It’s the peak of the blueberry season in the south so that’s potentially good news for your brain. A new study from the University of Cincinnati found that adding blueberries to your diet may lower your chances of developing dementia.
UC scientist Robert Krikorian and his team of researchers studied the effects of berry consumption on Alzheimer’s disease and dementia for several years and recently published their findings in the journal Nutrients.
Blueberries contain high levels of micronutrients and antioxidants called anthocyanins. Anthocyanins help give blueberries their signature color and also protect the plant from infection and other threats. The same properties that protect the plant also benefit those who eat the fruit. Anthocyanins have been shown to reduce inflammation, improve metabolic function and enhance energy production at the cellular level.
Krikorian says about half the adult population develops some level of insulin resistance, known as prediabetes, by middle age. And that is a contributing factor to chronic diseases.
"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," Krikorian said. "Alzheimer's disease, like all chronic diseases of aging, develops over a period of many years beginning in midlife."
The study consisted of 33 subjects between the ages of 50-65 who were overweight, had prediabetes and were already noticing a mild memory decline associated with aging. That combination makes people more likely to experience dementia later in life.
Study participants were asked to abstain from berry consumption during the 12-week trial. Half of the group was given a blueberry powder they mixed with water which they consumed with their breakfast or dinner. It amounted to the equivalent of ½ cup of blueberries. The other half was given a placebo.
All study subjects were given a battery of tests to measure cognitive abilities that decline with aging and with late-life dementia. These tests included memory, mental flexibility and self-control.
Krikorian said the ones who consumed the freeze-dried blueberries showed improvement in the cognitive tasks that depend on executive control. "This was evident as reduced interference of extraneous information during learning and memory," Krikorian explained.
The blueberry eaters also had a lower fasting insulin level. That means they had improved metabolic function and had an easier time burning fat for energy. The blueberry group also had a higher degree of mitochondrial uncoupling, which is a cellular process associated with longevity and reduced oxidative stress. Krikorian said oxidative stress can lead to symptoms like fatigue and memory loss.
"This last finding was exploratory but points to an interesting, potential mechanism for blueberry benefits," he said.