Quercetin is one of the most common flavonoids found in edible plants, with especially high levels occurring in capers, elderberry juice, cilantro, onions, teas, and kale.

Like raw powdered curcumin, quercetin is poorly absorbed and is mostly insoluble in water. Food-based quercetin is better absorbed than powdered forms. Mixed with extra-virgin olive oil or coconut oil, it is somewhat better absorbed.

Thus far, there is no commercially available form of nanosized quercetin, so the best solution is to mix it with coconut oil or extra-virgin olive oil.

Like curcumin, quercetin is a powerful anti-inflammatory, antioxidant, antiviral, neuroprotectant, and anticancer compound with a high safety margin. And like curcumin and hesperidin, it inhibits a number of cell-signaling pathways that fight cancer.

Quercetin inhibits cancer development, progression, proliferation (tumor growth), invasion of surrounding tissues, and metastasis — that is, it impedes cancer at all stages, and does so without the toxicity of chemotherapy.

Usually, chemotherapy does not differentiate between normal cells and cancer cells — it poisons them all. And chemotherapy and radiation treatments induce intense inflammation in the body, which is — ironically — the main cause for cancer development.

That explains why there is such a high incidence of secondary cancers (as well as other health problems) in long-term cancer survivors. These are distinct cancers caused by the treatments themselves.

Using natural anticancer compounds such as quercetin, curcumin, and hesperidin can prevent the development of these secondary cancers.

Despite these benefits afforded by natural compounds, oncologists rarely use them — mostly because of powerful influence by pharmaceutical companies on medical bureaucracies.

What oncologists fail to appreciate is that 80 percent of all chemotherapy drugs are derived from microorganisms or plant extracts.

The problem is that the pharmaceutical manufacturers chose the wrong natural plant extracts — the ones that are highly toxic to the entire body.

On the other hand, most natural anticancer compounds are highly selective — killing cancer cells, but protecting normal cells.

Newer studies are finding that traditional cancer treatments are not only extremely harmful, but rarely work against cancers that have already spread (metastasized).