Eating blueberries on a regular basis may reduce the risk of dementia

Researchers have found that adding blueberries to the diet of certain middle-aged people may reduce the risk of Alzheimer's disease, according to a paper recently published in the journal of Nutrients. Blueberries contain micronutrients and the antioxidant anthocyanins. Study leader Robert Krikorian, PhD, of the University of Cincinnati, said anthocyanins help protect plants from excessive radiation and infectious agents, and that properties that help blueberries survive better also have benefits for humans, such as reduced inflammation, improved metabolic function and increased energyproduction within cells.

In the United States, about 50 percent of people develop insulin resistance around middle age, which often leads to a condition known as "pre-diabetes." Researchers recruited 33 pre-diabetic patients between the ages of 50 and 65 from around the Cincinnati area. These patients were overweight and had a mild decline in memory with age. For 12 weeks, participants were instructed to abstain from any type of berry fruit, in addition to eating a pack of supplemental powder that could be mixed with water for breakfast or dinner every day. Half of the participants received a powder equivalent to half a cup of whole blueberries, while the other half received a placebo. The researchers also tested the participants' levels of decline in certain cognitive abilities, such as executive functions such as working memory, mental flexibility and self-control.

 The results found that those in the blueberry treatment group showed improvements in cognitive tasks that relied on executive control, which significantly reduced interference from foreign information during learning and memory. In addition, the blueberry group also had lower fasting insulin levels, meaning participants had improved metabolic function and were able to burn fat for energy more easily. The blueberry group showed slightly higher levels of mitochondrial uncoupling, a cellular process associated with longer life spans and reduced oxidative stress. Oxidative stress can cause symptoms such as fatigue and memory loss. The main conclusion of the study, Dr. Krikorian said, is that regular blueberry supplementation in the diets of middle-aged people at risk for Alzheimer's may reduce their chances of developing the disease.