Quercetin?

[Hypnogal]

I am considering taking Quercetin for my allergies...but I'm not sure if I should.  My concern is that it is not why you might think.  The fact that it is "natural" and a natural blood thinner does not concern me.  I am worried about hormonal effects from this bioflavenoid.  I know when I take soy -I have extreme hormone issues - it is an ISOflavenoid.  Quercetin is a BIOflavenoid - and in its normal levels in onions for example, not a problem, but this is a high concentrated dosage.  I tried it once and had what I felt was a drop in estrogen levels - ?  Is this possible?  Does it have hormonal influences?  I know it is a natural antihistamine / anti-inflammatory.  But is it worth risking unknown effects of ?

[National Jewish Health]

There are reports of Quercetin causing DNA damage and exhibiting carcinogenicity.  The following is from a report on the treatment of laryngeal cancer which refers to its affinity for Type II Estrogen Binding Sites.

In another report of "Quercetin interaction with EBS's, a biochemical assay, there were a large number of type II EBSs which could be involved in the anti-estrogen action."

These reports suggest an anti-estrogen effect.  Also, given the effects on DNA, it is probably not worth the risk.

[WEGO_Dan]

Hi.  I'm not sure whether you're considering taking quercetin on an "as-needed" basis or if you're thinking about taking daily supplements, but given that you have "extreme hormone issues," I recommend you avoid quercetin supplements, at least in the latter case.  The risk-reward tradeoff simply doesn't seem favorable.

Quercetin is, as far as I know, proven effective as an anti-inflammatory and, to a lesser degree, as an antihistamine.  To my knowledge it has not, however, been shown to be any more effective than other anti-inflammatories or antihistamines, such as Benadryl or Claritin.  

Quercetin, however, has been implicated as an endocrine disruptor.  Studies indicate that, along with other flavenoids, quercetin may alter thyroid function.  I've also read that it mimics estrogen, which can obviously affect your natural estrogen levels.

I'm a big fan of "natural" remedies, but because a) you have hormonal problems; b) quercetin may exacerbate hormonal problems; c) quercetin is not a silver bullet for allergies; and d) there are relatively less risky alternatives, from conventional drugs to allergen avoidance, I just don't see how taking a quercetin supplement can be justified.

I'm not aware, incidentally, of any potential problems with quercetin at normal levels found in foods.  It's just the long-term use of a quercetin supplement that prompts me to caution you about this.

By the way, what kind of allergies do you have?

Dan -- www.wegohealth.com