Winter is right around the corner, and the days are getting colder and darker. As temperatures drop, the air becomes drier, which allows viral particles to stay airborne longer. We also spend more time indoors, making it easier for infections to spread. In other words: your immune system has to work harder this time of year, and it can use a little extra support.
Fortunately, there’s a lot you can do to keep your immune system strong. Simple habits like washing your hands more often, using a humidifier and making a few smart food choices can make a difference. In this article, we’ll walk through 10 foods that have been researched for their immune-supporting benefits, and explain exactly how they help your body defend itself.
How Your Immune System Works
Your immune system protects you from viruses, bacteria, and anything else that doesn’t belong in your body. It removes damaged, harmful or abnormal cells and helps repair tissue after injury. It has two main parts:
Your innate immunity
This is your body’s built-in first line of defense and includes roughly four types of barriers:
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Physical barriers, like your skin and mucous membranes
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Body fluids, such as stomach acid, saliva, and tears
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White blood cells, that attack invaders
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Proteins in your blood, that help destroy bacteria
Your adaptive immunity
This immunity develops throughout your life, as you get sick or get vaccinated. It helps your body recognize and respond faster the next time you encounter the same pathogen.
Two types of immune cells play a major role:
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B cells: produce antibodies that recognize and neutralize germs
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T cells: coordinate immune responses, kill infected cells, and help stop the response once an infection has been cleared
These cells are found in your bone marrow, thymus, lymph nodes and spleen.
Food and Their Role in Your Immune System
Healthy lifestyle habits like adequate sleep, regular physical activity, proper stress management, not smoking and balanced nutrition, are always your strongest foundation and defense against germs.
Nutrition is a big part of that foundation. Here are 10 foods that can help support your immune system:
1. Citrus fruits (oranges, clementines, grapefruits, lemons, limes)
These are packed with vitamin C, which helps your body produce more white blood cells, supports your skin and mucus barriers, and works as an antioxidant that protects your cells from damage.
Vitamin C also helps your immune cells communicate more effectively and shortens the lifespan of harmful free radicals, which reduces stress on the immune system.
Because your body cannot store or make vitamin C, eating citrus regularly is an easy way to support your immune system, especially when you’re feeling a bit under the weather.
2. Papaya
Besides vitamin C, papaya contains β-carotene. This can be converted into vitamin A, which has been shown to improve the body’s immune response and support growth, reproduction, and the production of blood cells.
Vitamin A also keeps your respiratory and gut lining strong, which is part of your body’s first barrier against germs, making it harder for pathogens to enter.
3. Pomegranate
Pomegranate juice can suppress harmful bacteria like E. coli and Salmonella, and has antiviral properties against viruses like flu. It also supports healthy gut bacteria.
Its immune benefits mainly come from polyphenols, which are powerful antioxidants that can reduce inflammation by lowering oxidative stress (oxidative stress is an imbalance between harmful free radicals in your body and the antioxidants that normally keep them under control).
Go for pomegranate seeds if you want to maximize your fiber intake:
3.5 oz (100 grams) of pomegranate seeds contain 4 grams of fiber
3.5 oz (100 grams) of pomegranate juice contains 0 grams of fiber
4. Almonds
Almonds are a great source of vitamin E, which is along with vitamin C essential for maintaining a strong immune system. They also contain healthy fats and have anti-inflammatory effects on cardiovascular diseases. Vitamin E protects the fatty membranes of your cells from damage, which keeps immune cells stable and effective. Vitamin E also supports T-cell development.
5. Broccoli
The AmiVital’s team favorite green veggie! We like to eat it fresh out of the oven (not too long, then it loses most of its nutrients), with a drizzle of olive oil, a bit of garlic powder and freshly cracked black pepper. Broccoli contains vitamin A, C and E, fiber and antioxidants. It has anti-inflammatory properties and promotes eye and bone health.
Its key compound, sulforaphane, activates your body’s natural detoxification pathways and reduces internal inflammation, allowing immune cells to work without interruption.
Steaming is the best way to prepare broccoli, as it keeps the nutritional qualities intact: sulforaphane is sensitive to heat.
6. Cow’s milk
Cow’s milk contains vitamins (particularly B-vitamins), minerals and bioactive peptides that can support immunity. B-vitamins help your body produce blood cells, and the mineral zinc supports the function of natural killer cells.
Milk proteins like whey and casein break down into smaller peptides that directly stimulate immune cell activity and help regulate inflammation.
7. Yogurt and curd
Yogurt, made by fermenting milk with lactic acid and bacteria, offers enhanced health benefits compared to milk. That’s because certain minerals, like calcium, are more easily absorbed by the body compared to milk.
Yogurt supports gut health by increasing beneficial bacteria, which suppress harmful microbes and can reduce infections. Since nearly 70% of your immune system lives in your gut, this increase in healthy gut bacteria directly strengthens immune responses and reduces inflammation.
Regular yogurt consumption may lower the risk of cardiovascular disease, chronic kidney disease, and diabetes while strengthening overall immunity.
8. Turmeric
Curcumin is the active compound in turmeric, which has anti-inflammatory, antioxidant, antiviral, and immune-boosting properties. Curcumin can reduce exercise-induced muscle damage and regulate immune cell functions.
It works by blocking inflammatory pathways and decreasing the production of inflammatory molecules. Inflammatory pathways are a series of molecular signals that form the body’s protective response to pathogens, infection or tissue damage.
An important note on turmeric is that curcumin has a very low bioavailability. This means that the body only absorbs a small amount when eaten as regular turmeric powder. If you combine turmeric powder with black pepper, consume it in a fat-rich meal, and/or heat it, you increase the absorption.
9. Garlic
Garlic contains a lot of biologically active sulfur-containing compounds, which have been found to have antiviral properties. Garlic also has anti-inflammatory effects because some of its bioactive components can block inflammatory factors.
When garlic is crushed, the compound alliin turns into allicin, which helps your immune cells respond faster to invading pathogens and reduces oxidative stress.
10, Water!
Water is one of the most important immune boosters. It keeps your protective barriers strong: hydrated mucus membranes (in your nose, throat and lungs) trap viruses better. It also carries nutrients to your cell and helps flush out toxins and germs through your kidneys, urine and mucus when you’re sick.
Even mild dehydration slows down immune cell movement and makes it harder for your body to clear pathogens, which is why staying hydrated is key for daily immunity.
Conclusion
There you have it, 10 foods that will help you strengthen your immune system. Small, consistent choices in your diet can make a big difference in keeping your immunity strong year-round.
Remember though, that a healthy diet alone cannot prevent you from getting sick. It’s a combination of an overall healthy lifestyle, and a little bit of luck: sometimes we just can’t prevent getting the flu.