“Reinforce and Boost Your Immune System” promised the ad splashed across two pages of a local newspaper. There were products galore! Mushroom extracts, probiotics, collagen supplements, exotic oils, bee propolis and various “kefir-kombucha fermented blends.” No direct reference is made to COVID-19, but the implicit message is clear. If somehow we can boost our immune system we will be in a better position to ward off this nasty virus. Sounds good, but the truth is that “boosting the immune system” is a scientifically meaningless claim. So is “supports immune function.” These are marketing terms, not scientific ones.
The immune system is not like a muscle the size of which can be boosted by exercise. It is a highly complex system of cells, tissues, organs and a host of chemicals they produce to help the body fight infections and other diseases. There are two basic components to the immune system, innate and acquired, sometimes called adaptive. The innate system swings into action with a variety of cells and chemicals as soon as the body is attacked by a foreign substance, be it a bacterium, a virus or a toxin. The reason we sneeze and cough and have a runny nose when we catch a cold is that the body is trying to expel the intruding virus. Our throat may become inflamed because blood vessels dilate allowing white blood cells to rush to the scene to engulf and neutralize the invader. That’s our innate immune system in action.
But thanks to the acquired or adaptive immune system, we never catch the same cold twice. That’s because exposure to an intruder stimulates the immune system to produce antibodies, special proteins that recognize the intruder on a subsequent exposure and neutralize it. This is an extremely oversimplified view because there are dozens of different white blood cells, numerous antibodies and all sorts of messenger chemicals involved in the proper functioning of the immune system. It is true that a poor diet, lack of exercise, impaired sleep, stress and aging can diminish the immune response, but this cannot be remedied with supplements, juices, chiropractic adjustments or homeopathic treatments.
Even if immunity could be boosted in some simple fashion, such an intervention could have negative consequences. An overactive immune system can attack healthy tissues, which is exactly what happens in “autoimmune” diseases such as arthritis and lupus. There is increasing evidence that conditions such as diabetes and heart disease are associated with low-grade chronic inflammation that is a result of unwelcome immune activity. Basically, we want our immune system to protect us from foreign substances, but we do not want it to go into overdrive and attack healthy tissues. Luckily, when in a healthy state, our bodies manage this well.
In fact, one of the most fearsome complications of COVID-19 is a “cytokine storm” which is a hyperimmune reaction. Cytokines are molecules that are released when the body senses an invader but if they become too abundant, the immune system may not be able to stop itself. Immune cells spread beyond infected body parts and start attacking healthy tissues, gobbling up red and white blood cells and damaging the liver. Blood vessel walls open up to let immune cells into surrounding tissues, but the vessels get so leaky that the lungs may fill with fluid, and blood pressure drops. Blood clots throughout the body, further choking blood flow. When organs don’t get enough blood, a person can go into shock, risking permanent organ damage or death.
The question to ask when a claim is made about boosting the immune system, is what exactly is being boosted? White blood cells? Which type? Macrophages? Eosinophils? Killer T cells? Helper T cells? B cells? Lymphocytes? Chemical messengers? Which ones? Interferons? Interleukins? Cytokines? Tumour Necrosis Factors? How about antibodies? IgG? IgA? IgM, IgE or IgM? Where are the studies that show that taking any supplement, be it kombucha or vitamin C or green tea has any effect on any of these parameters? There are none! The exception may be vitamin D with low levels being linked with a higher risk of respiratory infections and the development of autoimmune diseases.
Oh yes…there is one way that we can boost immunity. Vaccination! That actually can be shown to produce antibodies against invading organisms.