What's the connection between nutrition and immunity?

Words like “immune system” or “immunity” have been appearing more often in the news with their relevance to the novel disease COVID-19, but how is the immune system relevant for staying healthy? And how can nutrition influence your immunity? The immune system is critical in preventing foreign and harmful substances, or pathogens, from causing infection (Calder, 2020). Pathogens that make it past the body’s defenses will prompt increased cellular activity and metabolism from the immune system to fight this infection (Calder, 2020; Calder et al., 2020). As such, there is interest in understanding how factors that contribute to healthy immune function might help to offset risk of infection by viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19.

To date, there are no universally proven therapies to ward off COVID-19, but maintaining a healthy lifestyle is one measure individuals can generally take to protect from respiratory infections. Following public health guidelines to limit the spread of COVID-19 from the Government of Canada (2020) are of utmost important, including maintaining a physical distance from others, wearing a protective face covering or non-medical mask, washing your hands for a minimum of 20 seconds, and more. However, along with public health measures, getting proper nutrition and adopting healthy behaviours are important to stay healthy during these unprecedented and stressful times.

A nutrient-rich and balanced diet can help to develop and support a healthy and well-functioning immune system. Consuming a variety of vegetables, fruits, protein-rich food and whole grains with a wide range of nutrients for proper immune functioning is important. Other healthy behaviours include reducing the amount of highly processed foods consumed, getting enough sleep, drinking adequate water, getting physical activity (Hutchinson et al. 2020), and minimizing stress, where possible.

Dieticians of Canada offers general advice in helping Canadians navigate nutrition-related content. As they note, at this time, there isn’t a food or supplement approved to treat COVID-19. As research progresses, we can expect to learn more about the role of nutrition and potentially see the emergence of more specific evidence-based nutrition recommendations.

Research on SARS-CoV-2 and COVID-19 is still advancing, but the above general healthy behaviours to support the immune system are tried and true. Stay tuned for more updates on the role of nutrition in COVID-19. Keep well!

References:

Advice for the general public about COVID-19. (2020, June 3). Dieticians of Canada. Retrieved August 10, 2020, from https://www.dietitians.ca/News/2020/Advice-for-the-general-public-about-COVID-19

Calder, P. C. (2020). Nutrition, immunity and COVID-19. BMJ Nutrition, Prevention & Health, 3. https://doi.org/10.1136/bmjnph-2020-000085 

Calder, P. C., Carr, A. C., Gombart, A. F., & Eggersdorder, M. (2020). Optimal nutritional status for a well-functioning immune system is an important factor to protect against viral infections. Nutrients, 12, 1181. https://doi.org/10.3390/nu12041181 

Hutchinson, A., Panahi, S., Basualdo-Hammond, C., Duncan, A., Field, C., & Reza, Z. (2020). COVID-19 and Nutrition. Retrieved 2020, July 20, from https://cns-scn.ca/sites/default/uploads/files/CNS_2020_COVID-19_and_Nutrition_English.pdf

Know the facts about COVID-19. (2020, July 7). Government of Canada. Retrieved July 20, 2020, from https://www.canada.ca/en/public-health/services/publications/diseases-conditions/know-facts-about-coronavirus-disease-covid-19.html