8 Foods That Boost Your Immune System

Besides saying goodbye to the summer sun and sweltering heat, the switch into the fall season also welcomes a total change of routine. Summer vacays are over and we’re trading in iced coffees and lattes for their warmer, pumpkin-flavored counterparts. And for whatever reason, it feels like there’s less time to eat healthy, sleep and exercise.

But staying on track with our bodily cycles is essential to staying healthy during the colder months.“To ward off sickness, we have to eat a wide variety of fruits and vegetables, as each have unique vitamins and minerals that complement one another and offer different health benefits,” says Millie Wilson, R.D., registered dietitian at My Fit Food. Your best bet is to eat foods from every color of the rainbow for maximum exposure to illness-fighting nutrients. Here are eight R.D.-approved foods that help boost your immune system and keep you healthy year-round.

Spinach

Jam-packed with a slew of nutrients, this desirable, leafy green is a certified winter superfood. “Spinach is rich in zinc, which helps maintain our immune system levels, as well as health-promoting phytonutrients like carotenoids and flavonoids, which pack powerful antioxidant protection,” Wilson says. Since the amount of nutrients in a food can be reduced after it has been boiled or stewed, it’s best to enjoy your primary source of spinach raw or lightly sautéed. Try using it as the main greens in your hearty salad or pile some over an open-faced sandwich.

Nuts and seeds

Both of these crunchy counterparts are essential to a healthy diet. They’re an excellent, all-natural source of vitamins, minerals, protein, fat, fiber and some even contain cancer-fighting antioxidants. “Almonds, walnuts, pumpkin seeds and sunflower seeds are all rich in vitamin E, which is important for the normal functions of the immune cells,” says Karen Lau, M.S., R.D., registered dietitian at Joslin Diabetes Center in Boston. Vitamin E can be found in almost all nuts and seeds; can be eaten raw, blanched or ground into a flour; and works with vitamin C to ward off certain chronic diseases. Because both nuts and seeds are incredibly versatile, you can toss them into both sweet and savory dishes from oatmeal and cereal to salads and dinner entrees.

Green tea

This herbal treat has been cherished since ancient times for its soothing and healing benefits for the body and mind. And we still consider green tea to be one of the healthiest herbs around. “Rich in antioxidants, green tea may help protect your body from oxidative damage, and some studies have also shown green tea may help fight against influenza viruses, especially at its early stage,” says Lau. A new type of green tea on the market is called matcha, essentially green tea leaves ground up into a fine powder. “Because matcha is the only tea where the leaves are consumed instead of steeped, you can simply mix the powder with milk or water for an extra punch of antioxidants,” says Wilson. So hydrate and stay warm and healthy in the chilly fall months with a cup of hot green tea.

Lean cuts of meat

While not commonly considered a food that’s essential for maintaining a healthy immune system, lean cuts of meat do help keepa you healthy. “The immune system is made up of various proteins, therefore a diet lacking in protein can lead to a compromised immune system and increased susceptibility to infection,” says Wilson. “Supplying your body with an adequate amount of protein equips your immune system with the tools it needs to fight off illness.” If you’re vegan or vegetarian, be sure to get your protein fill from meat substitutes like tofu, tempeh and seitan, as well as legumes like lentil and black beans.

Quinoa

Recent research has focused on the importance of gut health and its relationship to immunity. And quinoa, an ancient grain and complex carbohydrate, has been found to be instrumental in promoting gut health. “By eating high-fiber complex carbohydrates like whole grains, fruits and vegetables, our bodies increase the amount of good gut bacteria, called probiotics,” says Wilson. “And probiotics help to defend against harmful bacteria that enter the gut and can make us sick.” In addition to its tastiness and ability to keep us full for longer, quinoa is an incredibly versatile grain that can be eaten for breakfast, lunch or dinner. Try adding it to a soup or chili for a boost of protein and fiber.

Bulb vegetables

Aromatic and loaded with flavor, bulb vegetables like garlic, onion, chives, shallots and leeks have countless antibacterial and antiviral effects. They contain what is known as “organosulfur compounds,” which have been shown to protect against chronic conditions and diseases like heart disease and cancer. Research has looked at how these vegetables, all from the allium family, help flush the body of harmful toxins, stimulating immune responses and reducing bodily inflammation. One study from the National Cancer Institute found that eating two teaspoons or more of garlic, onions or scallions a day can significantly lower an individual’s risk of prostate cancer. Power to the bulb!

Citrus fruits

You’ve probably heard that drinking orange juice can help fight off a cold. While that hasn’t necessarily been proven, sipping OJ has been shown to decrease the length of cold symptoms. “Oranges are rich in vitamin C, which is known to boost your immune system, as well as free radical-fighting antioxidants that may help in preventing or delaying certain types of cancer,” says Wilson. “But it’s important to know that vitamin C is lost fairly easy in cooking, so it’s best to eat these foods raw or cooked for a short amount of time to get the most vitamin C out of them.”

Colorful vegetables

We’re talking red, orange, purple, green, etc. Enjoying a plate full of rainbow-inspired veggies, like red, orange and green peppers, broccoli, red cabbage, carrots, mushrooms and more, can help keep your health in check. “Each color provides different nutrients—like vitamins A , C and E—and antioxidation function, which are important in protecting and boosting your immune system,” says Lau. Try to include a couple colors of vegetables at each dinner and an even wider variety throughout the week.

Jenn Sinrich is an editor in New York City, a self-proclaimed foodie always looking for the healthier version of all recipes, a passionate lover of all things cheese, a friendly New Yorker, Bostonian at heart and proud Red Sox fan. Love cats? Cheese? Mac n' Cheese? Follow her on Twitter and Instagram.