolonged periods due to work, relationships, or other sources of anxiety, it takes a toll on our immune health. These prolonged periods of stress can lead to an increased risk of infection and longer healing times.

Feeling anxious? Consider trying the following techniques to reduce stress and anxiety.

  • Practice mindfulness, or try a meditation app like Headspace, Calm, or Simple Habit.

  • Disconnect to recharge - take a daily break from your computer and phone.

  • Listen to soothing music.

  • Reflect with a daily gratitude journal.

Get outdoors

Studies have found that regular exposure to green space can reduce stress, improve mental health, and enhance our immune function. Contact with nature’s own microbial species may strengthen our defense system, and natural substances emitted by plants and trees may support immune cell activity. Lastly, time spent outdoors (in the sun) improves our vitamin D status, which is linked to a strong immune system.

Working from home? Walking a lap or two around your block between meetings can be a great way to get outdoors and increase your energy levels during the day.


Be sure to practice safe social distancing, and keep in mind your local health department's guidelines regarding use of certain public spaces during the COVID-19 pandemic.

Prioritize your sleep

Sleep offers our body a chance to recover, repair, and reset. Therefore, adequate sleep is pivotal to our immune system. Studies have shown that poor sleep habits can negatively affect immune cell production and function, and lead to increased risk of infection. On the other hand, getting enough sleep has been linked to enhanced immune memory and adaptation.

Try some (or all) of these proven ways to improve your sleep health:

  • Stick to a schedule. Aim for consistent bedtimes and wake times.

  • Remove stimulating triggers like phone screens or work an hour before going to bed.

  • Make your bedroom a sleep-friendly sanctuary - ensure it is cool, dark, and quiet.

  • Cut back on caffeine after lunch.

About the author

Megan Maisano

Megan is a health and wellness professional currently working at the Cleveland Clinic. As a combat veteran, marathoner, and ironman, Megan enjoys researching and communicating the value of nutrition for both physical performance as well as holistic health. She is currently completing her Dietetic Internship at the Cleveland Clinic to become a Registered Dietitian, and is a member of Quokka's nutrition team, where she works with members to help them develop and refine nutrition plans that support their goals.


  1. Wu D, Lewis ED, Pae M, Meydani SN. Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance. Frontiers in Immunology. 2019;9(3160).

  2. Linus Pauling Institute, Oregon State University. Nutrition and the Immune System. Accessed from

  3. Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017;9(11).

  4. Dardenne M. Zinc and immune function. European Journal of Clinical Nutrition. 2002;56(3):S20-S23.

  5. Maggini S, Wintergerst ES, Beveridge S, Hornig DH. Selected vitamins and trace elements support immune function by strengthening epithelial barriers and cellular and humoral immune responses. Br J Nutr. 2007;98 Suppl 1:S29-35.

  6. Campbell JP, Turner JE. Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan. Frontiers in Immunology. 2018;9(648).

  7. Nieman DC, Wentz LM. The compelling link between physical activity and the body's defense system. Journal of Sport and Health Science. 2019;8(3):201-217.

  8. Baek K-W, Jo J-O, Kang Y-J, et al. Exercise training reduces the risk of opportunistic infections after acute exercise and improves cytokine antigen recognition. Pflügers Archiv - European Journal of Physiology. 2020;472(2):235-244.

  9. Brolinson PG, Elliott D. Exercise and the Immune System. Clinics in Sports Medicine. 2007;26(3):311-319.

  10. Littrell J. The mind-body connection: not just a theory anymore. Soc Work Health Care. 2008;46(4):17-37

  11. Nakata A. Psychosocial Job Stress and Immunity: A Systematic Review. In: Yan Q, ed. Psychoneuroimmunology: Methods and Protocols. Totowa, NJ: Humana Press; 2012:39-75.

  12. Morey JN, Boggero IA, Scott AB, Segerstrom SC. Current Directions in Stress and Human Immune Function. Curr Opin Psychol. 2015;5:13-17.

  13. Frumkin H, Bratman GN, Breslow SJ, et al. Nature Contact and Human Health: A Research Agenda. Environmental Health Perspectives. 2017;125(7):075001.

  14. Li Q, Kawada T. Effect of forest environments on human natural killer (NK) activity. Int J Immunopathol Pharmacol. 2011;24(1 Suppl):39s-44s.

  15. Besedovsky L, Lange T, Born J. Sleep and immune function. Pflugers Arch. 2012;463(1):121-137.

  16. Besedovsky L, Lange T, Haack M. The Sleep-Immune Crosstalk in Health and Disease. Physiological Reviews. 2019;99(3):1325-1380.


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