Quercetin Boosts Immunity and Helps Maintain Mental Performance

In February 2007, researchers at Appalachian State University announced the results of a clinical study on the flavonoid quercetin at the Southeastern Regional Meeting of the American College of Sports Medicine, held in Charlotte, N.C. Their results showed that quercetin may help reduce illness and maintain mental performance in physcially stressed test subjects. I’ve written about the antioxidant quercetin in a previous article as an alternative to dichloroacetate (DCA), a chemotherapeutic agent that was recently shown to selectively inhibit cancer cell growth in lung, breast and brain tumor cells grown in culture and lung tumors grown in immunocompromisted rats.


Quercetin is a polyphenol, one of a number of water-soluble plant pigments called flavonoids (meaning class of plant secondary metabolites known for their antioxidant activity) that are largely responsible for the color of many flowers, fruits and vegetables. High concentrations of quercetin are found in apples, onions, tea and red wine [1]. Other sources of quercetin include olive oil, grapes, broccoli, cauliflower, cabbage, dark cherries and dark berries such as blueberries, blackberries and bilberries. The average U.S. citizen eating a normal, healthy diet including fruits and vegetables consumes approximately 25-50 mg of quercetin/day. Quercetin and other flavonoids (also referred to as bioflavonoids) cannot be produced in the human body.

Alternative to Dichloroacetate

It’s been three months since an article on dichloroacetate (DCA), the chemotherapeutic agent that selectively inhibits cancer cell growth in lung, breast and brain tumor cells grown in culture and lung tumors grown in immunocompromised rats, was published on Highlight HEALTH. Since then, thousands of people have read the article. Indeed, the blogosphere has been buzzing about DCA, unfortunately focusing on a conspiracy theory accusing big pharma of suppressing a cure for cancer instead of recognizing the study for what it is — a preliminary study in cell culture and rats that cannot be translated to humans without further research and clinical trials.