New research from the University of Cincinnati shows that regular consumption of blueberries in middle age can help reduce the risk of Alzheimer's disease (dementia, also commonly known as "senile dementia").
A team led by Robert Krikorian, Ph.D., professor emeritus of the University of Cincinnati's Department of Behavioral Psychiatry and Neuroscience and chair of the Department of Psychology, has been studying the benefits of blueberry consumption in people at high risk for Alzheimer's and dementia for several years.
Previous research on berries that Krikorian has led has focused on older adults, but with this study, the team hopes to look at middle-aged adults to prevent and reduce the risk of dementia.
"We've seen cognitive benefits of blueberries in previous studies of older adults, and thought blueberries might be effective in insulin-intolerant young adults," Krikorian said."Alzheimer's, like all chronic diseases of aging, begins in midlife and then gets worse over the years." The
researchers recruited 33 Cincinnati-area patients between the ages of 50 and 65 who were in Pre-diabetic and overweight.They also experience a slight decline in memory as they age, and this group is at higher risk for late-onset dementia and other common diseases.
For 12 weeks, patients were instructed not to eat berries of any kind other than a daily sachet of the powdered supplement mixed with water and to eat it with breakfast or dinner.Half of the participants took powder containing about half a cup of blueberries, while the other half took a placebo.
The participants also took tests to measure cognitive decline that may occur in people with aging and late-onset dementia, such as executive functions such as working memory, mental flexibility and self-control.
Krikorian noted that the blueberry-eating treatment group showed improvements in cognitive tasks that rely on executive control."This suggests that there is less interference from foreign information during learning and memory," he said.
The findings, published in the journal Nutrients, also showed that the blueberry group had lower fasting insulin levels, which means the participants improved their metabolic function and were able to burn fat for energy more easily.
Blueberries are particularly high in micronutrients and antioxidants called anthocyanins, which contribute to blueberry coloring and also help protect blueberries from excessive radiation, infectious agents, and other threats.
These properties that help blueberries survive have also been shown to be beneficial in humans, such as reducing inflammation, improving metabolic function, and increasing energy production within cells.
The blueberry group also showed mild increases in mitochondrial uncoupling, a cellular process associated with increased lifespan and reduced oxidative stress, Krikorian said.Oxidative stress can lead to symptoms such as fatigue and memory loss.
"This latest finding is exploratory, but it does point to an interesting underlying mechanism by which blueberries are beneficial," he said.
