Your immune system is your first defense against bacteria and microorganisms that cause disease. According to Harvard Health, nourishment is a key element in creating a healthy environment for your immune system. It makes sense when you consider that our gastrointestinal system represents 70 percent of our immune system (Journal of Clinical and Experimental Immunology). So, if you want to avoid the winter colds and flu viruses, try these immune boosting foods:

1. The “C” fruits and veggies. As you probably know, the science behind vitamin C shows that it promotes healthy immunity and can help decrease the severity and length of viruses like the common cold. That’s because vitamin C is a strong antioxidant (which protects against illness), and C helps your body absorb iron, which creates the pathogen-fighting cells and acids. While oranges (50 mg) probably come to mind, you might be surprised to know that foods that contain the most vitamin C per 100 grams include red and yellow bell peppers (185 mg); kale (120 mg), and if you really want your C to soar, try papaya and guava (228 mg). These foods contain double, triple and quadruple the DV (Daily Value) of vitamin C! Remember, this is a preventative measure - Airborne and similar products won't stop your cold.

2. White mushrooms. Mushrooms are a great source of vitamin B2, and they are also an antioxidant that helps your immune system fight free radicals. Further, mushrooms protect against inflammation, the source of many chronic diseases. Two cups of mushrooms provides half of the DV of vitamin B-2.

3. Chicken soup. You might have heard chicken soup referred to as “natural penicillin” because of its healing properties. Science backs that up, too. For those of you who are not vegetarians, chicken is a good source of vitamin B-6, which helps create new red blood cells in our body. The broth itself contains nutrients that keep our gastrointestinal system healthy, too, which in turn strengthens our immunity. Other studies show that chicken soup’s amino acids, as well as the hot water and steam, may help thin the mucous that drips down your throat when you have a cold or flu, shortening the length and severity of that annoying cough.

4. Sunflower seeds. If you’re looking for a quick snack, go for raw, unsalted sunflower seeds and boost your immunity with nutrients such as magnesium, phosphorus, vitamin B-6 and vitamin E. In fact, just a handful (1/4-cup) has almost the full DV of vitamin E, a disease-fighting antioxidant and a necessity to the healthy maintenance of our immune system.

5. Sesame seeds. Zinc increases the production of white blood cells that fight infection and helps the cells fight more aggressively. Sesame seeds, as well as pumpkin seeds, lentils, and garbanzo beans, are great sources of Zinc.

Your immune system is just that – a system. In addition to these immune-boosting foods, you can protect your system by avoiding harmful influences such as smoking, alcohol, inactivity, stress, and poor sleep – all of which can limit your ability to fight disease. Let's make 2017 the year of fewer sick days!