In an age of health hyper-awareness, society is coming round to the notion of natural interventions to prime our immune system. The past year has brought attention to our vulnerabilities and reminded us of the hidden invaders that can occupy our bodies seemingly undetected.
Many different natural health products and supplements have exploded into existence in the past couple decades. The dietary supplement industry, as of 2016, was valued at $133 billion USD worldwide, and is expected to hit upwards of $220 billion by 2022. It is important that a high degree of scientific scrutiny follow hand-in-hand with these new treatments in order for us to understand their safety and efficacy. For immune-supporting treatments, that has evidently never been more true.
Zinc is one such supplement that has gathered greater attention this year after research came to light showing a direct correlation between zinc deficiency and worsened COVID-19 outcomes.
While this came as a surprise to some, the research around zinc’s role in immune regulation has been recognized for years, with deficiencies shown to play a role in immune dysfunction, hair loss, skin lesions, poor wound healing, and mental sluggishness. Fittingly, zinc deficiency is more commonly found in the elderly and those with chronic diseases; the two groups we have come to learn are highly vulnerable to COVID-19.
As a brief overview, zinc is a micronutrient and mineral required by our bodies to carry out a number of different functions. The amount needed to maintain these functions is 11 and 8 milligrams/day for adult males and females, respectively, according to the NIH’s recommended dietary allowance (RDA) (same reference as above). The benefits of zinc for bolstering the immune system arise once it has been absorbed in the gut, filtered through the liver, and sent out through our blood to reach the various organs and tissues it will aid. This final step of entering into the cells is where our zinc sidekick makes its grand entrance.
Quercetin is a bioflavonoid found in a wide variety of plants and their fruits, most commonly in red onions and apples, and is commonly used as a supplement for its anti-allergy effects. Interestingly these anti-allergy properties, which are due to quercetin’s ability to block histamine release (just like your over-the-counter anti-histamines), are just one of the many benefits that have been studied. Another benefit may be its ability to help carry zinc into our cells.
Like the bouncer who limits people coming into the night club (remember when those used to be a thing?), there are proteins in the fatty barrier that surround each cell whose sole purpose is to control the flow of zinc in and out of the cell. Without these proteins, zinc would have no way to pass this barrier, as zinc’s electric charge is repelled by the fatty cell membrane.
One other way that zinc appears to get into the cell is by attaching to other molecules, such as quercetin. This partnership of molecules changes the properties of zinc, and makes it more compatible with the cell membrane so it can pass on through. In fact, researchers found that adding quercetin to cells with zinc increased the concentration of zinc in the cell, and found that this was not due to increased entry through the transport proteins described above (https://pubmed.ncbi.nlm.nih.gov/25050823/).
Zinc and quercetin both have immune-supporting benefits on their own (ref. 1, ref. 2, ref. 3, ref. 4), which explains some of the health benefits of foods rich in these molecules. However, there is strong reason to believe that these molecules can act synergistically when used in tandem, exerting greater effects than when either nutrient is used alone.
With a societal awareness and increased focus on preventative medicine it is perhaps these small, simple, and less celebrated (not to mention less profitable) measures that are needed to keep our immune system strong. Provided the right nutrients, sleep, exercise, and exposure (to different people and environments), our immune system can be trained to better protect us like soldiers going through combat training.
Infectious pathogens have been around much longer than us, and they are here to stay. Our future will depend on our adaptation, and not the removal and sanitization of our planet. The sooner we come to terms with this reality, the better off we will be.