Containing Coronavirus: Let’s Talk Quercetin

The race is on–the race to find the small molecules that might fight COVID-19.  Canada’s Dr. Michel Chrétien, brother of a former Prime Minister, is hedging his bets on quercetin, small molecules abundant in plants. Should you, too, hedge your bets?

For almost a decade now, I’ve been immersed in phytonutrients, the bioactive molecules that plants make, often to fend off their own enemies.  And for years, quercetin’s been in the spotlight–“a significant anti-inflammatory and anti-cancer agent… shown to have protective properties against a number of diseases… .”

It’s also been successful at treating Ebola and Zika viruses in animal models, Chrétien recently told the Canadian Broadcasting Corporation.  He and his colleague, researchers at the Clinical Research Institute of Montreal, are now planning clinical trials to test quercetin in humans with COVID-19.   They think that the molecules block entry of the virus into cells. 

So where can you get some of these small molecules?  I’m hedging my bets on one cheap plant food.  Recent research funded by the USDA found that quercetin is highly bioavailable from onions–that is, it readily gets into your blood, especially if you eat onions along with a little healthy fat.

Again with the onions!, all you fans of my diet and cancer blog are likely yelling. Yes, once again, here’s a brief primer on how to get the most out of the sacred plant.


Choose small red or yellow onions–the kinds grown in northern soils for long winter storage.  Unlike summer’s fresh bulbs and Georgia’s sweet Vidalias,  those onions are rich in stinky sulfurs, another group of health-promoting molecules.

Cut onions and let them sit a half hour before cooking. That will give the sulfurs time to develop.

Peel onions oh so gently. Like many phytonutrients, quercetin concentrates in the plant’s outer layers.

Cook onions a bit to release quercetin from the plant matrix.  I’m a fan of the saute-steam. First, saute onions briefly with spices, such as this pot of gold. Then throw a tad of water into the pan, cover immediately, and steam the onions quickly.  Quercetin is water soluble.

Save peels, and make a quercetin-rich broth.  Boil peels, onions and other sources of quercetin:  juniper berries, dried oregano, celery.  Discard overcooked plants, and use the broth to make soups, stews, beans, grains. (Celery’s got another small molecule that’s promising in the COVID-19 fight.  More on that coming soon.)

Finally, if you, like many, struggle with peeling onions, here’s my simple secret:



The race is on.  Submit your best recipes for a tasty quercetin broth in the Reply section below–and let’s beat this bugger.






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