Blueberries can cut dementia risk

Regular consumption of blueberries in middle age may reduce the risk of dementia in later life, according to a new study from the University of Cincinnati.

A team led by Dr Robert Krikorian has been researching the benefits of blueberries for people at increased risk of Alzheimer’s and dementia for several years.

Previous studies of the berries that Krikorian led focused on elderly populations, but with this research, the team wanted to look at middle-aged individuals to focus on dementia prevention and risk reduction.

“We had seen cognitive benefits with blueberries in previous 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 Department of Behavioural Psychiatry and Neuroscience. from the UC School of Medicine.

“Alzheimer’s disease, like all chronic diseases of aging, develops over a period of many years beginning in middle age.”

The researchers recruited 33 Cincinnati-area patients between the ages of 50 and 65 who were overweight, prediabetic and had noted mild memory decline with aging, a population group that has a higher risk of suffer from tardive dementia and other common conditions.

Over a 12-week period, patients were asked to refrain from eating berries of any kind, except for one daily packet of powdered supplement that they mixed with water and consumed with breakfast or dinner. Half of the participants received powders containing the equivalent of half a cup of whole blueberries, while the other half received a placebo.

The participants also took tests that measured certain cognitive abilities that decline in patients with aging and late-onset dementia, such as executive functions like working memory, mental flexibility and self-control.

Krikorian noted that those in the blueberry-treated group showed improvement in cognitive tasks that rely on executive control. “This showed up as less interference from extraneous information during learning and memory,” he said.

The results, published in journal Nutrients, also showed that patients in the blueberry group had lower fasting insulin levels, meaning participants improved their metabolic function and were able to more easily burn fat for energy.

Blueberries are particularly high in micronutrients and antioxidants called anthocyanins, which help give them their colour and also help defend the plants against excess exposure to radiation, infectious agents and other threats.

These same properties that help blueberries survive have also been shown to bring benefits to humans, such as reducing inflammation, improving metabolic function and increasing energy production in cells.

According to Krikorian, the blueberry group also showed an additional mild degree of increased mitochondrial uncoupling, a cellular process that has been associated with increased longevity and reduced oxidative stress. Oxidative stress can cause symptoms such as fatigue and memory loss.

“This latest finding was exploratory, but it does point to an interesting potential mechanism for blueberry benefits,” he said.