Many countries around the world have their own staple fermented foods, ingrained in culture and diet. It can’t be a coincidence that this has happened time and time again, so it seems logical that fermented foods offer more than just a method of preservation.

Diet can greatly influence mental health, and previous research has shown that some foods are especially good at positively influencing the brain. Fermented foods are a source of tryptophan, a key amino acid for the production of serotonin, a brain messenger that influences various aspects of brain function, including mood.

Food can also contain other brain messengers (known as neurotransmitters) in their raw form. Not surprisingly, then, research has shown that consuming fermented foods can have a number of short- and long-term impacts on brain function, including reducing stress.

But which foods influence mental health the most? Researchers at APC Microbiome, University College Cork and Teagasc (Irish Food and Agriculture Development Authority) in Ireland are currently working on a large study to finally answer this question.

Researcher Ramya Balasubramanian and the APC team compared sequencing data from more than 200 foods from around the world, looking for various metabolites known to be beneficial for brain health.

The study is still in its early stages, but researchers are already surprised by the preliminary results.

“I expected only a few fermented foods to show up, but out of 200 fermented foods, almost all showed the ability to exert some sort of potential to improve gut and brain health,” explains Ramya.

More research is needed to find out which fermented food groups have the greatest effects on the human brain, but the results show an unexpected victor.

“Sugar-based fermented products and vegetable-based fermented products are like winning the lottery when it comes to gut and brain health,” says Ramya.

For the expert, “as much as sugar-based products are demonized, fermented sugar takes the raw sugar substrate and turns it into a plethora of metabolites that can have a beneficial effect on the host.”

So, for Ramya, even though it goes by the name “sugar,” if you do a final metabolomic screening, “sugar is used by the microbial community present in the food and is turned into these beautiful metabolites that are ready to be selected by us for further study.

The next step is to conduct those investigations. It plans to put its top-ranked fermented foods through rigorous testing with an artificial colon and various animal models to see how these metabolites affect the brain.

Thus, they hope that the public can use these preliminary results and consider including fermented foods in their diet as a natural way to support their mental health and general well-being.