"Whether it's miso, kombucha or yogurt, you've probably heard the buzz about fermented foods and probiotics. In fact, fermented foods are said to help with weight loss, boost immunity and improve overall health. But do fermented foods really live up to the hype? And should you be eating them?
Generally, fermented foods help your digestive tract stay regular and affect your immune system in a positive way, says Jill Nussinow, registered dietitian known as The Veggie Queen and author of The New Fast Food: The Veggie Queen Pressure Cooks Whole Food Meals in Less than 30 Minutes .
"Eating them might lead to weight loss, but it really depends on which fermented foods you are eating, how often and how much," she says. "With so many people taking antibiotics in their lives, they kill the good bacteria. We need something to replace it. If you eat a lot of fiber and whole foods, that helps, but often we need an infusion of the good bacteria to get our system back in order."
So exactly what is it about fermented foods that help our stomachs so much? It's the live cultures, usually bacteria or yeast, that fermented foods contain, says Annie B. Kay , an integrative dietitian, author of Every Bite Is Divine and certified professional-level Kripalu yoga teacher. Some fermented foods act as probiotics.
"Our microflora are a little city of tiny organisms in our large intestine that, when working well, help digest fiber, protect us from things we’d rather not absorb like carcinogens, and keep the bowel healthy," Kay says. "Some nutritionists say that up to half of our immune system activity happens within our microflora."
Eating the right amount of healthy fermented foods can play a role in rebalancing the gut, she says. Examples of fermented foods include yogurts, beer and kombucha tea. In fact, the fermentation process itself is actually much of which gives these foods their unique flavors.
"The fermentation process usually adds some desirable characteristic to the food," Kay says. "In the case of yogurt, the creamy consistency and tanginess. In the case of beer, taste and a beer buzz (alcohol), and with kombucha, that curiously powerful flavor that some folks seem to get attached to."
Although yogurt is the most commonly eaten fermented food in the American diet (be sure to buy yogurt with "live cultures" when you do!), other foods that can be fermented include kefir, cheese, chocolate, tea, wine, sauerkraut or other fermented vegetables, kim chi, truly fermented pickles, miso, tamari and shoyu, Nussinow says.
While there is no standard recommendation for how much fermented food you should consume, a few servings a week is good for overall health. For most people, one eight-ounce container of plain yogurt a day is beneficial, Nussinow says.
"It depends upon you and your tolerance and ability to digest these products," she says. "I try to eat at least a small amount of fermented foods a few times a week. For me, a serving of sauerkraut is about ¼ to ½ cup. A serving of miso is one to three teaspoons."