A large Harvard-led analysis suggests that regular consumption of blueberries may be associated with slower cognitive aging and better long-term brain health in older adults.

The findings come from the long-running Harvard University–associated Nurses’ Health Study, which tracked more than 16,000 participants over many years. Researchers observed that women with higher habitual intake of blueberries and strawberries experienced a noticeably slower decline in cognitive abilities compared to those who rarely consumed them.

The difference in cognitive performance was significant enough to be comparable to being about 2.5 years younger in terms of brain function, pointing to a potentially meaningful protective effect against age-related mental decline.

Scientists believe this benefit is largely driven by plant compounds found in berries, especially anthocyanins and other flavonoids. These antioxidants are able to cross the blood-brain barrier and are thought to reduce oxidative stress and inflammation, both of which are strongly linked to neuronal damage and cognitive deterioration over time.

They may also improve cerebral blood flow and support communication between neurons, particularly in brain regions involved in memory formation, such as the hippocampus.

Additional controlled clinical trials have supported these observations. In some studies, older adults who consumed roughly one cup of blueberries daily for several weeks showed measurable improvements in memory, attention, and processing speed compared to placebo groups.

Researchers caution that blueberries are not a treatment for cognitive decline or dementia. However, they note that regular inclusion of berries as part of a balanced diet may offer modest but meaningful long-term support for brain health.