NN: Blackcurrant juice boosts blood flow to the brain

An international team of scientists has found that drinking blackcurrant juice increases blood flow to the frontal lobes of the brain—both at rest and during mental activity. The study was published in the journal Nutritional Neuroscience (NN).

The experiment involved 20 healthy young adults aged 18 to 35. During one laboratory visit, participants drank juice made from the “Blackadder” variety of blackcurrant, enriched with 500 milligrams of polyphenols; during another, they received a placebo identical in taste and color but without active compounds. The researchers then used near-infrared spectroscopy to monitor changes in blood oxygen levels, which reflect cerebral blood flow activity.

The results showed that just 35 minutes after consuming the juice, the level of oxyhemoglobin—a measure of blood oxygen saturation—significantly increased in the left frontal lobe, while deoxyhemoglobin levels decreased. This indicates more efficient oxygen delivery to the brain and improved vascular function. The overall blood volume in this region also rose slightly.

“We observed a clear increase in blood flow in the left prefrontal cortex, which is responsible for attention and decision-making. This aligns with the fact that the left side of the brain is more actively involved in working memory processes,” explained the study’s lead author, Dr. Anthony Watson, head of the Human Nutrition and Physical Activity Research Center at Newcastle University.

Blackcurrants are rich in polyphenols—particularly anthocyanins, plant compounds known for their beneficial effects on blood vessels and heart health. The researchers suggest that these compounds may enhance nitric oxide production, which dilates blood vessels, or influence dopamine and serotonin levels, which also play roles in regulating cerebral blood flow.