We have known for a while that frequently eating berries has health benefits. A recent study found that overweight middle-aged persons eating blueberries daily for 12 weeks resulted in both metabolic and memory improvements.
The researchers stated that the results suggest that frequently eating blueberries could be protective against cognitive decline and lower the risk of dementia later on in life.
The study involved thirty-three overweight prediabetic middle-aged adults who already felt that their memory was not as good as in years past. They were randomly assigned to either the blueberry (whole freeze-dried blueberry powder) group or the placebo group (a similar looking powder that did not contain blueberries). The blueberry powder was equivalent to 1/2 cup whole blueberries and was eaten once a day for 12 weeks. The benefits of blueberries are thought to be from micronutrients and anthocyanins, which are antioxidants.
By the way, all berries (raspberries, blackberries, strawberries, etc.) are slightly different in micronutrients and are viewed as beneficial to health and lowering the risk of chronic diseases, including the risk of dementia. As are colorful fruits and vegetables. Don't focus on just one type of berry - eat them all!
From Medical Xpress: Regular blueberry consumption may reduce risk of dementia, study finds
Researchers led by UC's Robert Krikorian, Ph.D., found that adding blueberries to the daily diets of certain middle-aged populations may lower the chances of developing late-life dementia.
While not entirely different from other berries and plants like red cabbage, Krikorian said blueberries have a particularly high level of micronutrients and antioxidants called anthocyanins. Anthocyanins help give blueberries their namesake color and also help defend the plants against excess radiation exposure, infectious agents and other threats, Krikorian said.
These same properties that help blueberries survive also provide benefits to humans, Krikorian said, such as reducing inflammation, improving metabolic function and enhancing energy production within cells.
Previous berry studies Krikorian led focused on older populations, but with this research, the team wanted to study middle-aged individuals in order to focus on dementia prevention and risk reduction.
Krikorian explained that about 50% of individuals in the U.S. develop insulin resistance, commonly referred to as prediabetes, around middle age. Prediabetes has been shown to be a factor in chronic diseases, he said.
"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, professor emeritus and director of the division of psychology in the UC College of Medicine's Department of Psychiatry and Behavioral Neuroscience. "Alzheimer's disease, like all chronic diseases of aging, develops over a period of many years beginning in midlife."
The researchers enrolled 33 patients from around the Cincinnati area between the ages of 50-65 who were overweight, prediabetic and had noticed mild memory decline with aging. Krikorian said this population has an increased risk for late-life dementia and other common conditions.
Over a period of 12 weeks, the patients were asked to abstain from berry fruit consumption of any kind except for a daily packet of supplement powder to be mixed with water and consumed either with breakfast or dinner. Half of the participants received powders that contained the equivalent of one-half cup of whole blueberries, while the other half received a placebo.
Participants were also given tests that measured certain cognitive abilities that decline in patients with aging and late-life dementia, such as executive functions like working memory, mental flexibility and self control.
Krikorian said those in the blueberry-treated group showed improvement on cognitive tasks that depend on executive control....Patients in the blueberry group also had lower fasting insulin levels, meaning the participants had improved metabolic function and were able to more easily burn fat for energy.
Krikorian said the blueberry group displayed an additional mild degree of higher mitochondrial uncoupling, a cellular process that has been associated with greater longevity and reduced oxidative stress. Oxidative stress can lead to symptoms like fatigue and memory loss.