Nutrition for Immunity
By Sarah Martin, RDN


As we move into flu season, it’s worth taking a moment to think about the foods you’re putting into your body. Are you choosing foods that can keep you healthy? Eating nutritious foods doesn’t guarantee that we’ll never get sick, but they do help our immune system function optimally to fight infections and heal our bodies. 

Our immune system is a complex tangle of hormones, macrophages, cytokines, antibodies, and chemical messengers. Much like our other body systems, our immune system relies on a unique blend of nutrients to keep it functioning well. There are many lifestyle factors that impact our immunity, including adequate sleep, exercise, stress management, hygiene, and of course, our diet! It’s wise to avoid unhealthy behaviors like smoking or drinking excessively, as these may suppress our immune system. 

Many nutrients are involved in proper immune function, though a few are particularly important. You’ve likely heard about the benefits of vitamin C in fighting off illness. Some people binge on this vitamin supplement when they feel a cold coming on, but you can get plenty from colorful fruits and veggies like bell peppers, oranges, or broccoli. Vitamin C works by driving the production of white blood cells and antibodies to fight infection, as well as collagen to heal tissue. 

Our immune system also relies on a combination of nutrients like vitamin D, zinc, vitamin A, selenium, and B vitamins to help modulate our immune response. Be sure to soak up some sun to boost vitamin D levels and consume vitamin D-fortified dairy or dairy substitutes. Zinc comes from meat, grains, and beans, and vitamin A is found in red, orange, and yellow produce. Selenium is found in meat, eggs, and grains, though the better-known source is Brazil nuts, and B vitamins are high in a wide range of foods including meat, grains, nuts, and beans. You can see that the key to giving your body all the nutrients it needs is to eat a variety of foods! 

Our bodies also produce other chemicals which impact our immunity. One is melatonin. If you’re thinking that melatonin is a sleep hormone, you’re right! But having adequate melatonin is also vital for immune function. Maintaining a regular sleep schedule can help you sustain healthy melatonin levels.

Our bodies use water to flush out toxins and waste, which helps all of our systems to function properly. For this reason, it’s good to stay hydrated! Try keeping a water bottle with you throughout the day. You can flavor it with fruit or herbs. Frozen berries work well, and mint or basil add a nice zesty flavor.  

This fall nourish your immune system with colorful produce, whole grains, mixed protein, and low-fat dairy to be sure you’re giving your body all the nutrients it needs. Remember that other lifestyle factors are also important — it’s best to take care of your body in all ways! Get enough sleep, maintain some level of exercise, and practice good hygiene to give yourself a chance to fight off any traveling bugs. Your body will thank you!