Previous studies have found a connection between diet and mental health. Foods like blueberries, salmon, and green leafy vegetables may protect you against dementia, and we also know that a diet containing lots of ultra-processed foods is linked with depression. 1,2

Fermented foods have been used for years to aid in preserving food. New research suggests they may also be good for your brain. Consuming fermented foods may have long-and short-term effects on brain function such as stress reduction. What’s the scoop on SCOBY?

Scientists at APC Microbiome, University College Cork, and Teagasc (Ireland’s Agriculture and Food Development Authority) in Moorepark, Cork, Ireland, are studying data from over 200 foods from around the globe to find various metabolites that may benefit brain health.

The study isn’t finalized but early results indicate that fermented foods are rising to the top as several show potential to improve both gut and brain health. Further studies are necessary to totally understand which fermented foods have the best impact on brain health. 3

While fermented sugar-based products are often demonized, when raw sugar is fermented, it changes, and a variety of beneficial metabolites may be produced.

Kombucha, for example, contains B vitamins, polyphenols, and acetic acid. 4 The amino acid tryptophan is found in fermented foods and is key to producing serotonin, a neurotransmitter in the brain that impacts mood and other aspects of brain health.

Fermented vegetable products also have a lot of potential benefits for brain health. Kimchi and sauerkraut are both fermented though may need to be limited by those with hypertension due to their high sodium content.

The study authors plan to use her top-ranked fermented foods in further testing using an artificial colon and animal models to evaluate the impact on the brain. She hopes that individuals will use her early study results and consuming fermented foods as a way to boost their mental health and overall well-being.

Below are three fermented foods to try:

·         Kefir- a fermented dairy-based drink. Peptides, bioactive compounds, and bacteria strains occurring in kefir, can alter gut microbiota composition, low-grade inflammation, and intestinal permeability. Kefir may affect the gut-brain axis and boost brain health. 5

·         Kombucha- a fizzy, fermented drink made from black tea and “SCOBY” (symbiotic culture of bacteria and yeast). Kombucha is sold commercially but some people make their own at home.

·         Yogurt- subjects consuming yogurt containing probiotics have been found to have fewer menopausal symptoms including anxiety, hot flashes, depression, and LDL cholesterol compared to a control group. 6

Lisa Andrews, MEd, RD, LD

References:

1.    Bear TLK, Dalziel JE, Coad J, Roy NC, Butts CA, Gopal PK. The Role of the Gut Microbiota in Dietary Interventions for Depression and Anxiety. Adv Nutr. 2020 Jul 1;11(4):890-907. doi: 10.1093/advances/nmaa016. PMID: 32149335; PMCID: PMC7360462.

2.    Agarwal P, Leurgans SE, Agrawal S, Aggarwal N, Cherian LJ, James BD, Dhana K, Barnes LL, Bennett DA, Schneider JA. Association of Mediterranean-DASH Intervention for Neurodegenerative Delay and Mediterranean Diets With Alzheimer Disease Pathology. Neurology. 2023 Mar 8:10.1212/WNL.0000000000207176. doi: 10.1212/WNL.0000000000207176. Epub ahead of print. PMID: 36889921.

3.    Microbiology Society. "Kombucha to kimchi: Which fermented foods are best for your brain?." ScienceDaily. ScienceDaily, 13 April 2023. <www.sciencedaily.com/releases/2023/04/230413154458.htm

4.    Abaci N, Senol Deniz FS, Orhan IE. Kombucha - An ancient fermented beverage with desired bioactivities: A narrowed review. Food Chem X. 2022 Apr 6;14:100302. doi: 10.1016/j.fochx.2022.100302. PMID: 35434600; PMCID: PMC9011011.

5.    Peluzio MDCG, Dias MME, Martinez JA, Milagro FI. Kefir and Intestinal Microbiota Modulation: Implications in Human Health. Front Nutr. 2021 Feb 22;8:638740. doi: 10.3389/fnut.2021.638740. PMID: 33693024; PMCID: PMC7938729.

6.    Shafie M, Homayouni Rad A, Mirghafourvand M. Effects of prebiotic-rich yogurt on menopausal symptoms and metabolic indices in menopausal women: a triple-blind randomised controlled trial. Int J Food Sci Nutr. 2022 Aug;73(5):693-704. doi: 10.1080/09637486.2022.2048360. Epub 2022 Mar 9. PMID: 35264075.