A super food contains a variety of disease-fighting nutrients, is readily available, economical and delicious without the need for salty seasoning or added fat, says Pittsburgh sports dietitian and Academy of Nutrition and Dietetics spokesperson Heather Mangieri. Immunity-boosting super foods provide the nutrients your body needs to not only fend off viruses and infection, but also help your body fight against immune-related illnesses such as arthritis. They can even help prevent certain types of cancer, according to the Academy of Nutrition and Dietetics. We all want to do everything we can to protect ourselves from getting sick, especially when cold and flu season rolls around. Here are eight super foods you can incorporate into your diet that will give your immune system a boost.

Sweet Potato

Sweet potatoes make the perfect super food. As one of the best food sources of vitamin A – meeting 561 percent of the daily value in one potato – the sweet potato has some serious immune-boosting powers. Vitamin A supports immune health by keeping your natural barrier to germs healthy and strong – your skin and mucous membranes in your digestive tract and lungs. Get the nutritional benefits for good health in one whole sweet potato and enjoy it baked, mashed or cubed and sautéed with onions for a tasty hash.

Greek Yogurt

Greek yogurt is a thick and creamy fermented snack food loaded with friendly bacteria known as probiotics. These microorganisms improve your body's ability to fight off infection, reduce inflammation and decrease the growth of harmful bacteria in your gut. The benefits aren't limited to just Greek yogurt, but are found in any yogurt with "live and active cultures" written on the label. Including one 4-ounce to 6-ounce serving of Greek yogurt a day not only fills your gut with bacteria that enhances immunity, but also helps you meet your daily calcium, vitamin D, potassium and protein needs.

Green Tea

Rich in the potent antioxidants polyphenols, green tea may lower your risk for a number of different types of cancer, including lung, colon, stomach and pancreatic. According to a review article published in "Chinese Medicine," the polyphenols in green tea may also help fight off Helicobacter pylori – the bacteria that causes stomach ulcers. While green tea offers a number of immune-promoting benefits, it is a source of caffeine and drinking too much may affect iron bioavailability. One to two cups of green tea a day gets you the benefits without the ill effects.

Garlic

As a super food, garlic not only adds flavor to your favorite dishes without the need for fat or salt, but also the bioactive chemical called allicin. This chemical is believed to have antibacterial activity that may help you fight off infections caused by Salmonella, Escherichia coli and Staphylococcus aureus. Getting more garlic in your diet may also help you fight off the common cold, although the National Institute of Health says more research is necessary before recommendations can be made. For immune health, one clove of raw, crushed garlic a day should do it.

Mushrooms

Mushrooms are low in calories and rich in a number of health-promoting nutrients including B vitamins, selenium, potassium and vitamin D. But it's a component called beta-glucan in mushrooms that helps bolster your immune system and may also protect against cancer, as well as slow tumor growth. Shiitake, oyster and split gill mushrooms are the best sources of beta-glucan. Consume 1 ounce, cooked or raw, a day to improve your nutrient intake.

Oysters

Your body needs zinc to make infection-fighting blood cells called T-lymphocytes. Not getting enough zinc in your diet may impact your body's ability to fight off infection, including respiratory illnesses such as pneumonia. Three ounces of cooked oysters contains 74 milligrams of zinc, meeting 493 percent of the daily value. If you're not a fan of oysters, Alaskan king crab, lean hamburger or fortified whole-grain breakfast cereal may also help you get more zinc.

Honey

Honey has been used for medicinal purposes since ancient times. Honey's high sugar content, acidity and array of phytochemicals are believed to be the components that help fight off bacteria such as E. coli and Staph aureus. It is also used topically to repair wounds, and when ingested, may help repair gastric ulcers and reduce inflammation. You need 1 to 5 tablespoons of raw (unpasteurized) honey a day to get the medicinal benefits. Use it in place of other sweeteners in baked goods, hot cereal and tea to get your daily fix for health. (Children under one year old and those with weak immune systems should not consume raw honey.)

Blueberries

Blueberries pack powerful immune-boosting punch. Blueberries are low in calories, high in fiber and a good source of vitamin C and manganese. They are also rich in polyphenols, which in addition to being powerful antioxidants, also have anti-inflammatory properties. Additionally, researchers have isolated a compound in blueberries called pterostilbene, which in combination with vitamin D increases the expression of the cathelicidin antimicrobial peptide, or CAMP gene, that is involved in immune function. One cup of blueberries can help up your nutrient intake for immune health.