The 6 Best Fermented Foods for Brain Health, According to Dietitians

Ever notice how your stomach feels like it's in knots before a big presentation, or how being sad can make you lose your appetite? What affects your mind also affects your gut, and vice versa. This powerful connection is known as the gut-brain axis. 

Emerging research reveals that the brain and gut communicate through multiple pathways. Katherine Brooking, M.S., RD, a New York-based registered dietitian, explains, “Substances produced in the gut by bacteria can travel or send signals up large nerves, such as the vagus nerve, directly to the brain—triggering different brain activities that can alter mood, behavior, memory and cognition.” The process works both ways, as signals from the brain also travel down to the gut, influencing the microbiome. This means, what you eat can also influence your thoughts, emotions and behaviors. 

You may have heard that fermented foods contain beneficial bacteria that support gut health, but it turns out that these foods don’t just benefit our gut—they can also support our brain. Below, we identify the six best fermented foods you should be eating for brain health. 

The 6 Best Fermented Foods for Brain Health 

1. Yogurt

Yogurt is a staple in my fridge, and its versatility makes it an easy addition into any meal or snack. You can whip up a parfait like our Strawberry & Yogurt Parfait for breakfast, blend it into a smoothie, use it to marinate chicken or make a creamy dip. Brooking enjoys Greek yogurt with honey, and research shows this combo can boost good bacteria in the gut.

Amy Kimberlain, RDN, CDCES, a spokesperson for the Academy of Nutrition and Dietetics, recommends yogurt because it contains probiotics (aka beneficial bacteria), which help maintain a healthy gut microbiome. She explains, “Yogurt is good for brain health because it promotes a healthy gut microbiome, supports neurotransmitter production, reduces inflammation and provides essential nutrients that protect and enhance brain function.” 

While research is limited, one study found a potential connection between fermented foods and mood. In mice that lacked gut bacteria, researchers observed worsening symptoms of depression and anxiety, hinting at the role gut health may play in mood regulation. More research on humans needs to be done to further clarify these findings. 

2. Kimchi 

Kimchi is a traditional Korean dish made from fermented vegetables like cabbage and carrots and seasoned with aromatics like garlic and ginger. Not only is kimchi flavorful, but it is also a powerhouse of probiotics, which support both gut and brain health. Studies suggest that the specific probiotics in kimchi may help improve cognitive function and may have neuroprotective effects, potentially reducing the risk of neurodegenerative diseases, such as Alzheimer's disease and dementia.

In addition to probiotics, kimchi is rich in vitamin K, which has been linked to keeping your brain sharp, and antioxidants like vitamin C, which can fight off damaging cells and keep your immune system strong.

Try kimchi in our Gochujang Steak, Kimchi & Cauliflower Rice Bowls for a tasty meal or make your own kimchi: check out our Step-by-Step Guide to Making Kimchi.

3. Kombucha

A trendy fizzy beverage, kombucha is a popular fermented tea that you may have heard can support gut health. Kimberlain explains that kombucha contains probiotics that can help balance the microbiome and add to its diversity of health-promoting bacteria. She says, “A balanced gut can reduce inflammation and promote mental well-being, which can help those managing conditions like anxiety and depression.”

Kombucha is also rich in polyphenols, which can reduce oxidative stress and prevent diseases, including neurodegenerative ones.

Enjoy kombucha for an alcohol-free happy hour beverage or try whipping up your own at home. Follow our guide on How to Make Your Own Kombucha at Home.

4. Miso

Miso is a thick paste made from fermented soybeans. It is commonly used in dishes like soups, used in condiments or can be used in dishes like our delicious 5-Ingredient Miso-Glazed Salmon recipe. This savory paste is not only loaded with umami-rich flavor, but also packed with brain-boosting probiotics. 

Research has found that daily consumption of soy foods, including miso, is linked to a lower risk of cognitive decline and to improved cognitive performance. Brooking adds, “In addition, miso contains folate, niacin and choline, all of which can improve cognition. Plus, the isoflavones in miso may help to reduce inflammation in the brain and body.”

Try incorporating miso into marinades or dressings, like in our Roasted Miso-Garlic Cauliflower Bites, or whip up a batch of our Miso Vegetable Soup for a brain boost. 

5. Tempeh 

Tempeh is a fermented food made from whole soybeans and is packed with protein, delivering a complete plant-based protein source. In addition to its protein power, tempeh also contains probiotics that can support gut and brain health.

“Emerging research indicates that fermented foods may benefit the gut-brain axis and potentially improve memory, cognition, anxiety and depression,” says Brooking. She also adds, “Tempeh contains bioactive compounds, such as acetylcholine, that may positively impact memory function.”

Tempeh has a nutty flavor and dense texture, which can elevate any dish. For your next taco night, try our Tempeh & Mushroom Tacos or give our Sesame-Honey Tempeh & Quinoa Bowl a taste. 

6. Kefir 

Kefir is a fermented drinkable beverage product that is made with milk or water and is rich in live probiotic cultures. It has a thick consistency similar to a milkshake and can be enjoyed on its own or used as a base in smoothies such as our Berry-Kefir Smoothie. 

Kimberlain points out a study that investigated the effects of kefir on memory in adults. Participants who consumed 1 cup of kefir daily for four weeks showed improvements in their relational memory, which is the ability to remember and connect information about people, places, events and objects. Additionally, those consuming kefir experienced an increased concentration of Lactobacillus in their gut. A brain- and gut-health superstar!

Enjoy kefir by the glass or add it to overnight oats, smoothies, creamy salad dressings or soups. 

Other Tips for Supporting Brain Health 

In addition to increasing your intake of fermented foods, there are several other things you can do to support your brain health. Below are tips from our two dietitians on what else you can do to help promote healthy cognitive function.

• Stay Active: Both experts recommend regular physical activity to support brain health. Kimberlain states that physical activity increases blood flow to the brain, promotes the growth of new brain cells and enhances cognitive function. Brooking recommends at least 30 minutes most days of the week to help improve memory, thinking and problem-solving.  
• Get Enough Sleep: Our experts say sleep is critical to brain health and recommend at least seven to nine hours per night. Sleep helps us learn new skills and store memories, and getting enough can also improve focus and concentration. 
• Be Social: Maintaining strong social connections can help keep your brain chugging along. Kimberlain says engaging in meaningful social activities can improve mood, reduce the risk of depression and protect cognitive function.
• Challenge Your Brain: Try a mentally stimulating activity like puzzles, reading or learning a new skill, which can help keep your brain sharp, says Kimberlain.
• Eat a Balanced Diet: Fuel your brain with a diet rich in vegetables, fruits, whole grains, legumes, lean sources of protein and healthy fats, says Brooking. 

The Bottom Line

The connection between our brain and gut highlights the importance of how what we eat can impact our entire body, including our brain. By incorporating fermented foods like kimchi, kefir, yogurt, miso, tempeh and kombucha regularly into your diet, you can promote both gut and brain health. In addition, prioritizing a balanced diet, being social, getting enough sleep and staying physically active are essential for supporting a healthy brain.