Scientists from the University of Cincinnati have found that regularly eating blueberries in midlife may help reduce the risk of developing dementia later in life.
The study, led by Robert Krikorian and published in the journal Nutrients, adds to growing evidence that certain nutrient-rich foods can play an important role in protecting brain health as we age.
Blueberries are small, dark-blue or purple berries that grow on perennial flowering plants and are widely enjoyed around the world.
They are rich in dietary fibre, which supports healthy digestion, and are also an excellent source of vitamins such as vitamin C and vitamin K. One cup of blueberries provides about 24 percent of the recommended daily intake of vitamin C.
In addition to these nutrients, blueberries are particularly high in anthocyanins and proanthocyanidins, two powerful plant compounds known as flavonoids that give many fruits and vegetables their deep colours.
These flavonoids are thought to play a key role in disease prevention. They have been linked to a reduced risk of cardiovascular disease, high blood pressure, hyperlipidaemia, diabetes and certain types of cancer.
Because of their antioxidant and anti-inflammatory properties, they are also widely studied for their potential to protect brain cells and support cognitive function.
Dementia in later life usually develops gradually over many years, often beginning with subtle changes in brain function during midlife.
At the same time, metabolic problems tend to increase in middle age and are recognised as major risk factors for cognitive decline and dementia.
Previous research has already suggested that blueberry consumption can improve memory, influence metabolism and support brain function, making it a promising candidate for early intervention.
In this study, researchers examined the effects of daily blueberry intake in middle-aged adults who were at higher risk of developing dementia.
The participants were overweight men and women between 50 and 65 years of age who also had insulin resistance, a metabolic condition that increases the risk of both type 2 diabetes and cognitive decline.
Cognitive and metabolic functions were carefully measured before and after the blueberry intervention.
The results showed that participants in the blueberry group performed better on several cognitive tasks and reported fewer difficulties with memory encoding in their everyday activities.
In addition, this group showed a reduction in hyperinsulinaemia, a condition in which excessive amounts of insulin are circulating in the blood relative to glucose levels.
Hyperinsulinaemia can contribute to metabolic dysfunction and is closely linked to an increased risk of dementia.
Together, these findings suggest improvements in executive function and metabolic health among those who consumed blueberries regularly.
The researchers also noted that the observed metabolic changes may be directly related to the anthocyanins and proanthocyanidins found in blueberries, which are known to influence both brain and metabolic pathways.
These findings support the idea that regular blueberry consumption during midlife may help protect against cognitive decline in individuals who are at higher risk of developing dementia.
However, the research team emphasised that further studies are needed to assess the long-term effects of blueberry consumption over extended periods and to examine whether similar benefits are seen in people who are not overweight but still have elevated dementia risk.
Overall, the study highlights the potential of simple dietary choices, such as including blueberries in the daily diet, to support brain health and possibly reduce the risk of dementia later in life.
