STAYING STRONG WITH IMMUNE SUPPORTING NUTRITION
According to the CDC, the 2025-2026 influenza season is projected to be severe, with around 15 million illnesses reported so far. The culprit is the influenza strain A(H3N2), responsible for over 90% of this season’s flu cases. Even among individuals who received the flu shot, this strain has the ability to evade some of the flu vaccine’s protections, with early reports showing 30-40% effectiveness this season.
So what can you do to support your immunity this season? This blog will cover what happens when you get sick, and how nutrition can support the immune system.
The immune system is a network that includes organs, white blood cells, proteins, and chemicals that work together to protect from harmful pathogens, heal from injuries and infections. When we get sick, the immune system is triggered and begins creating antibodies and signaling molecules to attack the virus. The immune response triggers inflammation which is what causes symptoms like chills, muscle and joint aches, and overall feelings of fatigue. The immune system creates new immune cells, antibodies, and chemical messengers to eliminate the virus and return the body to neutral. This process requires energy, nutrients, and rest.
Nutrition has a profound impact on human health, and research has identified that the consumption of specific nutrients can support immune health. Certain foods cannot “boost” the immune system, but instead support the body's immune response when sick through faster recovery, decreased symptoms, and lower inflammation. Immune supporting meals contain five key components: produce, probiotics, fiber, healthy fats, and protein.
Produce: Micronutrients like vitamin C, carotenoids, and polyphenols help support immune response through modulating inflammation responses. Food sources include citrus, berries, leafy greens, and bell peppers. Aim to fill half of your plate with colorful produce at most meals.
Probiotic-Rich Foods: Probiotics are live, beneficial bacteria that support a healthy gut microbiota. 70-80% of the immune system resides in the gut, highlighting the vital role microbiota play in proper immune functioning. Eating probiotic rich foods can increase the diversity and quantity of the beneficial bacteria, support the gut barrier function, and reduce inflammation triggered by pathogens. Larger quantities of diverse microbiota in the gut take up space, and push out harmful bacteria, offering protection from harmful bacteria entering circulation of the body and causing harm. These microbiota use fiber as food, which helps them thrive. Probiotic rich foods include greek yogurt, kefir, kimchi, sauerkraut and fermented pickles.
Fiber: Research supports that high fiber diets directly promote “beneficial host immune responses against viral infection,” particularly against the flu. Fiber supports immunity because it creates fermentation byproducts called short chain fatty acids (SCFA), that elicit anti-inflammatory properties, overall supporting immune health. There are two categories of fiber- soluble and insoluble. Soluble fibers dissolve in water, and are also known as fermentable, meaning they are fermented by the microbiota located in the gut microbiome. Soluble fibers include oats, apples, beans, and flaxseeds. The second category of fibers are insoluble fibers. Insoluble fibers do not dissolve, which aids in creating bulk and regular bowel movements. Insoluble fibers include: whole wheat, most vegetables, and nuts. It is recommended for adult women to consume at least 25g of fiber/day and adult men to consume at least 38g/day.
Healthy Fats: Healthy fats like monounsaturated and polyunsaturated fatty acids help reduce inflammation and improve the absorption of fat-soluble vitamins (A,D,E,K). Improved absorption of vitamins helps them work better in our body. Health fats include avocados, olive oil, chia seeds and nuts.
Protein: Protein plays numerous roles in the body, but one of its most significant roles is to provide the building blocks to create new immune cells and antibodies. This is an essential component of fighting infection and repairing tissues. When choosing a protein source, look for lean, high-quality protein sources. Protein options include: lean beef, pork and poultry, fish, greek or icelandic yogurt, eggs, and plant proteins like soy, lentils, and legumes.
Nutrition alone can’t prevent the flu, but it can support recovery and decrease the severity of symptoms. A diet rich in produce, probiotics, fiber, healthy fats, and quality protein provides nutrients that will support the functioning of your immune system. In addition to eating well, adequate rest and sleep, hydration, and reduced stress are also important components to flu recovery.
Sources:
https://www.cdc.gov/fluview/surveillance/2025-week-53.html
Samuel Philip Nobs, Niv Zmora, Eran Elinav. 2020. Nutrition Regulates Innate Immunity in Health and Disease. Annual Review Nutrition. 40:189-219. https://doi.org/10.1146/annurev-nutr-120919-094440
Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ. The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients. 2021;13(3):886. Published 2021 Mar 9. doi:10.3390/nu13030886
Sidhu SRK, Kok CW, Kunasegaran T, Ramadas A. Effect of Plant-Based Diets on Gut Microbiota: A Systematic Review of Interventional Studies. Nutrients. 2023 Mar 21;15(6):1510. doi: 10.3390/nu15061510. PMID: 36986240; PMCID: PMC10057430.
Spragge, Frances, Erik Bakkeren, Martin T. Jahn, Elizete B. N. Araujo, Claire F. Pearson, Xuedan Wang, Louise Pankhurst, Olivier Cunrath, and Kevin R. Foster. “Microbiome Diversity Protects against Pathogens by Nutrient Blocking.” Science 382, no. 6676 (December 15, 2023): eadj3502.
