Eating blueberries, the well-known 'super fruit', may not only lower the risk of heart disease and cancer, but also provide protection against Alzheimer's disease, a new study has claimed.
The fruit is loaded with healthful antioxidants, and these substances could help prevent the devastating effects of this increasingly common form of dementia, researchers said.
"Our new findings corroborate those of previous animal studies and preliminary human studies, adding further support to the notion that blueberries can have a real benefit in improving memory and cognitive function in some older adults," said Robert Krikorian from University of Cincinnati in the US.
Blueberries' beneficial effects could be due to flavonoids called anthocyanins, which have been shown to improve animals' cognition, he said.
Researchers conducted two human studies to follow up on earlier clinical trials. One study involved 47 adults aged 68 and older, who had mild cognitive impairment, a risk condition for Alzheimer's disease.
Scientists gave them either freeze-dried blueberry powder, which is equivalent to a cup of berries, or a placebo powder once a day for 16 weeks.
"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," said Krikorian.
Researchers also conducted functional magnetic resonance imaging (fMRI), which showed increased brain activity in those who ingested the blueberry powder.
The second study included 94 people aged 62 to 80, who were divided into four groups. The participants did not have objectively measured cognitive issues, but they subjectively felt their memories were declining.
The groups received blueberry powder, fish oil, fish oil and powder or placebo.
"The results were not as robust as with the first study. Cognition was somewhat better for those with powder or fish oil separately, but there was little improvement with memory," said Krikorian.
Also, fMRI results were not as striking for those receiving blueberry powder. The effect may have been smaller in this case because these participants had less severe issues when they entered the study, researchers said.
