It has long been known that antioxidants work to counteract the effects of aging and disease by fighting against free radicals. Free radicals are highly reactive molecules that contribute to various health problems ranging from cancer to the flu. Fresh vegetables and fruits are good sources of the antioxidants that neutralize free radicals, and it is now known that blueberries are the best source of all.

A study done at Tufts University in 1997 showed that, ounce for ounce, blueberries contain 3 times more antioxidants than spinach or an orange. The difference apparently comes from the color: blue pigments called anthocyanins are potent antioxidants. They are also found in strawberries and other blue and red fruits.

Preliminary studies involving blueberries have also been done by the U.S. Department of Agriculture. Rats given a diet supplemented with a few blueberries every day showed fewer signs of the mental and physical slowing that can come from aging. Diets that included strawberries and spinach were also effective.