Love it or hate it, Marmite has been found to have a significant effect on the activity in the brain.
Research by the University of York has found that the high level of vitamin B12 in found in the divisive savoury spread increases levels of a specific neurotransmitter – known as GABA –associated with healthy brain function.
GABA inhibits the excitability of neurons, cutting down the volume of responses in order to regulate a delicate balance of brain activity. Imbalances in GABA have been linked with neurological disorders including epilepsy, autism and depression.
These findings are significant because they suggest alternations in diet could potentially be used to increase GABA concentrations, and, in turn, reduce symptoms such as seizures.
In the study, a group of 20 adult participants, 10 of which were male with a mean age of 22, were asked to look at patterns on a screen while they had had their brain activity measured using electroencephalography (EEG), via scalp sensors. It was previously determined none of the group were smokers, recreational drug users, or had any allergies.
Large stripy patterns flickered on and off the screen, at a set frequency (7Hz, or 7 times per second), causing neurons in the visual parts of the brain to respond at the same frequency.
The volunteers were then randomly divided into two groups, with one asked to eat a teaspoon of Marmite every day for a month, while the control group ate a daily teaspoon of smooth peanut butter instead. Beyond this, both groups stuck to their usual diets.
At the end of the month, the participants were re-tested using the same flickering stripes and EEG readings, with the results showing a substantial reduction of around 30 per cent in the brain response of those who ate Marmite.
"These results suggest dietary choices can affect the cortical processes of excitation and inhibition – consistent with increased levels of GABA – that are vital in maintaining a healthy brain," said Anika Smith, PhD student in York's Department of Psychology and first author of the study.
"As the effects of Marmite consumption took around eight weeks to wear off after participants stopped the study, this suggests dietary changes could potentially have long-term effects on brain function."
Marmite has around 16 times more vitamin B12 than peanut butter, as well as three times more vitamin B6 and 1.85 times more glutamate.
“All three substances are implicated in GABA production, but we can't say which is the most important (though we suspect it is B12). Our next study plans to investigate this in more detail,” Dr Daniel Baker, lecturer in the department of psychology and senior author of the paper, told WIRED.
"Although GABA is involved in various diseases, we can make no therapeutic recommendations based on these results and individuals with a medical condition should always seek treatment from their GP,” he added.
Dr Laura Phipps from Alzheimer’s Research UK said the idea particular foods may influence brain activity was "interesting" but added she was unclear if or how this could translate into long-term benefits against particular brain diseases. She said the study also fails to tell us whether Marmite could be beneficial for our memory – a lack of B12 has previously been linked to memory deficiencies – or affect the onset of dementia.
“While a healthy, balanced diet has been linked to a healthy brain as we age, no one particular food or supplement has been shown to be most effective at reducing dementia risk,” she continued.
Published in the Journal of Psychopharmacology, the research was supported by the Wellcome Trust, the Centre for Chronic Diseases and Disorders at the University of York and the Leverhulme Trust.
The findings could lead to breakthroughs in future, helping scientists understand more about neurological conditions that are linked to GABA, however given the limited study and questions raised by the outcome, the scientists stress further research is required.
This article was originally published by WIRED UK
