By Elizabeth Boham MD, MS, RDN
Do your daily lifestyle choices impact whether or not you catch a cold from the sneezing person sitting next to you on the airplane? Absolutely yes! You can’t stop every infection from invading your body, but you will be amazed at how much you can do to strengthen your immune system. Here are my top five tips for building a better immune system and keeping viruses and bacteria at bay this winter.
1. Move. You might not feel up to going outside for a walk in bad weather, but movement is proven to help your immune system. Exercise has been shown to improve the activity of Natural Killer cells, which are central to your immune system function. These cells are always present, ready to attack invading infections or gobble up abnormal cells in your body. You can influence how well they work, and regular moderate exercise improves their activity. Aim for 40 to 60 minutes of exercise daily. Remember, however, that excessive exercise, such as training for a marathon or competing in an intense sporting event, actually puts stress on your immune system, reducing its efficiency. Elite athletes must take extra care in supporting their immune system.
2. Eat a whole-foods diet rich in zinc, vitamin A, and vitamin C. Malnutrition is the number-one cause of immune deficiency worldwide. You might think that malnutrition is a problem only in underdeveloped countries, but actually there are significant levels of malnutrition in the United States as well. The Standard American Diet (SAD) is high in calories, but often deficient in important vitamins, minerals, and phytonutrients that are necessary for good health and a strong immune system. For my patients who frequently get infections or have a hard time getting rid of an infection, I first make sure that they are getting certain nutrients. Zinc is an important mineral for immune system functioning; good sources are animal protein, like oysters and meat, as well as some vegetable proteins, such as beans. Vitamin A is also critical for proper immune function and is found in liver, fish, cod liver oil, chicken, eggs, and dairy. Beta-carotene (found in yellow and orange vegetables) can turn into vitamin A in your body (but not everyone makes this conversion easily). Vitamin C is another important nutrient for immune function. Eating four or five cups of fruits and vegetables every day will give you plenty of Vitamin C.
3. Protect your microbiota. Every day, we are discovering more and more about our amazing microbiota. Your microbiota creates a wall of defense that prevents infections from entering your body. When these bacteria are disrupted, our risk of getting an infection skyrockets. Probiotics have been shown to strengthen the immune system; decrease the risk of intestinal infections, asthma, and eczema; and shorten the length of the common cold. So, how can we protect the trillions of good bacteria that line the surfaces of our body? First, eat a high-fiber, whole-foods diet. Fiber-rich foods (beans, legumes, nuts, and seeds) feed these good bacteria. Second, avoid unnecessary antibiotic use. Antibiotics kill off the good bacteria along with the infections they’re treating. Don’t use antibiotics for viral infections; they are ineffective and will do more harm than good.
4. Get your eight hours. How often has this happened to you: You cut your sleep short for a few nights in a row, only to find yourself sick with a head cold. Sleep is critical for your immune system. For most of us, the goal is seven to nine hours of sleep per night. Keep your bedroom dark and cool; turn off your devices (computer, cellphones, and TV) and dim the lights an hour or two before bed, to let your body know that it’s time to get ready for sleep. This will help you get the deep, restorative sleep that is so nourishing for your immune system.
5. Give your body time to rest. This is not the same thing as getting enough sleep. Resting includes taking a break from work, giving yourself time to go outside and enjoy nature, taking a yoga class, meditating, going out with friends, or enjoying a funny show. Unfortunately, with technology, many of us are finding that we can work all of the time—resist that urge! Build rest into your schedule to help you fight infections and keep you healthy all year long.