Eating for Immunity: How to Support Your Immune Health
Picture this: it’s the middle of flu season.
Your coworker is sneezing nonstop, your family is fighting off colds, and the person behind you in the grocery line sounds like they’ve swallowed a foghorn. Yet, somehow, a handful of people seem completely unfazed—healthy, energetic, and breezing through flu season while others catch every bug going around. What’s their secret?
It all comes down to your immune system: a complex, defense network – featuring white blood cells, antibodies, and the lymphatic system – working 24/7 to identify and neutralize threats like bacteria and viruses.
But what happens when this intricate system gets overwhelmed, and you wind up sick with a head cold or the flu? Is there anything you can do to bolster your defenses and stay well this winter?
The truth is, while it’s common to get sick, especially during winter, you’re not powerless against seasonal illnesses. You have more control than you think. The food you eat can be a game-changer for your immune health. By prioritizing the right nutrients, you can support your body’s natural defenses, stay healthy, and ward off illness.
How does the food you eat impact your immune system?
Your immune health is closely tied to the nutrients that you eat, largely because of their impact on inflammation and something called oxidative stress. Oxidative stress happens when there’s an imbalance between free radicals—unstable molecules that can damage your cells—and the antioxidants that help keep them in check (Iddir et al., 2020). Think of antioxidants as the “good guys” protecting your body’s cells from harm. Chronically elevated oxidative stress and inflammation not only contribute to long-lasting viral infections, such as Epstein-Barr virus (EBV), but are also implicated in many chronic inflammatory conditions, such as metabolic syndrome and cardiovascular diseases (Iddir et al., 2020).
Micronutrients support your immune health in three primary ways:
1) Your Body’s Innate Barriers
Micronutrients maintain the structural and functional integrity of mucosal cells in your body’s physical and biochemical barriers, such as the skin (Gombart et al., 2020). For example, vitamin A is essential in the process of organizing white blood cells to protect against harmful microbes in the gastrointestinal system, helping to support gut health (Gombart et al., 2020).
2) Immune Cells
Micronutrients support innate immune cells, your body’s first line of defense against infections. They have antimicrobial effects and help regulate inflammation. Vitamin C, for example, is an antioxidant that protects cells from damage that can occur when immune cells attack invaders — a process called oxidative burst (Gombart et al., 2020). What this means is more antioxidants in your diet can help protect your body’s cells as your immune system works to fight off infection.
3) Antibodies
Lastly, micronutrients are vital for antibody production, as well as responses to antigens. Antibodies are essential for immune health as they are proteins that your immune system uses to recognize and neutralize threats like viruses and bacteria.
The relationship between immune health and micronutrients in the foods you eat is highly complex. One of the best things you can do for your health this winter is to add more diversity to your diet to ensure you’re eating adequate amounts of all micronutrients.
When you’re at the grocery store, make it a goal to pick up at least one fruit or vegetable that you’ve never tried or don’t typically cook with. Foods like kiwi, purple sweet potato, or bok choy might excite your taste buds and supply your body with the nutrients it needs to stay healthy.
Nutrients to Prioritize this Winter to Support Immune Function
Vitamin A
Helps support the gut lining and sends antibodies to fight infections in the gut, helps with the clean up of harmful invaders, aids in a balance of healthy immune signals, and supports antibody production, especially in protecting the gut (Calder, 2022).
Eat more: beef liver, sweet potatoes, spinach, carrots, cantaloupe, eggs, peppers.
Quick tip: Vitamin A is most bioavailable and best absorbed from animal products like meat and fish. Be sure to eat vitamin A-rich foods with fat to enhance absorption.
Try this:
Vitamin C
Promotes antibody production, collagen synthesis, wound healing, and encourages healthy skin cell growth—essential for maintaining a strong skin barrier. Vitamin C also helps protect your cells from oxidative damage and is involved in the body’s defense against pathogens (Calder, 2022).
Eat more: red bell peppers, broccoli, Brussels sprouts, lemon, cauliflower, oranges, strawberries, kiwifruit
Quick Tip:
Vitamin C is sensitive to heat exposure, so limit the use of heat when preparing vitamin C-rich foods. Steaming is the best technique to cook broccoli while retaining vitamin C content.
Eat seasonally: vitamin C is highest in produce that’s in season, so choose fresh in-season items or frozen fruits and veggies, as they’re usually frozen at peak freshness.
Try This: Struggling to add more vitamin C to your diet? Try drinking more water infused with vitamin C-rich fruits.
Vitamin D
Promotes production of antimicrobial proteins and strengthens the gut barrier, helping to maintain the integrity of the gut lining. Vitamin D also supports the skin barrier and helps generate specialized immune cells to reach infection sites and initiate the appropriate immune response (Calder, 2022).
Eat more: cod liver oil, salmon, trout and other fatty fish, mushrooms, eggs, beef liver
Quick tip: Increase sun exposure (our primary source of vitamin D). Try to get direct sunlight exposure first thing in the morning shortly after waking to help regulate sleep-wake cycles.
Try this:
Vitamin E
Protects against oxidative damage (vitamin E is a powerful antioxidant!), supports key immune cells (like Th-1 cells) that help fight off pathogens, and contributes to immune balance—making sure your body doesn’t mistakenly attack its own tissues (also known as autoimmunity) (Calder, 2022).
Eat more: sunflower seeds, almonds, kiwi, broccoli, hazelnuts, peanuts, spinach
Quick tip: Make sure to pair vitamin E-rich foods with fat for better absorption.
Try this: Add almond butter to your smoothie or top a spinach salad with sunflower seeds and sliced avocado.
B-Vitamins
Vitamin B12 is necessary for antibody production and for gut bacteria to perform important metabolic functions (Calder, 2022). Other B vitamins like folate and B6 also support antibody production and promote intestinal homeostasis in the gut (Calder, 2022).
Eat more: meat (especially beef liver) and fish for vitamin B12. Leafy greens are a good source of folate, while chickpeas, tuna, salmon, and chicken are good sources of vitamin B6.
Quick tip: Focus on eating more animal products to increase vitamin B12 intake and add dark leafy greens to every meal to boost your folate levels.
Try this:
Zinc
Helps to maintain the integrity of the skin and mucosal linings (like those in your mouth and gut), supports the complement system—your body’s built-in pathogen detection squad—and aids in producing immunoglobulin G (a key antibody) to help prevent infections (Calder, 2022).
Eat more: pumpkin seeds, oysters, beef, turkey, pork, cheese, shrimp, lentils, Greek yogurt, peanuts
Quick tip: Zinc is best absorbed with a protein-rich meal.
Try this:
Cook a warming lentil vegetable curry to up your zinc intake.
Bonus Tips to Support Immunity
SLEEP
Sleep is crucial for your immune health, and there are many immune functions which occur in sync with the sleep-wake cycle (aka circadian rhythm) (Besedovsky et al., 2012). Your body’s immune cells prioritize a quick response to invading antigens and work to repair tissue damage during the wake period, while memory T cells peak during sleep to promote immunological memory, allowing your body to respond more rapidly and effectively to pathogens it encountered previously (Besedovsky et al., 2012). Without adequate sleep, your body is in a state of chronic low-grade inflammation, which not only increases your need for antioxidants, but can also lead to much more serious health conditions.
Check out some of our favorite products to promote better sleep:
Magnesium glycinate before bed
Lavender essential oil
White noise machine
Valerian root tea
PROTEIN INTAKE
Low protein status can increase the risk of infection (Gombart et al., 2020) and protein is also crucial for gut health. Proteins are essential building blocks for many immune components, including immunoglobulins (antibodies) and the gut-associated lymphoid tissue (GALT).
GALT is a part of the immune system located in the gut that helps defend against pathogens entering through the digestive tract. A lack of proteins can impair its development and function, weakening gut-mucosal immunity, and low protein levels could also lead to lessened antibody production (Iddir et al., 2020). Additionally, high-quality protein can reduce the post-meal blood sugar response and increase satiety. Ensure you’re getting healthy protein with every meal/snack, including eggs, wild-caught fish, grass-fed meat, legumes (e.g. lentils, chickpeas), and Greek yogurt.
By making small, intentional changes to your diet and lifestyle, you can take powerful steps toward supporting your immune health this winter.
Fuel your body with nutrient-rich foods, prioritize quality rest, and trust in your ability to build resilience. Your health is in your hands— consistent choices to prioritize your wellbeing have the power to keep you strong all season long.
Sources:
Besedovsky, L., Lange, T., & Born, J. (2012). Sleep and immune function. Pflugers Archiv: European Journal of Physiology, 463(1), 121–137. https://doi.org/10.1007/s00424-011-1044-0
Calder P. C. (2022). Foods to deliver immune-supporting nutrients. Current Opinion in Food Science, 43, 136–145. https://doi.org/10.1016/j.cofs.2021.12.006
Gombart, A. F., Pierre, A., & Maggini, S. (2020). A review of micronutrients and the immune system-working in harmony to reduce the risk of infection. Nutrients, 12(1), 236. https://doi.org/10.3390/nu12010236
Iddir, M., Brito, A., Dingeo, G., Fernandez Del Campo, S. S., Samouda, H., La Frano, M. R., & Bohn, T. (2020). Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis. Nutrients, 12(6), 1562. https://doi.org/10.3390/nu12061562