Green tea may be a 'brain booster'

“Looking for a morning brain boost? Forget coffee – green tea holds the key for men”, suggests the Daily Mail.

Earlier this month we were told that green tea helps prevent bowel cancer, now new research suggests it could aid memory and cognition (thinking ability).

This headline stems from a small study involving brain scans on 12 healthy males. The researchers were using a type of scan known as functional magnetic resonance imaging (fMRI), which provides a real-time continuous scan of blood flow inside the brain. The idea underpinning fMRI is that increases in blood flow in certain areas of the brain correspond to neural activity.

The researchers found that drinking a soft drink laced with green tea extract appeared to increase blood flow to a part of the brain called the dorsolateral prefrontal cortex (DLPFC). The DLPFC is thought to be involved in cognitive tasks such as long-term memory, reasoning, and comprehension.

However, it also showed that this did not affect performance in a working memory task that volunteers performed each time their brains were scanned.

The headline “forget coffee – green tea holds the key for men”, is an eye-catching, but misleading, extrapolation of the results of this study. However, reporting that soft drinks containing green tea may cause small changes in blood flow in the brain (as was actually measured in the study), but do not seem to help in performing memory tasks, was perhaps seen as less headline-worthy.