Blueberries may be more effective in treating patients with cognitive impairments, but may not show measurable benefit for those with minor memory issues or who have not yet developed cognitive problems, according to new research presented at the 251st National Meeting & Exposition of the American Chemical Society (ACS).
The antioxidant-rich blueberry, already labeled a superfruit for its power to potentially lower the risk of heart disease and cancer, also could be another weapon in the war against Alzheimer's disease.
“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, Ph.D., leader of the research team. He noted blueberries’ beneficial effects could be due to flavonoids called anthocyanins, which have been shown to improve animals’ cognition.
Currently 5.3 million people suffer from Alzheimer’s disease. By 2025, that number could rise 40 percent to more than 7 million, and could almost triple by 2050, according to the Alzheimer’s Association.
Researchers at the University of Cincinnati Academic Health Center conducted two human studies to follow up on earlier clinical trials. One study involved 47 adults aged 68 years and older who had mild cognitive impairment, a risk condition for Alzheimer’s disease. The researchers gave them either freeze-dried blueberry powder, which is equivalent to 1 cup of berries, or a placebo powder once a day for 16 weeks. Data revealed 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. The team 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 years who were divided into four groups. Participants didn't 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," Krikorian said. “Cognition was somewhat better for those with powder or fish oil separately, but there was little improvement with memory." He said fMRI results were not as striking for those receiving blueberry powder, and the effect may have been smaller in this case because the participants had less severe issues when they entered the study.