In the “new abnormal,” we don masks and gloves to grocery shop. We disinfect doorknobs and keep six feet away from people we don’t live with. Given all the focus on staying healthy, it is natural to wonder: how can I boost my immune system?

There is plenty of information on the web. A 2019 study published in Frontiers in Medicine found 185 web pages associated with the phrase “boost immunity.” Popular advice from the blogosphere is summarized below.

How much of this is based on scientific evidence vs. urban legend or marketing hype? In addition to my own research, I consulted with two experts:

Tobi Schmidt, Ph.D., Immunologist and Microbiologist, Stanford University
Edward Schneider, M.D., Professor of Gerontology, Medicine & Biology, USC

Can You Boost Your Immune System?

Dr. Schneider and Dr. Schmidt both said “no” on this one, with the exception of vaccines which do provide a boost. Dr. Schmidt added this important clarification:

“We misinterpret the word BOOST as if we could help the immune system do its job. It doesn’t need that. Instead think of what lifestyle practices you can follow to SUPPORT your immune system. ”

Okay, we’ll support our immune system — but how? Check your knowledge and then see the official answers at the end of this blog.

True or False?

You should drink orange juice or take vitamin C tablets if you feel a cold coming on.
Regular, moderate exercise reduces the risk of upper respiratory infection.
Chronic stress has a negative effect on the immune system.
Emotions such as happiness, sadness and loneliness have an effect on the immune system.
Lack of sleep affects how likely you are to get sick from a virus and how severe the symptoms will be.
Taking Echinacea when you feel a cold coming on will help reduce the symptoms.

The Official Answers

False. The effect of Vitamin C on colds has been studied for 70 years without conclusive evidence. A 2013 analysis of 29 randomized controlled trials and 11,000+ participants showed no effect on cold duration or symptoms. However, eating a variety of fruits and vegetables as part of a regular, healthy diet will support the immune system.
True. Moderate exercise has numerous health benefits. It improves immunosurveillance which is the ability of white blood cells to detect foreign microbes.
True. The effect of stress on the immune system is part of a growing field of research called Psychoneuroimmunology (PNI). Stress has a negative effect on almost all functional measures of the immune system. The biggest negative effect is on older adults and adults with chronic conditions — the same population most impacted by COVID-19.
Maybe. The connection between feelings and the immune system is an emerging part of PNI research. Dr. Schmidt explains, “Happiness and other states of being influence physiology through the endocrine and nervous systems. Both interact with the immune system.”
True. Less than 7-8 hours a sleep per night has been linked to a greater susceptibility to colds and a greater number of cold symptoms. Lack of sleep also increases the likelihood that a cold turns into pneumonia.
(Mostly) False. Studies in the New England Journal of Medicine (2005) and The Annals of Internal Medicine (2010) showed no evidence of Echinacea effecting the common cold. However, a 2015 report found the supplement “reduced risk for colds by 35%.” What to believe? Dr. Schneider explains that supplements like Echinacea work for about 10-20% of the population for reasons we don’t fully understand.

The Top Takeaway

The best way to support the immune system is through good and consistent lifestyle choices. These include nutrition, exercise, sleep and handling stress. While supplements may work for some, healthy habits are the best bet.

My husband, Rob, swears by Echinacea! (It does nothing for most.)

Click here if you want to see the research behind this blog.