Get a heads-up on cold and flu season.
You’ve got your hand washing routine on lock and are actively avoiding anyone with the sniffles. But unless you live in a literal bubble, you’re not going to be able to completely avoid germs. They’re everywhere. And with cold and flu season quickly approaching, it’s even more important to give our immune systems some help.
But it’s not just about warding off illness. While there’s still a lot to be understood on the matter, we do know that a healthy immune system benefits the health (and radiance) of your skin. So, we rounded up eight foods that can boost your immune system and help you keep the cold and flu at bay—or, if you’ve already got the sniffles, help you kick it faster.
Foods That Boost Your Immune System: Sweet Potatoes
Another reason to celebrate sweet potatoes: They’re full of beta-carotene, which helps increase T-cell activity. (Read: Your body is better able to fight against infection.)  Plus, beta-carotene is a powerful antioxidant.
Foods That Boost Your Immune System: Kefir
This fermented drink packs probiotics, including the bacteria bifodobacterium bifidum. Findings show that this particular strain can help boost your immune system and increase antibody levels.  (Bonus: It also helps with your digestion.) This bacterium can also be found in some yogurts, fermented vegetables, and our Gut Instinct probiotic supplement.
Foods That Boost Your Immune System: Blueberries
A study published in Molecular Nutrition and Food Research found that in conjunction with vitamin D, a compound in blueberries (called pterostilbene) seriously boosted the gene in our bodies that’s associated with immune function.  They’re also high in antioxidants, which help prevent damage to cells.
Foods That Boost Your Immune System: Mushrooms
Sorry, apples: Turns out that a mushroom a day is what actually could help keep the doctor away. A study done at the University of Florida’s Institute of Food and Agricultural Sciences found that eating a four-ounce serving of shiitake mushrooms for four weeks bolsters the immune system . It helps gamma delta T-cells (aka cell receptors that signal your immune system to fire up) function better, and also helps reduce inflammation.
Foods That Boost Your Immune System: Oats
Oats contain a special type of fiber called beta glucan. Studies show that it can help our infection-fighting blood cells. 
Foods That Boost Your Immune System: Egg Yolks
Egg yolks may have gotten a bad rap in the past for their cholesterol levels. But recent studies have found that the negative connotations are false.  Plus, the yolk contains high levels of zinc, an important mineral when it comes to controlling infections. A 2013 study found that it helps balance your immune response, preventing your immune system from going overboard when fighting infection, which can cause inflammation that makes you feel worse.  Plus, if you don’t get enough zinc in your diet, it can cause you to be more susceptible to germs and infections.
Other foods high in zinc are spinach, oysters, and chickpeas.
Foods That Boost Your Immune System: Citrus Fruits
File this under “obvi.” Citrus fruits like oranges and grapefruits are high in vitamin C.
#FBF to high school biology: Vitamin C is a nutrient that helps T-cells (the cells that fight infections and diseases) function optimally. If you don’t get enough vitamin C, your chances of getting sick increase.