Berry good way to keep brain young
Scientists have found the first evidence that health- improving compounds found in the fruits activate the brain's natural "housekeeping" mechanism.
This mops up and recycles toxic proteins linked to the memory loss and mental decline many people experience as they get older, according to the study.
Experts yesterday said the study highlighted the importance of fruits such as berries in the diet to help improve well-being, due to their high content of polyphenols - healthy chemicals found in plants.
US researchers focused on special immune system cells in the brain called microglia, which engulf, remove and recycle harmful biochemical debris.
Lead scientist Dr Shibu Poulose, from the Human Nutrition Research Centre on Aging in Boston, Massachusetts, said: "In ageing, microglia fail to do their work, and debris builds up. In addition, the microglia become over-activated and actually begin to damage healthy cells in the brain.
"Our research suggests that the polyphenolics in berries have a rescuing effect. They seem to restore the normal housekeeping function.
"These findings are the first to show these effects of berries."
The researchers, whose findings were presented at the National Meeting of the American Chemical Society in Boston, used mouse brain cells in their study.
They found that extracts of blueberries, strawberries and acai berries - a grape-like fruit from the Brazilian rainforest - blocked the action of a protein that stops microglia doing their job. Other fruits and vegetables contain the same beneficial polyphenol chemicals, said the scientists - especially those with deep red, orange or blue colours.
The pigments are due to a polyphenol family called anthocyanins which are powerful antioxidants, helping protect the body from harmful material.
Dr Poulose stressed the importance of eating the whole fruit to obtain the full benefit of hundreds of chemicals. Frozen berries available all the year round are excellent sources of polyphenols, said the scientists.
Previous work by the same team showed that age-related decline could be reversed in laboratory rats fed strawberry, blueberry and blackberry extracts.
Carina Norris, a Fife-based nutritionist, said: "All the evidence stacking up shows that eating a nice variety of brightly-coloured berries can only be good for us. While we are not saying there is any one 'super food' or 'super berry' that is going to stop your brain ageing, it is more evidence to encourage people to eat more of these fresh, healthy foods."