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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Bioflavonoid Quercetin has Anti-Cancer Effects

Updated: October 18th, 2018

Quercetin has been around for some time as it is a naturally occurring compound found in the peels of citrus, capers, certain herbs, onions, and grapes**. Quercetin is also found in the Chinese Scholar tree, one of the 50 fundamental herbs used in Traditional Chinese Medicine.

Quercetin has some interesting and fairly potent anti cancer effects. First, it has anti inflammatory effects.  We now know that cancer development and also cancer progression both rely on low grade inflammation in the body.  Inflammation that is low grade may not be visible to the naked eye.

Our bodies and those of our loved dogs are constantly barraged by a host of microscopic, damaging substances daily.  This creates inflammation.  Excess fat in the body creates inflammation.  A diet too rich in certain fats (omega 6 fatty acids) and lacking in others (omega 3 fatty acids) creates inflammation.  Smoke, pesticides and herbicides, inhaled exhaust can all create this type of inflammation.  Finally, cancers themselves created inflammation.

Quercetin is able to partially block the very same enzymes that are targeted when vets and oncologists use anti inflammatory medication as a part of metronomic chemotherapy. This kind of chemo is low dose, and may help to help lessen the blood flow that helps feed developing or spreading cancers.

This compound also has been shown to attack human breast cancer cells (in a test tube) in a way that is similar to some of the new dog cancer drugs, Palladia and Kinavet K-1 (masitinib).

An injected form was found to shrink sold tumors in mice.  But what about taking it as a pill?  This works too, but we need to protect it from being broken down so it gets in the bloodstream (this is the method used in Apocaps, and it was for these reasons that rutin, a rich source of quercetin, was included in the Apocaps formulation.).

So how can we use this interesting substance?

First, we need to be sure that we are not creating anti oxidants which could interfere with some chemo drugs and other helpful strategies (these are outlined in the Guide).  If we use larger doses of quercetin, we can overcome this effect.

Secondly, we should think of quercetin for tumors of the stomach or intestine which will get the highest dose of a tablet taken by mouth.  Quercetin does have other uses, but this is one easy one to remember.

And it has been shown to be safe. 🙂

All my best

Dr D

**Note that onions and grapes may create toxic reactions in dogs.

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  1. […] Demian Dressler, the well-known Dog Cancer Vet, explains that low dose chemotherapy treatment (metronomic chemotherapy) targets certain enzymes […]

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