Berries are a colorful and nutritious food containing many types of bioactive compounds, including anthocyanins, a type of polyphenol with blue/purple pigment. Anthocyanins from berries such as blueberries, black raspberries, chokeberries, and bilberries are recognized for their ability to protect against cardiovascular and neurodegenerative diseases. Findings of a recent systematic review provide robust evidence demonstrating the beneficial effects of anthocyanins on cognitive performance and cardiovascular disease risk factors.
Cognitive performance refers to a set of mental skills such as attention, memory, psychomotor speed, and executive function that develop through early adulthood and then decline in old age. As the world population ages, cognitive impairment is a growing public health concern that requires targeted strategies for prevention. Impaired vascular function, a factor that contributes to poor brain health and cognitive performance with age, may be modifiable with diet and lifestyle changes. Previous research has demonstrated that eating blueberries improves vascular function (measured with flow mediated dilation) in healthy men; but further research is needed to understand the molecular mechanisms.
Polyphenols are a large class of bioactive compounds found in fruits, vegetables, teas, coffee, wine, and olive oil with antioxidant properties because of their many phenol rings. Due to their special cyclized electron structure, phenols capture and neutralize oxygen radicals and reflect light at unique wavelengths, giving them vibrant color. A previous systematic review of research on blueberries found good evidence to support their ability to improve memory, executive function, and psychomotor function in adults with mild cognitive impairment; however, less research has focused on total anthocyanins in the diet.
The authors searched for studies investigating the six most anthocyanin-rich fruits (i.e., blackcurrant, black raspberry, blueberry, bilberry, chokeberry, and elderberry). They selected all randomized, placebo-controlled intervention studies in humans that investigated at least one cardiometabolic or cognitive performance parameter for inclusion in their analysis. Although methods of data collection used among the studies widely varied, the authors extracted data from their selected studies and combined it into clusters for comparison.
The authors of the review investigated the effects of berry anthocyanin supplementation on memory in 14 studies with mostly older adult participants, revealing improved memory, especially verbal memory, and symptoms of mild cognitive impairment. In young and middle-aged adults, multiple studies found improvements in attention and psychomotor speed with anthocyanin supplementation. The research revealed that short-term berry supplementation was sufficient to produce benefits on attention and psychomotor speed, but long-term supplementation was best for memory.
All studies that measured flow mediated dilation, the most accurate measure of vascular function, found an improvement following anthocyanin supplementation except for one study in smokers. Long-term berry supplementation also lowered blood pressure in adults at high risk for cardiometabolic disease, but not healthy adults, indicating that individual characteristics alter a person’s response to anthocyanin supplementation.
This large systematic review provides robust evidence for the beneficial effects of berry anthocyanins on multiple markers of cognitive and cardiovascular performance.