Strengthen Your Immune System With These Expert-Backed Tips

We asked a medical doctor what you can do to boost your immune system.

Mercey Livingston CNET Contributor
Mercey Livingston is a health and wellness writer and certified Integrative Nutrition Health Coach. She's written about fitness and wellness for Well+Good, Women's Health, Business Insider, and Prevention.com among others. When not writing, she enjoys reading and trying out workout classes all over New York City.
Mercey Livingston
5 min read
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Reducing stress is one way to keep your immune system healthy.

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Your immune system keeps you healthy and fights off sickness. From the common cold to the flu to COVID-19, your immune system needs to be strong enough to fight off a variety of illness, viruses and diseases.

When it comes to strengthening your body's immune defenses, there are lots of different factors at play. As tempting as it may be to pop a supplement and call it a day, there are a lot of factors that affect how well your body can fight infections and other illnesses. After all it is an entire system at work, not one entity.  

According to Dr. Michael Roizen, COO of the Cleveland Clinic, there are several major categories to consider when evaluating your lifestyle and strengthening immunity. These areas include  sleep , nutrition and supplements, exercise and stress management. Keep reading below for more information on how to optimize each of these area for your health and better immunity.

What is the immune system and how does it work?

You know your immune system is vital to keeping you healthy and fighting off sickness, but do you know exactly how it works? 

"Your immune system is what protects you from things you shouldn't have in your body whether that is cancer cells that develop inside you or bacteria or viruses or particles from the outside that cause a reaction," Roizen said. "Your body houses a number of different defense mechanisms that protect you from foreign invaders, and it all begins with your skin. Your skin has oil that stops things from getting through your skin, and you have bacteria, viruses and fungi that are healthy for you and protect you."

In addition to your skin, you also have protective mechanisms in your nose and throat. "In your nasal passages and your throat you have a lot of cilia and mucus secretions that actually contain antibodies to protect you. You have cilia in your nasal passages and lung tubes which beat like brooms to beat out anything that starts to get in," Roizen said.

Your gut also plays an important role in your immune health. "In your intestine you have a coating on your intestinal wall and a huge part of your immune system, more than 40% of your immune system is in your intestinal wall preventing things from the food you eat and the bacteria and viruses that get in to stop them from penetrating."

Now that you know how your immune system works, let's explore how you can keep it working effectively.


When you are feeling stressed or sad, it's really easy to let healthy eating fall to the wayside. But eating junk food, especially sugar, could cause more damage to you than just expanding your waistline. Your white blood cells are responsible for taking care of bad viruses and bacteria in your body, and according to Roizen, sugar is one thing that can keep them from doing their job. "Too much sugar in your system allows the bacteria or viruses to propagate much more because your initial innate system doesn't work as well. That's why diabetics, for example, have more infections," Roizen says.

A 2018 study showed that high-sugar diets were responsible for increasing inflammation and suppressing the immune system in flies. Another study showed that sugar consumption clearly affected white blood cells' ability to fight bacteria for about 5 hours after eating it -- all the more reason to watch how many sweets you're eating and look out for sneaky added sugars.


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Some supplements, like vitamin C, vitamin D and zinc may help support your immune system.

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While there is no single supplement that can magically make you immune to sickness, there are several that science has shown to be helpful for supporting immune health. Vitamin C is one of the major vitamins shown to help protect people from getting sick, and help people who are already sick feel better faster. 

Zinc is another supplement that's been flying off the shelves since the pandemic hit in 2020. And although it can't cure COVID-19, it does help the body fight off infection and may help with symptoms -- but there's really not enough research yet to say exactly how it can help.

Finally, vitamin D, once thought just to support strong bones, actually plays an important role in your immune health too. Vitamin D works by helping lower inflammation in your body and it helps activate your immune cells -- two things that are important for staying well. You can get vitamin D from regular sun exposure on your skin, and it's found in some foods, but many people need to supplement to get enough.


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Prioritize sleep for better health and a strong immune system.

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The stress and overwhelm from the global newscycle is enough to keep anyone up at night -- but now is not the time to skimp on good quality sleep. You need at least 7 hours of sleep each night, and 8 hours is even better.  

Not only can lack of sleep lead to weight gain, irritability and poor focus, it can also tank your immune system and make it hard for your body to fight off infections. If you're finding it difficult to fall asleep or stay asleep at night, try incorporating a relaxing bedtime routine that signals to your body that it's time for rest. 

According to the National Sleep Foundation, lack of sleep can lower the proteins in your body that fight inflammation and infection, making you more susceptible to illness. If there are factors outside of your control affecting your sleep, make time to take naps, which can help make up the difference. 


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Moderate, regular exercise can help support your immune system.

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While going back to the gym is a personal decision based on how much risk you're willing to take, exercise is important to prioritize for your health. Not only is it a good stress reliever and mood booster, but it can help your body fight off illness and recover faster.

The key with exercise is to be consistent and get enough each week (at least 150 minutes total per week). If you exercise very intensely (like HIIT workouts for example) you want to limit those to about 75 minutes per week total. Although the evidence is mixed, doctors like Roizen and infectious disease expert Dr. Sandra Kesh recommend not overdoing it with intense exercise right now. Strenuous exercise without proper recovery time can run your system down and make it hard to fight off infections or viruses.  

Reduce stress

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Try to manage stress with relaxing activities like meditation.

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High amounts of stress can hijack your health. But finding ways to relax, like by meditating or doing calming activities is important for your mental and physical health. Stress can lower your immune system by decreasing your white blood cell count.

Roizen agrees: "We know from studies that during stressful life events you are between 20% to 60% more likely to get a cold or the flu. In addition, stress is the leading associated factor with cancer because your immune system is decreased during stressful events and chronic stress especially," he said.

Managing stress is so important that it can actually alter your genes to be less effective at fighting inflammation. "We also know that, if you look at what stress does to your genetics, it changes the gene functioning so that you turn on things that make inflammatory proteins and you turn off genes that decrease inflammation," Roizen said.

More for your wellness:

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.