Fermented foods have long been culinary staples, but they continue to get attention for their health benefits since they’re rich in antioxidants and are anti-inflammatory. They’re also an excellent source of probiotics, dietitian Edwina Clark tells Yahoo Life. But what exactly are fermented foods and why are they good for you? First, fermentation involves yeast or bacteria breaking down the carbohydrates and sugars in a food, helping to preserve it, while enhancing its flavor, texture and nutritional content. While most studies on fermented foods and health are small, research shows that consuming them can come with some health benefits.
In one study, researchers found that people who ate a diet high in fermented foods, averaging 6 servings daily for 10 weeks, experienced an increase in microbiota diversity — think good gut health — and decrease in markers of inflammation compared to those who ate a high fiber diet, averaging about 45 grams of fiber daily, with no fermented foods.
But before you start adding these foods to your diet, Kristie Leigh, dietitian and director of health and scientific affairs at Danone North America, points out that not all fermented foods have the same benefits. “Some of the cultures in fermented foods are simply there for texture, taste or preservation properties and do not provide the specific health benefits that probiotics do,” she tells Yahoo Life. Others might be killed or removed during pasteurization or cooking. So if you’re after probiotics, Leigh recommends looking for strains listed on the fermented food labels, such as lactobacillus, to make sure they contain live cultures. Also worth noting: Given that salt is important in fermentation, Clark recommends eating fermented foods in moderation if you’re on a salt-reduced diet.
Here’s what experts say are the top seven fermented foods to include in your diet:
Probiotic Greek Yogurt/Icelandic Skyr
Yogurt’s multitude of health benefits include both reducing the risk of type 2 diabetes and improving fasting blood glucose and antioxidant status, which plays a role in protecting cells from damage, in those who already have type 2 diabetes. Yogurt also helps lower blood pressure, promotes an anti-inflammatory environment in the gut and reduces the risk for breast and colorectal cancer and osteoporosis.
“In addition to offering probiotics, Greek yogurt and skyr are rich sources of protein, calcium, B vitamins, phosphorus, potassium and zinc,” says Clark. And for those with difficulty tolerating lactose, the live and active cultures in yogurt may improve lactose digestion.
“Dairy foods can also help buffer stomach acids, which is important if you’re eating a probiotic yogurt because it increases the chance that the probiotics will survive to the intestine, where they typically provide their benefit,” says Leigh.
Kefir
“Kefir is a probiotic powerhouse relative to other fermented foods both in terms of quantity and number of strains,” says Clark. Just like yogurt, kefir is a fermented milk product, rich in probiotics, protein, calcium and B vitamins and is low in lactose. But, as Christina Badaracco, culinary medicine consultant and author, tells Yahoo Life: “Kefir contains a more complex composition of microbial species” — think a wider variety of probiotics — “than does yogurt and has fermented for longer, so it has been suggested to promote better colonization” — meaning the strains stick around longer in your gut — “and higher nutrient content.”
It may be a useful food in managing metabolic syndrome — a group of health conditions that increase the risk of heart disease, stroke and type 2 diabetes — as one study showed drinking 180 ml of kefir daily increases apolipoprotein A1, a key protein in HDL cholesterol that helps with lowering “bad” cholesterol and the risk for cardiovascular disease. A meta analysis also found that consuming probiotic fermented milk products like kefir has a positive influence on total and LDL cholesterol, particularly in men or when multiple strains of probiotics are consumed for at least eight weeks.
Kombucha
Kombucha, a fermented, carbonated tea known for its sour taste, is made from a combination of tea, sugar and SCOBY, or symbiotic cultures of bacteria and yeasts. It’s high in antioxidants, including polyphenols and flavonoids, and has anti-inflammatory and antibacterial properties. And despite its sugar content, kombucha may actually help lower blood glucose levels.
While it’s a hydrating alternative to soda and alcoholic beverages, be aware that the amount of probiotics and polyphenols can vary depending on the tea type used and how long it’s fermented. Research suggests green tea kombucha has the highest antioxidant potential.
Kimchi
A traditional Korean dish, kimchi is most commonly made up of fermented napa cabbage and might include daikon radish, carrots, garlic, ginger, scallions, fish sauce and chili flakes. It’s high in vitamins A, B6, B12, C and K, calcium, iron, phosphorus and magnesium.
“Kimchi is like a superhero for your gut,” Julie Pace, a dietitian and functional nutrition expert, tells Yahoo Life. “It’s packed with lactobacilli bacteria, a probiotic powerhouse that can work wonders for digestion and can ease gastrointestinal issues like IBS and colon inflammation.”
There are several other benefits as well: Lactic acid bacteria, which is found in kimchi, is associated with lowering cholesterol. And recently, researchers observed that eating up to 3 servings of kimchi daily was associated with an 11% lower obesity risk compared to eating less than 1 serving a day. Specifically, radish kimchi was associated with a lower prevalence of abdominal obesity in both men and women.
Sauerkraut
Popular in European and Asian countries, sauerkraut is fermented cabbage that is loaded with lactic acid bacteria and is high in fiber. Research shows that sauerkraut has antioxidant, anti-inflammatory and anticancer properties. While there is some concern that pasteurization of sauerkraut kills live cultures and reduces these probiotic benefits, research shows that some heat-killed cells still demonstrate antioxidant activity. In a small study of IBS patients in which half consumed pasteurized sauerkraut and the other half unpasteurized sauerkraut for six weeks, all study participants experienced improved gut microbiota and IBS symptoms.
Miso
While miso is most commonly used as a flavoring for miso soup, it’s actually a traditional Japanese paste that is produced in a two-stage fermentation process of soybeans. “Miso stands out as a top-tier fermented food, filled with beneficial nutrients like soy proteins and isoflavones,” says Pace. Its numerous health benefits include antidiabetic, antioxidative, anti-inflammatory, anticancer and antihypertensive properties. Research from Japan also links daily consumption to reduced risks of stomach cancer, heart disease, mortality and gastroesophageal reflux disease (GERD) symptoms.
Tempeh
Tempeh is a traditional Indonesian fermented food typically made from soybeans. Each 3 oz. serving boasts about 17 grams of protein, 6 grams of unsaturated fat, calcium, potassium, iron, magnesium, phosphorus and B vitamins.
Tempeh contains paraprobiotics, which are cooked probiotics that still have anti-inflammatory and antioxidant properties. Its high content of isoflavones are associated with protecting the nervous system, specifically reducing the risk of dementia and having protective effects against Alzheimer’s and Parkinson’s diseases. Research on tempeh also shows improved gut health, strengthened immunity, improved liver function, lowered cholesterol and reduced blood pressure.
