Winter is historically cold and flu season. Are you and your family prepared? Making simple changes in your dinner menus could make a difference in whether or not you get sick.

How Does Your Diet Affect Your Immunity? 

Diet affects immunity in many ways. For example, vitamin C may shorten a cold’s severity or duration. Beyond nutrition, the foods you eat impact your immunity by affecting your overall inflammation levels.

Certain substances promote widespread systemic inflammation, especially if consumed in large quantities. Sugar is a common example. When you regularly consume foods that lead to blood sugar spikes, you can develop insulin resistance from your body’s attempt to store the excess energy.

Systemic inflammation means your body is already under stress. Stress from any source makes you more prone to infection by lowering your immune response. You simply have fewer reserves to devote to the invading germs. However, eating more of the right foods and less of those that trigger inflammation can help you avoid getting sick this winter and improve year-round health.

What to Eat More of During Winter for Maximum Immunity

Adding more of the following foods to your diet during the winter months helps you maximize your body’s immune response.

1. Red Peppers

Both the spicy and mild varieties boost your immunity. Hot red peppers contain capsaicin — a substance that activates special receptors in your spleen, which is your largest immune system organ. It stimulates the release of specialized immune cells that bolster your body’s defenses.

Red bell peppers have more vitamin C than an orange and may be a better bet than citrus fruits for getting your recommended dose because they’re also less acidic. While the occasional orange is healthy, citrus fruits also contain acids that can damage tooth enamel, which can lead to discoloration and cavities. Highly acidic foods can also cause gastric upset. Bell pepper strips are more versatile — add them to sandwiches, salads and wraps while using them as an ingredient in other dishes.

2. Dark, Leafy Greens 

Broccoli and kale both come into season as cold weather approaches. Perhaps Mother Nature intended that purpose, as dark, leafy greens are nutritional powerhouses that can boost your immunity over the winter months.

Leafy greens are rich in vitamins A, C, E, K, and folate and the minerals magnesium, iron, calcium, and potassium. Additionally, they’re rich in fiber that nurtures your gut microbiota and can reduce systemic inflammation. They’re abundant in various antioxidants that fight disease by whisking free radicals out of your body before they can cause harm.

3. Honey 

Swapping sugar for honey may be the best move you make for your health in 2025 — and it’s a nearly effortless switch. Although honey is mostly sugar, it doesn’t affect your blood glucose and may help prevent diabetes thanks to its antioxidant and probiotic properties.

Additionally, honey has impressive antimicrobial properties. You can use medical-grade honey topically to treat burns and wounds, but taking it internally may bolster your body’s defenses sweetly.

4. Fatty Fish 

Fatty fish is rich in omega-3 fatty acids, which most Americans don’t get enough of. You need both omega-3 and omega-6 fatty acids for good health and a strong immune system, but many U.S. diets are much higher in omega-6.

Not having balance between the two can lead to inflammation that puts you at a higher risk of getting sick. Salmon is a great source of omega-3, but you can find it in plant-based foods such as chia, flax and hemp seed if you follow a vegan lifestyle.

5. Fermented and Probiotic-Rich Food 

Fermented and probiotic-rich foods contain strains of beneficial bacteria that nurture your intestinal microbiome. According to David Heber, MD, PhD, and professor emeritus at UCLA Health, 70% of your immune system exists in your intestines.

Fermented foods include popular treats like sauerkraut and kimchi, but you can ferment nearly any vegetable. Probiotic-rich foods such as yogurt often have the live bacteria added in after pasteurization. Kefir and kombucha are alternative good sources. 

What to Avoid Over the Winter 

Eating more of the above foods boosts your immunity even more when you also avoid these inflammation-causing eats.

1. Sugar 

Sugar causes blood sugar spikes and crashes, which increase inflammation in your body over time. Your body tries to store the excess energy in fat cells, which can also lead to unwanted weight gain.

2. Bleached Flour 

This substance may be your main reason for avoiding living on processed convenience meals. Manufacturers remove the fiber and nutrient-rich outer layers before giving such flour a bleach bath, and too much can increase your diabetes risk and spur inflammation.

3. Alcohol 

Alcohol is highly inflammatory, so if you don’t drink, don’t start. If you do, stick to the recommended one or two glasses per day. 

4. Trans Fats 

Although the FDA banned partially hydrogenated oils — a source of artificial trans fat — you’ll still find trans fats in many baked and fried foods. Look for meals that are roasted, grilled, steamed or stir-fried to steer clear. 

Boosting Your Winter Immunity Through Diet

The foods you choose can impact your immunity. Improve your chances of staying healthier through the winter months by adding more of the right foods to your diet.

Author: Mia Barnes