The Covid-19 pandemic has created a heightened interest about our immune system and how it fights illness. And the number one question I get these days is from people who want to know if they can do anything to boost their immune system.
The answer is a complicated one, because the immune system is a collection of organs, white blood cells, proteins and other body chemicals working together to actively battle infections our bodies are exposed to.
The good news is that there is good scientific evidence that you can contribute to a healthy immune system. But it’s equally important to realize that along with evidence-based strategies, there are a lot of exaggerated and false claims out there, so it’s important to be informed with facts.
As with all lifestyle activities linked to good heath, there’s a lot of overlap of habits that are good for the immune system as well as body systems like the heart and the brain. But lifestyle activities only have a sustained impact when they’re done regularly, over time. And it’s never too late to start!
And keep in mind that you want a balanced immune system—not one that’s working in overdrive. A balanced system fights infection, but too sensitive of a system can result in problems, including autoimmune diseases where the immune system overreacts and attacks healthy tissue in the body.
Here are the top, evidenced-based ways to optimize your overall immune response:
Make sure all of your vaccinations are up to date.
While all thoughts are on Covid-19 vaccinations—two shots plus a booster for optimal protection—it’s important to make sure all of your vaccinations for diseases are up to date.
Make sure your annual flu “booster” is up to date (it’s only maximally effective for about 6 months). And while we’re all attentive to our children’s series of vaccines, many of us don’t bother to check on vaccines like polio, diphtheria, pertussis (whooping cough), and tetanus. The protection doesn’t last a lifetime, so check with your primary care doctor for boosters that are important for you. And depending on your age and health status, vaccines for shingles, hepatitis, and pneumonia are also readily available.
Meet your daily nutrient requirements.
The best boost for a solid immune system is a nutrient-rich, balanced diet. Forget any promoted “immunity diet,” which doesn’t focus on overall eating but rather specifics nutrients. Whether you’re a plant or animal eater, carb craver or fat lover, choose a balance of nutrients that includes plenty of colorful fruits and vegetables, lean proteins, whole grain starches, and heart health fats. A great example of this is the Mediterranean diet.
A lot of the confusion and misinformation about how food contributes to immunity comes from studies showing how a documented deficiency in a particular nutrient can have a negative impact on immune factors. When the deficiency is corrected to normal levels, immunity is restored. The unknown question is whether boosting that nutrient further also improves an immune response. It’s not a case of “more is better."
And while you want to avoid specific supplements that claim to “boost your immune system,” if you have deficits in your eating, due to food preferences or disease-restrictions, consider a single multivitamin-mineral supplement with 100 percent of daily requirements to support, not replace, foods. Always check with your doctor first to make sure you’re making the right choice for you.
Get more activity in your day.
Physical activity can sometimes boost immunity, but a lot depends on the intensity and duration of the activity—and always depends on regular participation. Moderately intense activity (like brisk walking, biking, yoga, or lifting weights) has been shown to increase blood markers of positive immune activity. So with your doctor’s OK, boost your activity to include at least one of the triad of exercise: cardio (like walking), strength training (like weight lifting), and flexibility (like yoga). And it’s fine to add more activity, but science also shows that too much exercise can lower your immune response, so listen to your body! When you’re done exercising you should feel good, not overwhelmingly exhausted or in pain.
Get a good night’s sleep.
It’s clear that sleep problems can reduce your immune response, whether it’s not enough or of poor quality. Studies show that a restful sleep boosts the release of inflammation-fighting chemicals to help fight infections. And poor sleep can make you more vulnerable to getting sick, or can result in it taking a longer time to recover. Sleep is also necessary to the normal functioning of your circadian rhythms—the normal ups and downs of body hormones that support normal daily function.
And chronic lack of sleep increases your risk of cardiovascular disease and obesity—both which can contribute to a compromised immune system.
Most adults need about seven to eight hours of sleep regularly.
Manage your stress.
Some studies indicate that the biological impact of both short- and long-term stress is connected to the immune system. While a key hormone released during stress—cortisol—can influence some parts of the immune system, there’s a lack of clear cut information about the direct impact of cortisol and other stress markers on overall changes in immune responses. That’s because it’s hard to measure both stress and immune function in standardized scientific studies. But the good news is that for healthy people, the immune system is remarkably flexible and capable of substantial changes without compromising a balanced immune response. But age and disease can modify the ability to mount a robust immune response under stress.
And stress can negatively impact the ability to make lifestyle changes well documented to impact the immune system: following a nutrient-rich diet, increasing physical activity and getting a good night’s sleep. So focusing on ways to reduce stress still remains a key priority for optimizing your immune system.
Madelyn Fernstrom, PhD is NBC News’ health editor. Follow her on Twitter @drfernstrom.