Fight COVID: Boost Your Immune System Naturally

Rania Dempsey, MD, MS | November 4, 2020

While a healthy lifestyle is not a substitute for getting fully vaccinated against COVID, healthy lifestyle choices decrease the likelihood of contracting COVID in the first place, or of developing severe disease if you do get sick. The best way to boost your immune system naturally? Follow these healthy lifestyle habits:

Get enough and restful sleep.

Most adults need 7-9 hours of sleep each night, but in the US one in three adults gets six hours or fewer. Adequate rest is extremely important for healing, cell repair, and immune function. Unfortunately, the more sleep deprived you are, the less able you are to perceive fatigue, and many people believe they can get by with less sleep than they actually need.

To get a good night’s sleep, avoid caffeine in the afternoon, and stay away from alcohol and food for 3 hours before bedtime. Getting exercise and plenty of sunshine during the day also helps you sleep better at night.  And, though falling asleep in front of the TV is a favorite of many for winding down, the blue light from screens (such as TVs, phones, and computers) actually interferes with sleep cycles, so it’s best to turn off screens at least one hour before bedtime. To help you relax, try substituting a cup of hot tea and deep breathing or mindfulness meditation before bedtime instead.

Eat your fruits and veggies.

Diets rich in fruits and vegetables are associated with lower disease risk overall, and high fruit and vegetable intake enhances immune function according to a meta-analysis published in 2018. Fruits and vegetables are loaded with nutrients and antioxidants that boost the immune system and help fight off disease.

Choose a wide variety of brightly colored fruits and vegetables, including dark green leafy vegetables, cruciferous vegetables (such as broccoli, kale, and cabbage), berries, kiwi, spinach, sweet potatoes, and citrus fruits.

Limit processed foods.

Whether processed foods directly impair the immune system or just crowd out other healthy foods that boost immunity isn’t entirely clear. But diets high in processed foods such as refined sugars, white flours, and processed meats can lead to disturbances of healthy intestinal microorganisms (“good gut bacteria”), leading to chronic inflammation in the gut and impaired immune function.

Choosing foods as close as possible to the form they’re found in nature (think whole apple instead of apple juice or fruit snacks) is a great way to make sure you’re eating whole, unprocessed foods as much as possible.

Get moderate exercise.

There is strong evidence that regular exercise is good for you. In addition to reducing the risk of multiple diseases (including cardiovascular disease, erectile dysfunction, stroke, some cancers, and dementia), regular exercise improves mood, and helps you sleep better. Regular exercise has been shown to enhance immune function, and moderate exercisers reduce their risk of catching a common cold by one third compared to sedentary people.

The good news is you don’t have to be an ultra-endurance athlete to reap the benefits of exercise—in fact extreme training may decrease immune function. Current guidelines recommend 30 minutes a day of moderate intensity physical activity most days of the week, but even as little as a brisk walk 10 minutes a day has been found to improve health.

Mind your substance use.

It is well documented that tobacco suppresses the immune system and impairs the body’s ability to fight off infection and disease, so quitting smoking is one of the best ways to strengthen your immune system. And while it’s alluring to think that vaping may be a safer alternative, a recent study found that young people who vape are at higher risk of COVID-19 infection than those who don’t.

Alcohol is another widely used substance that can suppress immune function, particularly at high doses. If you drink alcohol, limit it to no more than 1 drink per day for optimal immune function.

Connect with others.

Making meaningful connections with other people is an often overlooked but very important influencer of health. People who connect with others through strong relationships and a good social network have stronger immunity than those who feel isolated.

Unfortunately, connecting through social media does not result in the same positive effects as in-person connections. Connecting “live” can be difficult or impossible in this pandemic environment, and social isolation is increasingly common, but there are ways to connect meaningfully that go beyond liking or retweeting a friend’s post. Pick up the phone, write a letter, arrange to meet at a park for a walk, or join a live video-group book club or discussion group. During this time when face to face contact is limited, it’s even more important to seek out avenues for meaningful conversation and connection with others.

Spend time in nature.

Emerging research shows that spending time in nature enhances the immune system and protects against a wide range of diseases, including depression, diabetes, ADHD, cardiovascular disease, cancer, and many others. Time in nature allows us to slow down, and may also result in physiologic benefits such as increased vitamin D production and improved oxygen availability from exposure to sunlight and trees.

What if you live in an urban area that doesn’t have easy access to mountains or hiking trails? Just sitting on a park bench for 15-20 minutes per day was found to boost immunity (though walking or hiking in nature is even better). If you don’t have time to get outside every day, even a single longer session outside on weekends is beneficial.

Manage your stress.

For many people, the COVID-19 pandemic has brought stress levels to a new high. Worries over job security, health, and ever-diverging viewpoints on how to stay safe in these times has led to uncertainty and anxiety that has lasted for months. Unfortunately, the human stress response was meant to endure short-term, acute stressors. When under stress, the body goes into “fight or flight” mode, which means it shuts down everything that is not immediately essential, including the immune system. Facing chronic stress for months on end, the body stops investing in long-term health such as healing, growing and building the immune system.

Managing stress requires a two-pronged approach: First, try to decrease or eliminate any stressors that are within your control (such as overcommitting to too many activities that leave you spread too thin, or spending time with toxic friends). Second, learn and embrace strategies that help you cope with stressors that are outside of your control (such as job loss or health issues). Staying present through mindfulness meditation and breathing exercises can help reduce feelings of anxiety and stress, and there are many free resources available online to teach these strategies. Many people also find they benefit from consulting a mental health professional.

Whether you are already following some of these lifestyle strategies or they are all completely new to you, don’t get caught up in thinking you have to do everything perfectly to see any benefit! Lifestyle changes are best made at a pace gradual enough that change is sustainable, and that pace may be different for each person. Choose one area to start with, set small goals, and build on successes. Remember, lifestyle changes don’t require perfection, just progress!