After 12 weeks of daily blueberry supplements researchers saw small cognitive improvements in trial participants. Depositphotos
Robert Krikorian has been studying the neurological effects of blueberries for several years. His prior work found several cognitive benefits for older subjects in adding blueberries to a diet but this new study set out to investigate whether the berries could be useful preventative agents when regularly consumed in middle-age.
“We had observed cognitive benefits with blueberries in prior studies with older adults and thought they might be effective in younger individuals with insulin resistance,” said Krikorian. “Alzheimer’s disease, like all chronic diseases of aging, develops over a period of many years beginning in midlife.”
To test the effects of blueberry supplementation in midlife, the researchers enrolled 33 adults between the ages of 50 and 65. All participants were at least overweight (with a body mass index of 25 or greater) and reported subjective cognitive complaints, suggesting the earliest stages of age-related cognitive decline.
The participants were blindly given a 12-week supply of either freeze-dried whole blueberry powder or a placebo powder. The blueberry powder was equivalent to around half a cup of blueberries a day. A number of cognitive tests were completed at the beginning and end of the trial, and several metabolic biomarkers were tracked.
According to Krikorian the most significant cognitive improvements seen after 12 weeks of blueberry supplementation were in tests relating to executive functions. The subjects consuming the blueberry powder also showed improvements to fasting insulin levels and increased mitochondrial uncoupling, a cellular process linked to healthy aging.
Of course, as with all studies like this one, there are plenty of caveats. The cohort was small and the duration of intervention was brief. So it’s difficult to immediately herald blueberries as a powerful dementia-prevention food.
Krikorian is aware of these limitations and calls for more studies to validate these findings. However, he also notes there is likely no harm in adding blueberries to a balanced diet as part of a broader healthy aging strategy.
“The sample size is an obvious limitation of the study, so it will be important to reproduce these findings, especially by other investigators,” said Krikorian. “In the meantime, it might be a good idea to consume blueberries on a regular basis.”
The new study was published in the journal Nutrients.
Source: University of Cincinnati