Blueberries Pack a Powerful Antioxidant Punch

Blueberries have slightly more calories and less vitamin C than other berries, but few foods have caused as much scientific optimism and excitement.

After measuring more than 40 commercially available fruits and vegetables for antioxidant activity, the U.S. Department of Agriculture has ranked blueberries as far and away the best. According to the director of those studies, it would take five servings of fruits and vegetables such as peas, carrots, apples, squash and broccoli, to equal the antioxidant power of half a cup of blueberries.

The role of antioxidants and other phytochemicals (plant chemicals) is the subject of a great deal of ongoing research. Antioxidants are thought to neutralize free radicals, which are unstable oxygen molecules associated with cancer, heart disease and the effects of aging. There are literally thousands of these phytochemicals occurring naturally in all plant products. (Anthocyanins, for example, are highly concentrated in the blue pigment of blueberries.)

The range of things they may do is pretty impressive, especially when consumed the way they grow. In other words, isolating the individual phytochemicals (as in dietary supplements) is not likely to produce the same effect as eating a wide range of fruits and vegetables every day.

Blueberries, in particular, are credited with working like cranberries to help ward off urinary tract infections, and a couple of years ago, they were shown to reverse mental declines in old laboratory rats. Since we probably don’t need to produce too many smarter old rats, the hope is that blueberries will have the same effect in humans. Other researchers are looking into the connection between blueberries and prevention of macular degeneration (something already credited to their European cousins, the bilberries).

There are two kinds of blueberries: cultivated and wild. Cultivated berries are about three to four times as large as the wild ones and have a powdery protective coating. Wild blueberries are smaller and darker and have a more intense flavor.

Both types freeze extremely well and retain their nutritional value when frozen.

Commercially frozen berries often have sweetener added to them, so their calorie count is higher. If you want to eliminate that problem, they’re very easy to freeze at home. Just take unwashed blueberries and spread them out on a cookie sheet or plate in the freezer. Once they’ve frozen, place them in a heavy plastic bag. This will ensure that you have blueberries all year.

When you buy fresh blueberries, check to make sure none are moldy or have started to deteriorate. If you find a couple of bad ones, throw them out before they can infect the rest.

Of course everybody knows that blueberries can be added to pancake, waffle or muffin batter, but they also can be stirred into nonfat yogurt, added to hot and cold cereals, or to a fresh summer salad.

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Dr. Sheldon Margen is a professor of public health at UC Berkeley; Dale A. Ogar is managing editor of the UC Berkeley Wellness Letter. Send questions to Dale Ogar, School of Public Health, UC Berkeley, Berkeley, CA 94720-7360, or e-mail to daogar@uclink4.berkeley.edu. Eating Smart appears the second and fourth Mondays of the month.