Yeast extract may boost brain function


Marmite is far from one of the most popular foods in the United States. In fact, many Americans are unlikely to have heard of it. A new study, however, suggests that when it comes to boosting brain function, Marmite triumphs over peanut butter.

Marmite is a British brand of food paste made from yeast extract – a food additive created from brewer’s yeast.

While Marmite is one of the most popular sandwich spreads in the United Kingdom, not everyone is a fan. Its powerful, distinctive flavour is so divisive that even its manufacturers, Unilever, launched a “Love It or Hate It” campaign in the mid-1990s, a slogan that has followed the brand ever since.

A new study, however, suggests that when it comes to boosting brain function, Marmite triumphs over peanut butter.

A new study, however, could turn Marmite hatred on its head, after finding that the yeast extract may increase levels of a neurotransmitter associated with healthy brain function.

Researchers from the University of York in the UK found that adults who ate a teaspoon of Marmite every day experienced a reduced response to visual stimuli, which is an indicator of increased levels of gamma-aminobutyric acid (GABA) in the brain.

GABA is a neurotransmitter responsible for inhibiting the excitability of brain cells, helping to restore the optimal balance of neuronal activity required for healthy brain functioning. Put simply, GABA “calms” the brain.

Senior author Dr Daniel Baker, of the Department of Psychology at York, and colleagues enrolled 28 adults to their study and randomly allocated them to one of two groups.

The researchers explain that responses in the visual cortex are heavily influenced by GABA, and they point to a previous study that found responses to visual stimuli increased by 300 percent after a GABA inhibitor was administered in rats.

“This ‘response gain’ effect should provide a clear index of GABA availability in cortex, in that increasing GABA concentration should reduce the neural response evoked by visual stimuli to below normal levels,” explain the authors.

Compared with the brains of participants who consumed peanut butter, the brains of subjects who ate Marmite demonstrated a 30 percent reduction in responses to visual stimuli, indicating an increase in GABA levels.

The reduction in visual stimuli responses associated with Marmite intake persisted for around 8 weeks after the study ended, the team notes.

“The high concentration of vitamin B-12 in Marmite is likely to be the primary factor behind results showing a significant reduction in participants’ responsiveness to visual stimuli,” says Dr Baker.

While the researchers are unable to make any firm conclusions about whether Marmite can boost brain function, they believe that their findings indicate that dietary changes may have a long-term impact on brain function.

“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,” adds Dr Baker.

However, the researchers stress that at present, they are unable to make any therapeutic recommendations based on their findings.