The surprising mental and gut health benefits of fermented foods

Fermented foods. (Getty Images)
Do fermented foods have benefits for mental health? (Getty Images)

If you're anything like me, when you hear the words 'fermented foods', you'll automatically think of the fermented egg in an eating bushtucker trial in ITV's I'm A Celebrity Get Me Out Of Here.

However, while that particular fermented offering may induce gagging of epic proportions, there are plenty of, far tastier, fermented foods on the market, which come with a variety of health benefits particularly for the gut, but also for wellbeing.

New research published in the journal Neuroscience and Biobehavioral Reviews, has linked fermented foods with mental health benefits via the gut/brain connection.

What are fermented foods and how could they improve mental health?

Traditionally, the process of fermentation has been used to preserve foods. However, as well as lasting longer, fermented foods often contain a variety of ‘good’ bacteria which can be beneficial for our gut health.

We've long known that what you eat could have an impact on how you feel and more recently there has been an increasing interest in the 'microbiota-gut-brain axis' — the link between the brain and the digestive system.

Just like the brain, the gut has a nervous system of its own, and what we eat can significantly impact the levels of certain hormones and neurotransmitters within the body.

"We know through research that the gut and brain are able to communicate through the gut-brain axis, not just brain to gut but gut to brain as well through the vagus nerve," explains gut health expert Lauren Johnson Reynold aka London Wellness Coach.

"We also know that the diversity of beneficial bacteria within the gut microbiome can have an effect on mental health."

Fermented foods, such as kefir. (Getty Images)
Research has linked fermented foods, such as kefir, to mental health benefits. (Getty Images)

With regards to fermented foods, such as sauerkraut, kimchi, kefir and kombucha, specifically, Reynold says they are naturally populated with a range of gut bacteria that help to keep the delicate balance within the gut and also contain specific 'ingredients' to improve mental health.

"For example, fermented foods are a source of tryptophan, an amino acid used in the production of serotonin, a key messenger in the brain which impacts several aspects of brain function, including mood," she explains.

"Lactobacillus, a bacteria found in fermented foods and live yoghurt, can also help the body manage stress and may even help prevent anxiety and depression."

Reynold says as there are already studies on the role of probiotic supplements in treating anxiety and depression, it stands to reason that foods containing naturally occurring probiotics, such as fermented foods, could have the same impact.

"One thing to note, however, is that while fermented foods provide the 'good' gut bacteria, it's fibre that feeds them so it's important to eat a diet rich in a variety of plant foods to get the best from all the fermented goodness"

Fermented foods. (Getty Images)
Fermented foods have benefits for gut health. (Getty Images)

The most recent research

Taking earlier peer-reviewed scientific studies, such as the research mentioned by Reynold, which links increased fermented food consumption with lower risk for anxiety and depression and stress into consideration, a new study, by researchers at APC Microbiome, University College Cork, and Teagasc (Ireland’s Agriculture and Food Development Authority), set out to try to discover, which fermented foods might benefit our brains the most.

While further research is needed, the research team found positive results for fermented foodie fans of kraut, kimchi, kombucha, yoghurt, miso, kefir and other fermented foods.

"I expected only a few fermented foods would show up, but out of 200 fermented foods, almost all of them showed the ability to exert some sort of potential to improve gut and brain health," one of the study authors, Ramya Balasubramanian, explained in a press release last year when the study was in its early stages.

Commenting on the final findings of the research, released last week, Ben Vear, CEO and co-founder of www.drinklivingthings.com said: "The recent study by the Neuroscience and Biobehavioral Reviews highlights an ever-increasing interest in fermented foods and their impact on gut and mental health.

"The study emphasised that the microbiota-gut-brain axis is an emerging process in which our diet, particularly fermented foods, can influence our overall wellbeing."

Vear explains this is because fermented foods are rich in probiotics and prebiotics, which are beneficial bacteria that contribute to healthy gut flora and hormones.

"The research also suggests the link that having a diet rich in fermented food can positively impact your mental health and cognitive functions from the production of serotonin in the gut," he continues.

"There’s a reason people refer to the gut as being a ‘second brain’ and there are many more studies that highlight correlations between good gut health and good mental health."

Kombucha. (Getty Images)
Kombucha is just one example of a fermented food. (Getty Images)

Vear says people looking to improve their mental health should take a look at their diet and other things they can do to boost their gut health.

"From the food and drinks we consume, through to the exercise we take part in, there are many ways to contribute towards good gut health," he explains.

"Regular exercise, especially outdoors, is known to reduce symptoms of anxiety and depression. It triggers the release of endorphins leading to an improved sense of well-being and a reduction in feelings of stress and anxiety, with some studies suggesting exercise positively modifies the gut microbiota.

"Combining an active routine with a diet rich in fermented foods and drinks creates an excellent foundation towards improving your mental health."

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