Polyphenols, or flavonoids, are likely a key component to what makes tea a healthful drink. These chemical compounds act as antioxidants, which control the damaging effects of free radicals in the body. Free radicals can alter DNA by stealing its electrons, and this mutated DNA can increase LDL cholesterol or alter cell membrane traffic—both harmful to our health. Though green tea is often believed to be richer in polyphenols than black or oolong (red) teas, studies show that—with the exception of decaffeinated tea—all plain teas have about the same levels of these chemicals, albeit in different proportions. Green tea is richest in epigallocatechin-3 gallate whereas black tea is richest in theaflavins; research has shown that both can exert health benefits. Herbal teas contain polyphenols as well but will vary highly depending on its plant origin.