Kombucha and yogurt are as ubiquitous as granola at health-food stores these days. You may even know someone (or be someone) who is making her own kimchi, cheese, beer or pickles at home. Fermentation may seem like a modern trend among health-conscious and DIY types, but the practice has been around for a very long time.
Cultures throughout the world have utilized fermentation, a process of breaking down carbohydrates (sugar, for example) into acid or alcohol in the absence of oxygen for thousands of years. It happens naturally under certain conditions and can be promoted by introducing specific microorganisms—a yeast, mold or bacteria culture—into the food. Yeast is used to make beer, for example, and lactic-acid-producing bacteria are used to produce yogurt.
Before refrigeration, fermentation was an important method of food-preservation. The acids resulting from the process created an environment hostile to the microbes that lead to spoilage. And, the introduced or native bacteria cultures in these foods protected their turf, in a sense, against unwelcome microorganisms that might otherwise take over, spoiling the food and potentially making the unlucky eater sick.
“Fermented foods can have higher quantities of B vitamins, which are involved in energy production, mood regulation and other important processes in the body.”
Fermented foods offer nutritional benefits, too. “Fermentation starts pre-digestion of the food itself, so it helps us break down and absorb nutrients in foods,” explains Dr. Courtney Jackson, N.D., lead physician of
the National College of Natural Medicine’s ECO (Ending Childhood Obesity) Project based in Portland, Oregon. For example, fermentation enhances calcium and zinc absorption from whole grains and dark leafy green vegetables by breaking down oxalic acid and phytic acid, naturally occurring components that can otherwise inhibit absorption of these minerals.
The process of fermentation even boosts the vitamin content of food. “Fermented foods can have higher quantities of B vitamins,” says Jackson, “which are involved in energy production, mood regulation and other important processes in the body.” And there’s more good news: When we eat live-culture foods, their beneficial bacteria enhance our intestinal environment and fend off disease-causing bacteria. “It’s important that our gut has regular exposure to friendly bacteria,” Jackson says. “This helps keep the gut and immune system strong and in check.”
Research on the health benefits of fermented foods is somewhat lacking, with the exception of studies on probiotics, specific strains of bacteria that are typically cultured in laboratories and considered by some to be more beneficial than lactic acid bacteria occurring naturally in foods. (Lactobacillus strains added to yogurt are among the most common; look for ‘live, active cultures’ on the label.) An impressive body of research has shown probiotics to be helpful in treating and preventing irritable bowel syndrome (IBS), diarrhea, constipation and other gastrointestinal maladies. These “good” bacteria have also proven beneficial in treating vaginal infections, high blood pressure, high cholesterol, and more.
Beyond their health benefits, fermented foods have distinctive sour or tangy flavors and strong aromas that many people love (and others loathe). “Stinky” cheeses, kimchi, kosher dill pickles, tempeh, sauerkraut—these are among the tasty fermented foods on offer in the average health-food or specialty grocery store.
If you’re ready to try fermenting at home, The Art of Fermentation by Sandor Ellix Katz (Chelsea Green Publishing, 2012), is an invaluable resource. Peruse the bulletin board at your local food co-op to learn first-hand. “That’s how this knowledge has traditionally been passed on,” says Jackson, “through family secrets and word of mouth.” Think of it as an opportunity to carry on an age-old—and healthy—tradition.