Explainer | Why fermented foods are good for your brain, not just your gut, and which are best – experts explain

It’s well known that natto, kefir and other fermented foods and drinks are good for our digestive system, but research suggests they can also boost brain health

A dietitian and a researcher explain the ‘mutual relationship’ between gut and mental health, and reveal which fermented foods are best, and which to beware of

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Kimchi is good for our gut health, but researchers say that it could also be good for our mental health, along with other fermented foods and drinks like sauerkraut, kombucha and miso. Photo: Shutterstock

Published: 4:15am, 13 Jul 2023Updated: 7:15pm, 17 Jul 2023

Blueberries, walnuts, fatty fish and green leafy vegetables are popular “brain foods” that have been linked to better memory and reduced risk of cognitive impairment. Fermented foods can also be added to the “brain health” booster list.

Fermented foods are a source of tryptophan, an essential amino acid that plays a role in the production of serotonin – a chemical that carries messages between nerve cells in the brain and plays an important role in body functions such as mood, sleep, digestion and sexual desire.

A new study, in its initial stages, suggests that some fermented foods may have a bigger impact than others when it comes to brain health, which isn’t surprising seeing as what’s good for our gut is also believed to be good for our brain.

According to one of the study’s researchers – Ramya Balasubramanian of APC Microbiome Ireland, at University College Cork – about 200 fermented foods have the potential to improve gut and brain health.

As well as being good for gut health, fermented foods are also a source of tryptophan, an essential amino acid that plays a role in the production of serotonin. Photo: Shutterstock

Fermented sugar-based products and fermented vegetable-based products, in particular, “are like winning the lottery when it comes to gut and brain health”, Balasubramanian says.

Fermented foods and beverages offer a bounty of benefits for our digestive system because they often contain probiotics, either naturally occurring or added during the fermentation process, says Cyrus Luk, a dietitian and executive committee member of the Hong Kong Dietitians’ Association. Lactobacilli, for example, is a common probiotic strain found in yogurt.