Researchers from the University of York have found that Marmite can alter the fine balance of electrical activity in the brain, suggesting that these changes are due to the high levels of vitamin B12 found in the spread. The study is published today in the Journal of Psychopharmacology.
The researchers were interested in the delicate balance between excitation and inhibition in the brain, which is controlled by levels of chemicals called neurotransmitters. They were particularly interested in how boosting the production of a neurotransmitter called GABA could alter this balance. GABA is a chemical that dampens the activity of nerve cells in the brain. Vitamin B12 is involved with the production of GABA, and is naturally found in animal products, such as meat and dairy, but is also fortified in other foods such as cereals and spreads, including Marmite.
The researchers recruited 28 volunteers into the study, made up of 10 men and 18 women, with an average age of 22. At the start of the study, the volunteers underwent electroencephalography (EEG), which involved the placement of 64 recording electrodes across their scalp to measure brain activity. The volunteers were shown flickering pictures with different contrast levels, and by altering the order the pictures were shown, the researchers were able to gain insight into the balance of brain activity. The volunteers were then randomly assigned to one of two groups, one receiving Marmite, and the other receiving peanut butter. They were instructed to eat one teaspoon of their spread every day for a month.
Following this month either eating Marmite or peanut butter, the volunteers then underwent another EEG. This showed that those who ate Marmite had a 30% dialling down of excitatory brain activity in response to the visual task, compared with those who had peanut butter. The researchers suggest this may be due to an increase in levels of GABA in the brain.
To see how long this effect lasted, five of the volunteers who ate Marmite underwent another EEG two months after stopping eating the spread, which showed that the effect had worn off. The researchers suggested that dietary consumption of vitamin B12, such as by eating Marmite, could be used to help people with conditions in which excessive excitatory brain activity is involved, such as epilepsy.
Dr Laura Phipps of Alzheimer’s Research UK, said:
“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.
“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. As well as a balanced diet, there are lifestyle changes we can all make to reduce our risk of developing dementia. Keeping physically and mentally active, eating a healthy balanced diet, not smoking, drinking in moderation, keeping cholesterol and blood pressure under control and your weight in check are all ways to support healthy brain ageing.”