5 ways to build a stronger immune system

Our world is full of viruses and bacteria. The only way to avoid them entirely is to live in a sterile bubble. But who wants to do that? A better and more realistic bet: Boost your immune system so your body can protect itself against the germs that could make you sick.

The best way to boost your immunity is to get recommended vaccines. That includes the flu and COVID-19 shots as well as the pneumococcal vaccine if you’re over 65.¹ Beyond that, it’s all about focusing on everyday things that can keep your immune system thriving.

With cold and flu season here, now is the perfect time to make sure your daily habits are keeping you healthy and strong. Our fun five-day immune-boost challenge can help. It works like this:

Below are five simple habits proven to help protect you against illness. Pick a day to begin the challenge. On Day 1, try a new tip. On Day 2, add a second tip to your daily routine. Then keep going until you hit Day 5. At the end of the challenge, you’ll have five new habits that can help keep you healthy this fall, winter and beyond. Plus, they’ll support your immune system’s healing powers if you do catch a bug. Let’s begin.

Day 1: Wash your hands the right way

This is really your first line of defense. Washing your hands regularly and thoroughly lowers the number of germs it must fight off. Here’s when it’s most important to scrub up:

• Before and after preparing food or eating
• Before and after being in a public place or touching things that lots of other people have touched (think: shopping carts, door handles, gas pumps and the like)
• After using the bathroom, caring for someone who’s sick, blowing your nose, coughing or handling garbage

But don’t rush it or you won’t do much good. The best way to wash your hands free of the most germs is to:

• Wet them with clean running water.
• Lather them with soap by rubbing them together for at least 20 seconds. Be sure to get the fronts and backs and between the fingers.
• Rinse your hands well under clean water. Dry them with a clean towel.

You also should keep a small supply of alcohol-based hand sanitizer close by, says Jeffrey Landsman, M.D., of Mercy Medical Center in Baltimore. Dr. Landsman is board-certified in family, lifestyle and geriatric medicines. He also suggests stashing a container in your car for backup. “And try to avoid touching elevator buttons, escalator handles, handrails and doorknobs,” he says. Countless other hands have already touched them. Use your elbow or sleeve instead.

Day 2: Eat different fruits and vegetables at every meal

“The more colorful the fruits and vegetables you consume, the greater variety of health-promoting nutrients you get,” says Jeffrey Landsman, M.D., of Mercy Medical Center in Baltimore. Dr. Landsman is board-certified in family, lifestyle and geriatric medicines.

For example, you’ll get plenty of vitamin A in cantaloupe, sweet potatoes, spinach and red peppers. Vitamin A plays a key role in the growth and function of immune cells that fight off viruses.²

And vitamin C — found in oranges, strawberries, broccoli and bell peppers — helps heal wounds and repair tissues all over the body. It may also help shorten the length of a cold by up to 1½ days.³

To get a jump on having brightly colored produce at every meal, steal Dr. Landsman’s trick for breakfast: He often has a smoothie made with a frozen banana, blueberries, strawberries, spinach and almond milk.

Day 3: Take a walk

Exercise can boost your immunity. But don’t push your body too hard. Try to regularly get up to 45 minutes of moderate-intensity exercise to strengthen your body’s natural defenses. That’s especially true for older adults and people who have a chronic condition such as diabetes or heart disease.⁴

So what is moderate exercise? Here are some things to try:⁵

• Brisk walking
• Biking
• Swimming laps
• Doing water aerobics
• Walking stairs
• Washing your car
• Gardening
• Raking leaves
• Dancing

Dr. Landsman’s personal strategy: If he’s not playing tennis, he’ll ride his home exercise bike for 20 to 30 minutes after work.

Day 4: Make sleep a priority

Too often, sleep takes a back seat to everything else in life that we need to do. And sometimes, worrying about those to-dos keeps us up at night. Whatever is to blame, lost sleep takes a toll on the immune system. Too little sleep can increase your risk of infection and of developing conditions like heart disease.⁶

For today’s immune-boosting challenge, focus on putting sleep first. Ditch the late-night emails and chores, Dr. Landsman advises. Turn off electronic devices such as your TV and smartphone at least an hour before bedtime. (The light from screens can keep you up.) And go to bed at a reasonable hour — a time that lets you get between seven and nine hours of sleep.

Day 5: Take time to decompress

A little stress is normal. In fact, it can even ramp up your immune system and get it ready for a fight. But stress that goes on without relief can weaken your immune system. For example, it can lower your number of immune cells that fight viruses.⁷ So try to find a little time every day to lower your stress levels.

Looking for some new ways to ease stress? Try mind-body therapy (MBT) such as meditation, yoga, tai chi or qi gong. Studies show MBT can help improve coping, quality of life and well-being.⁸ Doing MBT regularly can lower chronic inflammation. It can even improve how well your immune system responds to vaccinations.⁸ Maybe start by doing an online yoga video — there are options for all levels. Or download a meditation app on your smartphone. Bonus: Using the app may improve the quality of your sleep as well, Dr. Landsman says.

¹Centers for Disease Control and Prevention. Immunization Schedules: Table 1. Recommended Adult Immunization Schedule for ages 19 years or older, United States, 2021. February 12, 2021. Accessed June 13, 2022.

²Huang Z, Liu Y, Qi G, et al. Role of vitamin A in the immune system. Journal of Clinical Medicine. September 2018, 7 (9): 258.

³Academy of Nutrition and Dietetics. How vitamin C supports a healthy immune system. EatRight.org. March 30, 2021. Accessed June 13, 2022.

⁴Simpson RJ, Campbell JP, Gleeson M, Kruger K et al. Can exercise affect immune function to increase susceptibility to infection? Exercise Immunology Review. 2020; 26: 8-22.

⁵Cleveland Clinic. What does moderate exercise mean, anyway? A guide to calculating your heart rate. October 23, 2020. Accessed June 13, 2022.

⁶Centers for Disease Control and Prevention. NIOSH training for nurses on shift work and long work hours. March 31, 2020. Accessed June 12, 2022.

⁷Segerstrom SC, Miller GE. Psychological stress and the human immune system: A meta-analytic study of 30 years of inquiry. Psychological Bulletin Journal. July 2004; 130(4): 601-630.

⁸Morgan N, Irwin MR, Chung M, and Wang C. The effects of mind-body therapies on the immune system: meta-analysis. PLoS One. July 2, 2014; 9(7): e100903.