Anthocyanins, the chemicals making blueberries blue, may also keep the brain healthy, according to research presented on June 4 at the Successful Aging conference, reports United Press International.

Other fruits and vegetables contain these chemicals, but blueberries contain the most, said Barbara Shukitt-Hale of the U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University in Boston. Blackberries and boysenberries also have high levels.

Shukitt-Hale, and her colleague James Joseph, found that old rats whose nutritionally well balanced diet was supplemented with the human equivalent of half cup of blueberries a day for two months, were able to reverse age-related declines in the ability to do a motor task, hanging on to a rotating bar, and a mental task such as learning how to find a perch in small pool of water.

Shukitt-Hale said hydroxycinnamates, another class of chemicals in the berries, are also important, and that it is very likely both classes of chemicals work together.

Tests on human cells in test tubes found that the two classes of chemicals protected against the damage caused by free radicals. Many scientists regard this so-called oxidative damage as a cause of aging and age-linked damage to the body.

David Morgan, a pharmacologist at the University of South Florida, found that mice genetically altered to have symptoms and brain changes similar to those in Alzheimer's disease, when fed blueberries, showed improvement on some learning tasks as compared with mice not given the diet. Moreover, said Shukitt-Hale, an analysis of the brain tissue of these mice showed the structures in the brain involved in learning and memory were better able to communicate with one another.

Shukitt-Hale said it was too early to say for sure if blueberries can delay or prevent Alzheimer's disease, "but you cannot get hurt by trying. And they taste good, too."

Morgan is more cautious. He said the blueberry diet did not improve the performance of the Alzheimer-like mice on other mental tests. The real problem in Alzheimer's disease, he said is abnormal protein deposits in the brain. He said to really begin to get a good understanding of what blueberries in the diet can do, it is necessary to "start mice on this diet at a very young age and take them out as far as we can take them."

Source: United Press International