What to Eat for Immune Health: 5 Foods to Avoid and 5 to Add to Your Plate

A strong immune system is your best defense against seasonal colds, flu, and even chronic illness. The foods you eat every day can either support your immune system or weaken it. If you feel like you’re getting sick often or just can’t shake that run-down feeling, what’s on your plate may be part of the problem.

Today, we’ll explore five foods that weaken the immune system—and their healthier swaps—plus five powerful foods that strengthen immunity naturally.

🚫 5 Foods That Weaken the Immune System

These foods contribute to inflammation, blood sugar spikes, and nutrient depletion –three of the biggest immune system stressors.

1. Ultra-Processed Sugary Foods

Cookies, candy, soda, and sweetened coffee drinks can temporarily lower your immune defenses by reducing the activity of white blood cells for several hours after eating. Sugar also feeds “bad” gut bacteria, which can throw off the balance of your gut microbiome—where about 70% of your immune system lives. Swap: Choose naturally sweet foods like berries or an apple with almond butter to satisfy cravings.

2. Refined Grains

White bread, pastries, and many boxed cereals have been stripped of fiber and vitamins, causing quick blood sugar spikes. These spikes can lead to higher levels of insulin and inflammation, making it harder for immune cells to work effectively. Swap: Reach for whole grains like quinoa, oats, and brown rice to keep blood sugar steady and support healthy gut bacteria.

3. Fried and Fast Foods

Deep-fried foods and fast-food meals are high in oils that promote inflammation. These oils can increase compounds in the body called cytokines, which are like “fire alarms” for inflammation—good in small amounts, but harmful when constantly triggered. Swap: Oven-bake or air-fry at home with avocado oil or olive oil for a healthier crisp.

4. Alcohol

There is likely no amount of alcohol that is 'good' for us... Excessive drinking suppresses the production of infection-fighting white blood cells and makes it harder for your body to absorb nutrients like zinc and B vitamins. This can leave you more vulnerable to colds and infections. Swap: Try mocktails made with sparkling water, fresh citrus, and herbs like mint or basil.

5. Highly Processed Meats

Hot dogs, bacon, and deli meats often contain preservatives called nitrates, which can stress your cells and increase inflammation. These meats are also high in sodium, which can strain the immune system by putting extra stress on the kidneys and circulation. Swap: Opt for organic roasted chicken, wild-caught salmon, or plant-based proteins like lentils.

Seasonal fruits like citrus and pomegranates are packed with immune supporting vitamin C.

🥦 5 Foods That Strengthen the Immune System

These whole foods are rich in vitamins, minerals, and phytonutrients that help your body defend against illness.

1. Fruit

Oranges, lemons, grapefruits, kiwis, pomegranates, and strawberries are packed with vitamin C. This powerful antioxidant helps white blood cells find and destroy germs faster, and it supports the production of collagen, which keeps your skin (your first line of defense) healthy and strong.

2. Garlic

Garlic contains allicin, a natural compound that helps the body fight infections. Studies show that garlic can stimulate certain immune cells, like macrophages, which “eat up” viruses and bacteria.Tip: Chop or crush garlic and let it sit for 10 minutes before cooking to boost the amount of allicin it produces.

3. Leafy Greens

Spinach, kale, and Swiss chard deliver folate, vitamin C, and antioxidants that help immune cells multiply and fight off invaders. They also contain vitamin A, which helps keep mucous membranes in your nose and throat healthy—another important defense barrier.

4. Mushrooms

Shiitake, maitake, and reishi mushrooms are rich in beta-glucans, special fibers that “train” the immune system to respond more effectively to threats. Research shows mushrooms can increase natural killer cell activity, which helps your body fight viruses. Pro tip: avoid eating raw mushrooms, the more you cook mushrooms the better they are for your immune health.

5. Fermented Foods

Yogurt, kefir, sauerkraut, and kimchi supply probiotics—beneficial bacteria that strengthen the gut lining and prevent harmful microbes from getting into the bloodstream. A healthy gut microbiome is closely tied to a strong immune response.

Food as Medicine for a HEALTHY & STRONG Immune System.

🧾 Key Takeaways

• Avoid: Sugary snacks, refined grains, fried/fast foods, excess alcohol, processed meats—these promote inflammation and slow down immune response.

• Add: Fruit (especially citrus, kiwi, and strawberries), garlic, leafy greens, mushrooms, fermented foods—these provide vitamins, antioxidants, and healthy bacteria that keep your immune system in top shape.

• Even small daily swaps—like trading soda for sparkling water or adding a handful of spinach to your smoothie—can create a big shift in your immune strength.

  
  

👩‍⚕️ Your Next Step

Ready to strengthen your immune system naturally and prevent frequent colds and fatigue? Schedule a visit with Dr. Rachel Winstedt, ND to create a personalized immune-support plan.

📥 Free Resource: Download our Stress Survivor to Thriver Guide for even more lifestyle tips to keep your immune system strong.