Consuming Marmite -- a tangy British spread -- daily may be good for the brain, as it has been found to increase a chemical messenger associated with healthy brain function, a study has shown.

In the study, published in the Journal of Psychopharmacology, participants consuming a teaspoon of Marmite every day for a month, showed a substantial reduction of around 30 percent in their brain's response to visual stimuli. This beneficial effect may be due to the prevalence of vitamin B12 in Marmite increasing levels of a specific neurotransmitter -- known as GABA -- in the brain, the researchers said.

"The high concentration of Vitamin B12 in Marmite is likely to be the primary factor behind results showing a significant reduction in participants' responsiveness to visual stimuli," said Daniel Baker, Lecturer at the University of York in London. GABA inhibits the excitability of neurones in the brain, with the chemical acting to 'turn down the volume' of neural responses in order to regulate the delicate balance of activity needed to maintain a healthy brain.

The study suggested that dietary intervention could potentially have long-term effects on brain function. "These results suggest that dietary choices can affect the cortical processes of excitation and inhibition - consistent with increased levels of GABA - that are vital to maintaining a healthy brain," said Anika Smith, from the University of York.  Conversely, GABA imbalances are also associated with a variety of neurological disorders.

"Since we've found a connection between diet and specific brain processes involving GABA, this research paves the way for further studies looking into how diet could be used as a potential route to understanding this neurotransmitter," Baker said.