9 Ways to Boost Your Immune System

Take care of yourself -- and your immune system will take care of you.

Perhaps you're nursing a cold now -- loading up on vitamin C and zinc, maybe even sipping some warm chicken noodle soup. Taking time to recover is important to help your immune system do its work, says H. James Wedner, chief of the division of allergy and immunology at Washington University and Barnes-Jewish Hospital in St. Louis. In addition, if you find yourself frequently fighting illnesses, experts say it's worth talking to a health provider who can determine if an underlying medical cause, including an immunodeficiency, is to blame. But you don't have to wait until you're sick to boost your immune system. Here's what you can do preventively to optimize your body's defense against infection and illness.

Live well.

If you're looking for a magic bullet to boost your body's ability to fight off bugs, you might be disappointed. But if you want added motivation to improve your overall well-being, look no further: "Healthy immune systems live in healthy bodies," Wedner says. So think big picture -- from eating right and staying active to getting enough sleep. "It's important to recognize the things that are most supportive of a good immune system are a healthy lifestyle," says Dr. Fatima Cody Stanford, an obesity medicine physician at Massachusetts General Hospital and instructor of medicine and pediatrics at Harvard Medical School in Boston.

Don't rely on yogurt alone.

As much research has turned to the helpful, "good" bacteria in our gut, experts recommend consuming probiotics -- live microorganisms that may help fight off illnesses. Among the best sources for probiotics are fermented foods, such as yogurt and kefir. But if the rest of your diet is Twinkies and Oreos, or otherwise unbalanced, eating yogurt isn't going to bail you out, says Lisa Dierks, a wellness dietitian at the Mayo Clinic Healthy Living Program in Rochester, Minnesota. Ensure your diet is well-rounded: Devote half your plate to fruits and vegetables, and have a lean protein and whole grains as well. Eating foods high in antioxidants like berries can also help give your immune system a boost, as can meeting recommended levels of vitamin D.

Imbibe responsibly.

Drinking in moderation is OK. But consuming alcohol in excess can lead to the deterioration of your immune system, Stanford says. There's evidence from both human and animal research that overconsumption of alcohol decreases immune reactivity, reducing the body's ability to fight infection, Wedner says. The 2015 Dietary Guidelines for Americans advise women who choose to drink have no more than one a day; men should consume no more than two drinks a day.

Get your shots.

Immunizations are an important way to boost immunity, Wedner reminds. In addition to making sure children get recommended vaccinations, he suggests adults get an annual flu shot as well. Experts say parents should get questions about vaccines answered by health providers to separate myth from fact. The Centers for Disease Control and Prevention also provides information on vaccinations, from those that are recommended to circumstances when a person should not get a particular vaccine, such as if he or she has previously had a severe allergic reaction to that particular vaccine.

Fit in your recommended activity.

Current guidelines advise Americans do at least 150 minutes of moderate-intensity activity, like brisk walking, a week. Research shows the immune system benefits from engaging in regular physical activity, says Dr. Edward Laskowski, co-director of Mayo Clinic Sports Medicine and a specialist in physical medicine and rehabilitation based in Rochester, Minnesota. Exercise boosts the production of microphages, cells that attack bacteria that can trigger some of the upper respiratory tract infections we get, he says. And physical activity increases the circulation of many cells in our body that help fend off viruses and harmful bacteria. Just know your body's limits, and allow adequate time for recovery between workouts to ensure you're receiving the maximum boost from exercise.

Stop lighting up.

In case you need one more reason not to light up -- or to quit smoking -- here you go: "Smoking impairs our ability to fight off an infection," Stanford says. "So if we can avoid at all any cigarette smoking, [or] tobacco smoking ... that will do wonders, in terms of improving our immunity." The effect is similar to what's seen when a person drinks alcohol in excess, Wedner notes, in terms of reducing -- at a cellular level -- the body's ability to defend itself from infection. "Smoking can affect the entire body -- it's not just the lungs," he says.

Go to bed already.

A lack of sleep is frequently the culprit when people find that they're getting sick more often or unable to fend off ailments, experts say. While seven to nine hours sleep is generally recommended, work burdens or the business of life in general can significant reduce the amount of rest a person actually gets. "Sleep restores our bodies," Stanford says. Though much remains unknown about what happens when we close our eyes, that same restorative process is at work with our immune system, which can be compromised when we don't get enough rest, she adds.

Stress less.

If you're worried about strained finances or job insecurity or any number of life circumstances, it may be difficult to reduce the wear stress can have on your mind or body. But as best you're able, try to reduce your stress level, Stanford says, since stress can increase inflammation in the body. "With inflammation comes impaired immunity," she says. As with tackling stress, it can be challenging to make important changes in your life to improve overall well-being. But experts say taking steps to do so can help make all the difference in bolstering your immune system's ability to protect you -- in sickness and health.

Michael Schroeder is a health editor at U.S. News. He covers a wide array of topics ranging from cancer to depression and prevention to overtreatment. He's been reporting on health since 2005. You can follow him on Twitter or email him at mschroeder@usnews.com.