Fresh blueberries have always been delicious. And for years we've known that they're good sources of vitamin C and fiber. Now we're learning that they're even better than that.

Scientists at Tufts University in Boston have found that blueberries are one of the world's most healthful foods.

Jim Joseph, Ron Prior, Barbara Shukitt-Hale and others conducted revealing research at the U.S. Department of Agriculture's Human Nutrition Research Center on Aging at Tufts.

We've known for some time that damage by oxygen "free radicals" causes many of the maladies that come with aging. "Antioxidants" are natural compounds that deactivate free radicals.

A Powerhouse of Antioxidants

And guess what? The humble blueberry is a powerhouse of antioxidants.

The story started many years ago when the Tufts scientists were screening fresh foods for their antioxidant activity. As they screened fruits and vegetables, they found blueberries to be extremely high in antioxidants.

The researchers then ran a study to find out if all blueberry species and varieties contain antioxidants. They found that all of the blueberries they tested contained high to very high levels of antioxidants.

Georgia Blueberry Bonanza

One of the varieties highest in antioxidants is the world-famous 'Tifblue,' developed by Tom Brightwell at Tifton, Ga., in 1955. Tifblue is planted on 40 percent of Georgia's 4,500 blueberry acres.

Georgia farmers are in the midst of their June-through-July harvest of these healthful berries.

The Tufts scientists have used Tifblue in a number of rat-feeding studies in the past few years. The blueberries were grown on farms in Clinch, Bacon and Appling counties and shipped frozen to Boston.

The scientists found that putting lab rats on blueberry-rich diets slowed age-related losses in their mental capacity, a finding with implications for humans.

Older rats fed the equivalent of half a cup of blueberries a day were not only more coordinated, but were smarter and had better memories than other rats in the same age range.

Georgia Blueberries in Japan

Many Georgia blueberries are now shipped to Japan. One of the main reasons is that the Japanese are interested in blueberry health benefits.

Of special interest to the Japanese is eye fatigue from lots of computer work. Researchers in Japan and other countries have found that blueberries reduce eye fatigue. The effect is probably due to compounds in the blueberries that strengthen the capillaries that feed eye muscles and nerves.

And there's more. Cranberries and blueberries are closely related. Both contain a compound that helps prevent urinary-tract infections by preventing bacteria from attaching to the urinary-tract lining.

The next time you go to the grocery store and see a container of fresh Georgia blueberries, buy them and eat them. Or at least take some home for your pet rat.