Nutrition & Immune Function in Health and Disease

August 9, 2022

The immune system is a complex network of organs, cells and proteins that uses an array of protective mechanisms to defend the body against infection. It also works hard to prevent pathogens from entering the body, such as viruses or bacteria, and creates an immune memory of them so the body has a faster and stronger response the next time you come across it.

There are two main parts of the immune system: innate and adaptive immunity. Innate immunity is the rapid, first-line defense against pathogens. It is managed by the body’s barrier defenses including skin, lining of the mouth and nose, and mucus, and includes myeloid cells from bone marrow and lymphoid cells from white blood cells. Adaptive immunity is the second line of defense and includes a more specific but slower-acting immune response1.

Immune function is impacted by many factors, and a towering body of research has shown that healthy food and lifestyle habits improve immunity. In addition, this can help manage viruses and protect against chronic diseases, illustrating the central role that immunity plays in overall health.

Oxidative Stress and Inflammation
The key to managing oxidative stress is to improve how your body handles it.1 Lifestyle and dietary measures that can provide support with this include exercising regularly, eating a healthful diet rich in fruits and vegetables, and finding other ways to reduce stress (i.e., yoga, meditation, etc.).

Emerging Research About Diet, Immunity and Disease

COVID-19 and Chronic Disease
One of the most important predictors of death and severity of illness from COVID-19 is compromised function of the immune system. Diminished immunity and chronic inflammation go hand-in-hand, as is seen in chronic diseases including cardiovascular disease, diabetes and certain types of cancer.3 Emerging research shows that contracting COVID-19 can in turn be a risk factor for cardiovascular disease.4

Plant-Based Diets
Chronic elevation of inflammation biomarkers such as C-reactive protein (CRP), interleukin 6 (IL-6) and fibrinogen may predict risk of cardiovascular disease, all-cause mortality, type 2 diabetes and some cancers. Evidence suggests that a plant-based diet helps reduce these inflammatory biomarkers.5

Vitamin D
A trend between low serum vitamin D levels and severity of disease and death from COVID-19 in the elderly was discovered through a 2021 systematic review and meta-analysis. Those with vitamin D levels of >30 ng/ml were 1.5 times as likely to test positive when compared to those with adequate vitamin D levels of 30 ng/ml or higher.6

Exercise has important effects on inflammation biomarkers. Pro-inflammatory cytokines IL-6 and IL-1ß increase more with intense exercise than with moderate exercise. Although the results were inconsistent, regular, moderate exercise generally has anti-inflammatory effects while high-intensity exercise with reduced recovery periods leads to dysregulation of the immune system and increased susceptibility to illness.7

Poor sleep, defined by longer awake times and lower asleep times, is associated with greater inflammation, especially in women. This link is stronger in people who already have at least mild levels of systemic inflammation.8

The Anti-Inflammatory Diet
A 2021 systematic review examined the use of anti-inflammatory foods in preventing or treating respiratory viruses such as COVID-19. Food sources of vitamin C, vitamin D, zinc and omega-3 fats – mainly DHA and EPA- as well as turmeric, ginger, garlic, onions and saffron were found to be protective.9 The vegetarian diet, the Mediterranean (MED) diet and the Dietary Approaches to Stop Hypertension (DASH) are three styles of eating studied for their anti-inflammatory effects. A 2021 systematic review of 29 studies suggests that these plant-based diets lowered concentrations of biomarkers for oxidative stress and inflammation – which ultimately support immune function. The Western and fast-food diet was linked to higher concentrations of these biomarkers.10 In a separate review, the MED diet was shown to have the biggest impact on lowering inflammatory biomarkers IL-6, IL-1ß, CRP, IL-8 and tumor necrosis factor alpha (TNF-α).3

Immune Support Superstar Nutrients
Nutrition can help maintain a healthy, competent immune system. Here are some of the vital nutrients that can help support your immunity.


Some of the Functions on Immune Cells and Overall Immunity

Vitamin C
  • Supports the activities of T-cells and improves the activities of antimicrobial, neutrophil and natural killer cells.
  • Increases the production of virus-killing INFs alpha and beta and differentiation and proliferation of T and B lymphocytes.10

  • Essential trace mineral that supports many physical barriers, such as the cells lining organs, to prevent pathogens from entering the body.
  • Improves immune cell activities including natural killer cell activity, T-cell reproduction, antibody production and phagocytosis.10

Vitamin D
  • Enhances adaptive and innate immune responses.
  • Activates regulatory T-cells.10

Omega-3 fatty acids EPA and DHA
  • Provokes gene expression in macrophages.
  • Regulates the production and secretion of cytokines in macrophages.11

How Healthcare Professionals Can Help
Help manage inflammation and improve immunity by addressing “whole-person health and performance” habits with clients.2 Here are a few ways to support clients in strengthening their immune function:

  • Encourage a plant-based diet with a focus on the components of the MED diet, including plenty of fruits and vegetables, whole grains, nuts, seeds and olive oil.
  • Share ways for them to get enough EPA and DHA from fish and algal products.
  • Encourage zinc from fortified cereal, yogurt, cheese, oatmeal, chickpeas, cashews and pumpkin seeds.
  • Examine blood levels of vitamin D, especially for the elderly. To get enough vitamin D choose fortified juice, milk and cereals and supplements when necessary.
  • Suggest regular, moderate exercise. For overall health benefit, do at least 150 to 300 minutes of moderate-intensity activity every week. For intense exercisers, allow adequate recovery time between bouts of exercise.12
  • Discuss ways to improve sleep habits.

Orgain Offers Ways to Support Your Clients’ Health Journeys!

Orgain offers a wide array of nutrient-dense, high-quality products that could help fill nutrient gaps for your patients and clients, which will in turn help support immune health. Orgain’s Organic Nutritional Shake, offered in certified plant-based and grass-fed dairy options, offers 20+ vitamins and minerals that include 25% (or more) of the recommended daily value for Vitamin C, Zinc and Vitamin D, along with a blend of organic fruits and vegetables.

Also, for more education on factors that impact immunity, such as sleep and gut health, tune in these two popular episodes of The Good Clean Nutrition Podcast:

Episode 8: The Connection Between Diet, Sleep & Health with Marie-Pierre St-Onge, PhD, FAHA, CCSH

Listen Now >

Episode 13: Gut Feelings: Dietary Strategies for IBS Management with Will Bulsiewicz, MD, MSCI

Listen Now >

  1. National Library of Medicine. National Center for Biotechnology Information., accessed 6/30/2022.
  2. Vodovotz Y, Barnard N, Hu FB, et al. Prioritized Research for the Prevention, Treatment, and Reversal of Chronic Disease: Recommendations From the Lifestyle Medicine Research Summit. Front Med (Lausanne). 2020 Dec 22;7:585744. doi: 10.3389/fmed.2020.585744. PMID: 33415115; PMCID: PMC7783318.
  3. Koelman L, Egea Rodrigues C, Aleksandrova K. Effects of Dietary Patterns on Biomarkers of Inflammation and Immune Responses: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Adv Nutr. 2022 Feb 1;13(1):101-115. doi: 10.1093/advances/nmab086. PMID: 34607347; PMCID: PMC8803482.
  4. Vinciguerra M, Romiti S, Sangiorgi GM, Rose D, Miraldi F, Greco E. SARS-CoV-2 and Atherosclerosis: Should COVID-19 Be Recognized as a New Predisposing Cardiovascular Risk Factor? J Cardiovasc Dev Dis. 2021 Oct 10;8(10):130. doi: 10.3390/jcdd8100130. PMID: 34677199; PMCID: PMC8539652.
  5. Craddock JC, Neale EP, Peoples GE, Probst YC. Vegetarian-Based Dietary Patterns and their Relation with Inflammatory and Immune Biomarkers: A Systematic Review and Meta-Analysis. Adv Nutr. 2019 May 1;10(3):433-451. doi: 10.1093/advances/nmy103. PMID: 30947338; PMCID: PMC6520040.
  6. Bassatne A, Basbous M, Chakhtoura M, El Zein O, Rahme M, El-Hajj Fuleihan G. The link between COVID-19 and VItamin D (VIVID): A systematic review and meta-analysis. Metabolism. 2021 Jun;119:154753. doi: 10.1016/j.metabol.2021.154753. Epub 2021 Mar 24. PMID: 33774074; PMCID: PMC7989070
  7. Cerqueira É, Marinho DA, Neiva HP, Lourenço O. Inflammatory Effects of High and Moderate Intensity Exercise-A Systematic Review. Front Physiol. 2020 Jan 9;10:1550. doi: 10.3389/fphys.2019.01550. PMID: 31992987; PMCID: PMC6962351
  8. Dzierzewski JM, Donovan EK, Kay DB, Sannes TS, Bradbrook KE. Sleep Inconsistency and Markers of Inflammation. Front Neurol. 2020 Sep 16;11:1042. doi: 10.3389/fneur.2020.01042. PMID: 33041983; PMCID: PMC7525126.
  9. Vahid F, Rahmani D. Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases? A systematic narrative review. Clin Nutr ESPEN. 2021 Jun;43:9-15. doi: 10.1016/j.clnesp.2021.04.009. Epub 2021 Apr 24. PMID: 34024569.
  10. Aleksandrova K, Koelman L, Rodrigues CE. Dietary patterns and biomarkers of oxidative stress and inflammation: A systematic review of observational and intervention studies. Redox Biol. 2021 Jun;42:101869. doi: 10.1016/j.redox.2021.101869. Epub 2021 Jan 22. PMID: 33541846; PMCID: PMC8113044.
  11. Gutiérrez S, Svahn SL, Johansson ME. Effects of Omega-3 Fatty Acids on Immune Cells. Int J Mol Sci. 2019 Oct 11;20(20):5028. doi: 10.3390/ijms20205028. PMID: 31614433; PMCID: PMC6834330.
  12. Physical Activity Guidelines for Americans, 2nd edition. Available at:, accessed 7/3/2022.

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