Possible Insight

I’ve been taking quercetin for a few months now and thought I’d report on my experience. As you can see from the Wikipedia link, quercetin is believed to have anti-inflammatory and anti-tumor properties.  This is not why I’m taking it.

Rather, I had a record number of colds this season.  4 major ones from Thanksgiving to mid-Feb.  I have been training unusually hard for the last year and an increased incidence of upper respiratory infections (URIs) is a known problem for endurance athletes. A little research turned up this article where quercetin reduced the incidence of URIs in marathoners.

So I ordered a couple bottles of this and started taking 2 capsules twice daily. Note that this product also has bromelain in it, an anti-inflammatory added to quercetin when treating for allergic rhinitis.  Seemed like that could be part of my problem… in for a penny in for a pound.

I noticed four potential effects.

• I stopped getting colds. Of course, this could be simply timing of the cold season.
• My cardiovascular fitness went up. Over two and a half months, my output at a given heart rate went up by 5%. My heart rate a given output went down 7-8 bpm. Of course, this could simply be the result of not having a cold. The evidence for quercetin improving athletic performance is mostly negative.
• I appeared to have gained some muscle mass. From the combination of my weight going up and my waist measurement going down, I estimate I gained about 3lbs of muscle mass.  Of course, this could be explained by the fact that I was able to start doing kettlebells seriously again because a shoulder injury has mostly healed.
• I seemed to require a little less ibuprofen to keep minor injury pain in check. Quercetin may have some anti-inflammatory effect. Of course, bromelain inhibits CYP2C9 activity in the liver which may slow down ibuprofen metabolism. So the serum level of ibuprofen may have been the same at the lower dosage due to inhibition rather than direct anti-inflammatory effect.

Your mileage may vary.