Yeast extract spread linked to healthy brain
5th April 2017 – It's the pot of brown yeast extract that you either love or hate, but scientists say Marmite could be good for your brain.
A team from the University of York say they have found a possible link between eating Marmite and an increase in levels of gamma-aminobutyric acid (GABA) – a neurotransmitter associated with healthy brain function.
They say high levels of vitamin B12 in the food paste may be responsible.
A teaspoon of yeast extract
The study, in the Journal of Psychopharmacology, involved 28 adults with an average age of 22. Half the group ate a teaspoon (5g) of Marmite every day for a month and the remainder were given peanut butter instead.
All the participants were exposed to flickering lights and their brains' electrical activity responses measured by electroencephalography (EEG).
Those who ate the Marmite displayed an average reduction of around 30% in their brain's response to the visual stimuli compared with those in the control group who ate peanut butter.
GABA inhibits the excitability of neurons in the brain. The chemical effectively 'turns down the volume' of neural responses in order to regulate the delicate balance of activity needed to maintain a healthy brain. GABA imbalances are associated with a number of neurological disorders, including epilepsy.
The research has attracted comments from a number of experts.
David Smith, professor emeritus of pharmacology at the University of Oxford, disputes whether vitamin B12 could be the active factor. "The authors might consider whether folic acid, present in Marmite at levels about 150 times greater than B12 could be the active factor," he says.
Self-confessed Marmite hater Catherine Collins, a registered dietitian who reviews dietary articles for the BootsWebMD website, says: "That Marmite had an influence was not in doubt. However, as a dietitian I'd suggest that it was the addition of over half a gram of salt, around a tenth of the daily recommended amount, that may have had a greater effect through its impact on thirst and hydration, and possibly blood pressure."
Could Marmite have a role in dementia prevention?
Dementia experts have also commented on whether the findings could be relevant for the condition. Dr Laura Phipps from Alzheimer's Research UK, says: "Marmite contains high levels of vitamin B12, and while deficiency in this vitamin can cause memory problems, this study does not tell us whether Marmite could be beneficial for our memory or affect the onset of dementia.
"The interesting outcome of this study of young people is the suggestion that particular foods may influence brain activity but we don't know if or how this could translate into long-term benefits against particular brain diseases."
Dr James Pickett, head of research at the Alzheimer's Society, comments: "Evidence shows that our diet plays an important role in the way our brain functions. This research only looked at how men in their 20s responded to visual stimuli rather than testing their thinking or memory, so there's no way to say from this study whether eating Marmite can affect your dementia risk. But the study does give us a deeper understanding of how certain aspects of diet could affect the function of nerve cells in the brain."