We all know when cold and flu season comes around, washing your hands is especially important. But so is what you put on your plate. What you eat can also boost your immunity to help you fight off bugs and stay healthy. "The immune system isn't a single entity," says Rachel Swanson, R.D., L.D.N., a registered dietitian nutritionist and the founder of the nutrition consulting firm Rachel's Rx in Los Angeles, California. "It's an exquisitely intricate, interconnected system. Our daily habits (including diet, exercise, sleep, and stress management) have a much greater impact than any one single intervention alone."

In other words, having healthy habits and stress management practices will be your best bet in boosting immunity.

"We can really boost our immunity through diet alone. Consistent intake of the micronutrients that help our bodies fight disease, is a natural solution to infection prevention," says Cassie Majestic, M.D., an emergency medicine physician at Hoag Hospital in Newport Beach, California. "Micronutrients, or vitamins and minerals, are vital to disease-prevention and health development."

Your body only needs small amounts of these nutrients (hence the "micro" in the name), but since the body does not make them on its own, we must include them in our diets. The best foods for the immune system are often full of:

• Vitamin C
• Vitamin E
• Vitamin B6
• Vitamin A
• Vitamin D3
• Zinc
• Magnesium
• Probiotics

10 of the Best Immune-Boosting Foods

"Without adequate nutrition, the immune system is deprived of essential components that generate an effective immune response and resistance to infection," Swanson says.

So fill your cart with these foods to strengthen immune systems (listed in no particular order). All come recommended by Swanson, Majestic, and Rachel Fine, R.D., a registered dietitian and owner of the nutrition counseling firm To The Pointe Nutrition in New York City.

1. Citrus Fruit

One of the strongest sources of vitamin C, lemons, limes, oranges, and grapefruit may support your body in its natural immunity process. For a bonus dose of the best foods for the immune system that are high in C, add strawberries and avocados to your shopping list, too.

2. Fermented Foods

Kimchi, tempeh, miso, and even kombucha are killer when it comes to combating germs.

"Fermented foods, and the probiotics they contain, are beneficial for the gut ecosystem," Swanson says. "The majority (about 80% ) of immune cells are housed within the gut, which reflects the importance of our diet in maintaining proper functioning."

3. Chicken Soup

It's good for the soul and strengthening your immune system.

"There's a reason why chicken soup makes its debut a lot during cold and flu season: Poultry, such as chicken, is high in B6, which helps with formation of new red blood cells," Swanson says.

And if you can stir in a handful of kale or chard, even better.

"Dark leafy greens are high in magnesium and vitamin E, a potent antioxidant," Swanson adds.

4. Yogurt

Probiotics are good for your gut and your immune defenses.

"Yogurt [with live active cultures] will boost your intake of probiotics to support a strong microbiome, and as a result, a strong immune system," Fine says. (What can your gut do for you? Turns out, a whole lot: here 5 gut health facts you need to know.)

5. Mushrooms

Among the most diverse and versatile veggies around (just look at all the types you can shop, chop, and savor!), mushrooms are one of the top 10 immune-boosting foods. The caps and stems offer beta-glucans, Swanson says, which are soluble fibers that research suggests may lower cholesterol, improve blood sugar control, and strengthen immunity. Reishi, shiitake, and maitake are especially rich in beta-glucans.

6. Matcha Tea

It's not just foods that help your immune system, drinks can too. The antioxidant EGCG, found in green teas (including matcha), inhibits the production of pro-inflammatory molecules, and is "shown to have multiple actions on immune cell function," Swanson says.

7. Sunflower Seeds

However you use this food that helps your immune system (whether tossed into trail mix or for topping your morning bowl of oats or yogurt) you'll be getting a potent dose of vitamin E.

If you're not in the mood to get seedy, "this powerful antioxidant can also be found in peanut butter and almonds," Fine says.

8. Sweet Potatoes

Roasted, toasted (yes, sweet potato toast is totally a thing!), or mashed, there are dozens of delicious ways to get your fix of this immune-boosting food. (Might we suggest starting with one of these 19 creative sweet potato recipes?) Sweet potatoes are a good source of vitamin B6, which has been shown to play a role in the development of healthy immune system function.

9. Microgreens

Go small for big immune-boosting food benefits of microgreens.

"The nutrient density of microgreens far outweighs that of their mature counterparts, providing higher concentrations of micronutrients like Vitamin C," Swanson says.

Among other important wellness tasks, vitamin C stimulates the production and function of white blood cells that protect the body from foreign invaders and infections.

10. Salmon

Add salmon to your diet for lots of polyunsaturated fatty acids (PUFAs). Two PUFAs in particular (DHA and EPA), are known to keep cells functioning properly and promote normal inflammatory responses. High amounts of DHA and EPA (two of the three main Omega 3s) make salmon one of the top immune-boosting foods.

Bonus Immunity Tips: Foods to Skip

It's also vital to steer clear of immune-weakening foods, too. The dietitians recommend limiting inflammatory foods, including:

• Added sugars
• Highly-processed items, including processed meats and refined carbohydrates
• Excessive alcohol

"These foods and drinks can cause the body to act as if it were fighting a bacterial infection, increasing the release of inflammatory cells and in turn causing chronic, unnecessary inflammation," Majestic says, which puts your entire system at risk for attack by bacteria and viruses.