Friday, 28 April 2017

Marmite, GABA, and Improved Brain Function

Marmite on toast ready for me to eat
Photo by Linda Crampton

A Potentially Helpful Sandwich Spread

Marmite is a dark brown spread with a strong taste that some people love and others hate. Research performed by scientists at the University of York in Britain suggests that eating marmite can be beneficial for brain function, possibly by stimulating the production of a chemical known as GABA.

Half of the subjects in the British experiment ate a teaspoon of marmite every day for a month in addition to their normal diet; the other subjects added a daily teaspoon of peanut butter to 
their diet instead of marmite. At the end of the month, the researchers found that the people who ate marmite had an approximately thirty percent reduction in their brain's response to visual stimulation caused by an image of flickering stripes. This was demonstrated by detecting the electrical activity in the brain via electroencephalography, or EEG.

What Is GABA?

The researchers believe that the decreased brain activity in the subjects occurred because the marmite stimulated the production of GABA. "GABA" is an abbreviation that stands for gamma-aminobutyric acid. The chemical is a neurotransmitter. Neurotransmitters control the passage of a nerve impulse from one neuron (nerve cell) to another. Some transmit the impulse and are said to be excitatory. Others stop the transmission and are said to be inhibitory. GABA is an inhibitory neurotransmitter. It night sound bad that a chemical stops the passage of a nerve impulse, but that's exactly what sometimes needs to happen in order to quell overactivity in the nervous system. 

GABA is often low in people with epilepsy, as is taurine. Its role in the disorder isn't fully understood, however. It's very important that someone with epilepsy or a seizure disorder doesn't take GABA or taurine supplements without their doctor's supervision. According to the University of Maryland Medical Center, there is no scientific evidence that supplements containing the chemicals will reduce the number of seizures. 

DO NOT take taurine or GABA supplements without your doctor's supervision. DO NOT take taurine or GABA if you have a history of bipolar disorder, or if you take psychoactive medications. (Quote from the University of Maryland Medical Center)

Some Unanswered Questions

The results of the marmite experiment are interesting and could be important, but there are some unanswered questions relating to the research.

  • Although the researchers think that the vitamin B12 in the marmite was the helpful component of the spread (because it triggered the production of GABA), this wasn't tested. Another substance may have been responsible for the benefit. It's also possible that a combination of chemicals produced the benefit.
  • The proposal that the marmite exerted its effect by triggering GABA production wasn't tested. 
  • Only twenty-eight people were involved in the research (fourteen in each group). The experiment needs to be repeated with a larger sample size.
Thickly spread marmite
Photo by TheJackal, CC BY-SA 3.0 License

The Nature of Marmite 

Marmite is a yeast extract. For some people, eating a whole teaspoon of the spread all at once would be difficult because of its strong and often overpowering taste. I love marmite myself, but I spread it very thinly on my bread, as shown in my photo at the start of this article. I would find it very hard to eat the thick layer shown in the photo above. I suspect that some marmite haters might like the product if they ate a thin layer instead of a thick one

The marmite that's sold in Britain contains added B vitamins, including vitamin B12. The version that's sold in Canada, where I live, doesn't contain these additions. I can get British marmite only if I go to a food import store instead of my local supermarkets. I sometimes do this, but I usually buy the product locally. It would be nice if it was beneficial for brain health as well as being tasty. It would also be nice to know if the marmite version with added vitamins is necessary in order to get the special health benefit discovered in the research.


Marmite may affect brain function from ScienceDaily

Marmite may be brain food from CTV News

Seizure disorders from the University of Maryland Medical Center