Real Talk: What's the deal with fermented foods?

May 4, 2022

Fermented foods are having a moment.

Go to any health food store, read any food blog, follow any diet-focused influencer, and you're likely to hear about fermented foods - yogurt, apple cider vinegar, kombucha, kimchi, kefir, miso, to name just a few.

"Fermented product purchasing is definitely on the rise," says Tedley Pihl, assistant professor of practice for the University of Arizona School of Nutritional Sciences and Wellness (SNSW). "Consumers are looking for better-for-you products to enhance their health."

Fermentation can be described as harnessing the activity of mircoorganisms like mold and bacteria to bring about a desirable change to food or beverages. Humans have practiced fermentation for millennia - think cheese, bread, and beer, for example.

Professor Pihl explains that fermented foods became an integral part of the human diet for a few reasons. "One of the main reasons was to preserve food for survival," she says. "Nutrition is another; fermented foods break down large nutrients or indigestible structures to make them easier to digest. Others include economic value - think about the price of cheese versus the price of milk - and uniqueness - fermentation produces features that cannot be derived in any other way, like the bubbles in champagne and the holes in Swiss cheese."

But what accounts for the recent increase in interest around fermented foods, especially in health and wellness spaces? SNSW associate professor Dr. Melanie Hingle suspects probiotics have something to do with it. "I think when a lot of people think of fermented foods, they're thinking of the ones with probiotics in them," she says. "Probiotics are the live bacteria that we think confer health benefits by helping to populate the gut with so-called 'good bacteria' as they make their way through the digestive tract."

"We know there's a connection between the types of bacteria that inhabit your gut and your health," she continues. "the mechanisms of that are currently being investigated - it's a really important area of research. We still don't have satisfying answers to many questions about food and gut health, including which types of foods contribute to optimal health, and how much of those foods we should be eating. However, we do know that, in general, diets that include some of these foods on a regular basis contribute to an overall healthy eating pattern and support gut health."

Lots of popular fermented foods - yogurt, kefir, kombucha, for example - are rich in probiotics. It's a different story with alcohol.

Alcohol isn't a probiotic - in fact, it has no bacteria at all. "Alcohol and bacteria are incompatible with each other," Dr. Hingle explains. "Bacteria die from being in an alcohol bath." And this may have been one health virtue of foods and drinks produced through fermentation, historically speaking. In some situations, the fermentation process made beverages safer to drink than the available water supply by inhibiting the growth of disease-causing bacteria.

These days, we have water purification methods that prevent us from getting sick. But alcohol may have other health benefits beyond its antibacterial properties.

"Some believe the antioxidants in some alcohols - and even the mild relaxation from alcohol consumption - have health benefits, as in the Mediterranean diet," says SNSW assistant professor of practice Dr. Amy Drescher. "The benefits of alcohol are a topic of debate. For example, some research indicates that breast cancer risk increases with even moderate alcohol consumption, and there may also be a potential decrease in immune function. Research is ongoing."

She notes that fermented foods and beverages are not considered high risk for most people, as long as the fermentation process is conducted properly. "There have been some food-borne illness outbreaks," she says. "This includes dangerous E. coli infections with live probiotic supplements and fermented soy foods. This makes these foods something to use with caution in those with compromised immune function."

University of Arizona students interested in fermentation have the opportunity to get hands-on experience with fermentation methods in a new lab course, NSC 371L, which will be offered for the first time in the Fall 2022 semester. "Students will learn the production processes for a variety of foods and drinks," says Professor Pihl, who developed the course. "They'll learn how to make safe and high quality food products like miso and douchi, kimchi and kombucha, and mozzarella cheese and summer sausage."