February 06, 2024
Angela Wilhelm/Asheville Citizen-Times/ USA TODAY NETWORK
Eating yogurt, kimchi, tempeh and other fermented foods may not only improve gut health, but also provide a mental health boost, researchers say.
Fermented foods like sourdough, kimchi and kombucha have been touted for their purported physical health benefits, but scientists say they can benefit mental health, too.
Fermentation is a process that breaks down carbohydrates like sugars and starches into alcohol and acids to preserve the shelf life of foods. Fermented foods have been found to aid digestion, boost the immune system and reduce the risk of heart disease.
A new study, published in Neuroscience & Biobehavioral Reviews, shows that nearly 200 fermented foods also can aid mental health thanks to a connection between the brain and digestive system.
This connection, known as the gut-brain axis, links the cognitive and emotional centers of the brain to the peripheral intestinal functions. The food people eat can boost the levels of certain hormones and neurotransmitters in the body, affecting their moods.
Through the gut-brain axis, substances produced by gut bacteria can send signals to the brain, prompting brain activities that impact mood, behavior, cognition and memory. The brain also can send signals to the gut that impact gut bacteria.
"We know from previous studies that there is a proven gut-brain axis and that this, therefore, links diet directly to the brain and its behavior based on the health of our microbiota," Dr. Nicole Avena, an assistant professor of neuroscience at Mount Sinai School of Medicine in New York City, told Medical News Today. Avena was not involved in the study.
Many fermented foods naturally have probiotics – which help increase the amount of healthy gut bacteria – including miso, yogurt, kombucha, kefir, kimchi, tempeh, sourdough bread, sauerkraut, pickles and some cheeses. Some fermented foods also may contain prebiotics, which help feed healthy gut bacteria.
Having an abnormal composition of gut bacteria has been linked to depression, anxiety, dementia and Parkinson's disease. A study published last year found that people who took probiotics every day had reduced anxiety levels and symptoms of depression.
