Blueberries have benefits — but there’s no proof they stave off Alzheimer’s

Regularly eating blueberries may help stave off Alzheimer’s disease, researchers at the University of Cincinnati have claimed.

Their research involved 47 adults over the age of 68, all of whom had mild cognitive impairments, a risk factor for Alzheimer’s. Every day for 16 weeks they gave one group a cup of freeze-dried blueberry powder, and the other group a placebo.

The study’s lead author, Dr Robert Krikorian, said: ‘There was improvement in cognitive performance and brain function in those who had the blueberry powder compared with those who took the placebo. The blueberry group demonstrated improved memory and improved access to words and concepts.’

MRI scans showed an increase in brain activity among the subjects who consumed the blueberry powder, the researchers said.

Dr Krikorian said he believed the effects were caused by anthocyanins. These are flavonoids — molecules found in a variety of fruit and vegetables — which previous studies have shown to improve brain function in animals.

A further study involved twice as many subjects — this time, while the subjects had reported memory loss, they had no measurable cognitive decline when they entered the study. The researchers said the results were ‘not as robust’.

Dr Krikorian said his work suggests blueberries may be effective in treating patients with existing cognitive impairments, but not those who are yet to display possible symptoms of Alzheimer’s.

The results of the two studies were presented at a meeting of the American Chemical Society in San Diego, California.

Instant analysis
The numbers in the study are dubious. Fifty study subjects does not an association make. With Alzheimer’s, people wax and wane in terms of their cognitive ability — sometimes they will perform better than others. It is difficult to say the differences noted in the MRI scans are down to blueberries.
Research score: N/A (full paper not seen)