Aug. 24, 2006 -- Diets rich in berries may help the brain stay sharp.
At least, that's what seems to happen in rats, researchers report in the online edition of Neurobiology of Aging. The scientists aren't making promises for people just yet. It's unknown if their findings apply to human brains.
Tufts University psychologist Barbara Shukitt-Hale, PhD, and colleagues conducted the latest berry test. They studied 60 young male rats, splitting the rats into three groups.
One group of rats got plain chow with no berries. A second group got the same chow laced with strawberry extract. The third group got chow laced with blueberry extract.
After two months on those diets, half the rats from each group were radiated to speed up the aging process. For comparison, the other rats weren't radiated.
Afterwards, the researchers trained all the rats to swim through an underwater maze to reach a hidden platform. The rats spent four straight days learning the maze.
Next, the researchers removed the platform and watched how the rats reacted. Then the scientists put the platform back in a new location and watched to see if the rats could find it.
Lastly, Shukitt-Hale and colleagues measured the rats' brain levels of dopamine, a brain chemical. Dopamine has many functions in the brain. A decrease in dopamine can cause a drop in memory, attention, and problem solving skills.
The radiated rats that had eaten the plain chow performed worst on the maze tests and had the lowest dopamine levels of any of the rats.
But the berry-eating, radiated rats didn't show those shortfalls. Their test results were generally comparable to those of rats that hadn't been radiated.
Shukitt-Hale's team doesn't tout any particular type of berry as having the best brain benefits. Berries vary in their nutrient mixes and may have different brain effects, but that's not certain yet, Shukitt-Hale and colleagues note.