Learn few key facts how diet, sleep and physical activity affect your immune system.


A diversified, nutrient-rich diet makes a healthy body including a healthy immune system [1]. Nutrients that have been identified critical for immune functions include vitamin C, vitamin D, zinc, selenium, iron [2-4]. Vitamin C can for example enhance chemotaxis, phagocytosis, generation of reactive oxygen species by neutrophils, and thus ultimately enhance microbial killing. Some food, such as fish oil, containing omega-3 fatty acids exert anti-inflammatory and tissue-protective roles [5]. A balanced, nutrient-rich diet supports our gut microflora by feeding good bacteria and maintaining their healthy colonies. This is important because a healthy gut microbiome plays a key role in supporting good immune functions. 


Modern way of living is very fast and very ambitious. For an average person, a day is often too short to fulfill their busy agendas, commitments, and yet find time to unwind and relax. Often, sleep is the “activity” that needs to be sacrificed, deprioritized in order to provide extra time to finish daily agendas.

Sleep deficiency, however, increases the risk of obesity, diabetes, cardiovascular disease, depression and even an early death. It is thus not surprising that sleep is necessary for optimal immune functioning and impacts immune signaling processes.

Sleep enhances formation of immunological memory as shown in studies of people who received vaccination and slept on the first night following vaccination versus those who stayed awake after receiving a shot. Those who slept after the vaccination displayed higher antibody response than those that stayed awake [6]. Interestingly, cytotoxic NK cells and cytotoxic T lymphocytes (CTLS), peak during the wake period allowing an efficient and fast response to invading pathogens, to which we are more likely exposed to during the active phase of the organism.

Sleep deprivation induce a persistent unspecific production of pro-inflammatory cytokines, known as chronic low-grade inflammation, and lead to immunodeficiency, leading to detrimental effects on  immune homeostasis and health [7].


Robust epidemiological data suggests that regular physical activity whether in a form of a structured exercise or unstructured form of activity reduces the incidence of many chronic diseases, both communicable caused by viral or bacterial infections, and non-communicable such as cancer and chronic inflammatory diseases. Lower rates of upper respiratory tract infections are noted in those engaging in moderate-to-high physical activities comparing to those with low activity levels.

Moderate physical exercise boosts macrophage functions, lymphocyte circulation, immunoglobulin levels and anti-inflammatory cytokines in the blood. These post-exercise immune modulations account for enhanced immunosurveillance when repeated regularly. Yet, important to note, adequate rest periods are an absolute must as without them, strenuous and prolonged physical activity may lead to immunodepression [8].


3. Wessels, I., M. Maywald, and L. Rink, Zinc as a Gatekeeper of Immune Function. Nutrients, 2017. 9(12).

4. Carr, A.C. and S. Maggini, Vitamin C and Immune Function. Nutrients, 2017. 9(11).

5. Sobrino, A., et al., Protective activities of distinct omega-3 enriched oils are linked to their ability to upregulate specialized pro-resolving mediators. PLoS One, 2020. 15(12): p. e0242543.

6. Lange, T., et al., Sleep enhances the human antibody response to hepatitis A vaccination. Psychosom Med, 2003. 65(5): p. 831-5.

7. Besedovsky, L., T. Lange, and J. Born, Sleep and immune function. Pflugers Arch, 2012. 463(1): p. 121-37.

8. Laddu, D.R., et al., Physical activity for immunity protection: Inoculating populations with healthy living medicine in preparation for the next pandemic. Prog Cardiovasc Dis, 2021. 64: p. 102-104.