For Certain, Quercetin

Forget steak and chicken breasts, and put aside your protein powder.
We have a new muscle-building food to add to your menu: capers. Don’t like them? OK, then, how about onions? What these two unusual
vegetables (not to mention apples, tea, broccoli and citrus fruits) have
in common are high levels of a powerful antioxidant flavonoid called
quercetin. Scientists already knew that diets