Metabolic function and cognitive performance begin to decline as early as the middle-age years – between the ages of 45 and 65 years. Dietary modification might be a useful strategy for improving or even reversing these declines. A recent study demonstrates that consumption of a wild blueberry extract improves metabolic function and cognitive performance in middle-aged adults.

Blueberries are rich sources of anthocyanins, a type of flavonoid compound that exerts antioxidant and anti-inflammatory effects. Epidemiological evidence suggests that regular consumption of blueberries reduces a person’s risk of developing cardiovascular disease, cancer, and type 2 diabetes.

The randomized controlled cross-over trial involved 35 people between the ages of 40 and 65 years. After eating a breakfast meal consisting of buttermilk biscuits with unsalted butter and apple jelly, scrambled eggs, and honeydew melon balls, the participants drank a beverage containing 25 grams of freeze-dried blueberries (roughly equivalent to 1 cup of fresh berries) and some flavoring agents. On a separate occasion, participants ate the same breakfast meal and drank a placebo beverage that contained the flavoring agents (and similar caloric content) only. Each of the participants performed cognitive tasks and provided blood samples before and after each meal/treatment. The authors of the study assessed the participants for changes in their episodic memory and executive function as well as plasma levels of glucose, insulin, and triglycerides.

The authors found that the participants who drank the blueberry beverage performed better on the cognitive tests than those who drank the placebo. They also noted that the blueberry beverage drinkers had lower insulin and glucose levels than those who drank the placebo.

These findings suggest that blueberry consumption improves metabolic markers and cognitive performance in middle-aged adults and underscore the importance of regular consumption of flavonoid-rich fruits and vegetables.

• Link to study abstract.