8 Benefits Of Sauerkraut, FAQs Answered & A Recipe, From RDs

Sauerkraut is finely chopped raw cabbage that has been fermented to create a tangy superfood. A study published in the Global Advances in Health and Medicine says this form of preserving cabbage can be traced back to the fourth century B.C.1 and continues to be a highly nutritious food today. 

According to registered dietitian Ella Davar, R.D., CDN, fermentation was a process used to preserve fruits and vegetables to eat during cold winter months. "However, additional health benefits of fermentation include gut-friendly bacteria, which develops during this process," she adds.

The benefits of sauerkraut go beyond the gut, though. To find out more about the nutritional value, answer commonly asked questions, and learn how to make sauerkraut, mbg consulted registered dietitians to share their knowledge on the fermented vegetable.  

Along with sauerkraut being low calorie (about 30 per cup), these are the notable nutrients and micronutrients in it, according to registered dietitian Maggie Moon, M.S., R.D.: 

"It also offers nourishment that might not show up on a nutrition label, such as probiotics, flavonoids that protect against oxidative damage, and antimicrobial compounds," Moon adds. 

Since it is a fermented food, sauerkraut naturally contains probiotics and prebiotic fiber. "Probiotics have been shown to be effective at managing gastrointestinal symptoms such as constipation, diarrhea associated with antibiotic use and infections, and irritable bowel syndrome (IBS)," registered dietitian Adrienne Ngai, R.D., MSc, CDE, tells mbg. 

Because an estimated 70 to 80% of the immune system lives in the gut, these two systems are inextricably linked, meaning, "any food that supports a healthy gut also supports a healthy immune system," says registered dietitian Abby Cannon, J.D., R.D., CDN.

A randomized control trial found sauerkraut to be one of the only fermented foods clinically shown to help with IBS2. "Surprisingly, the study showed benefits whether the sauerkraut was pasteurized (no probiotics) or not," Moon says. "The researchers think that means it has more to do with the prebiotic fiber than the probiotics." 

Prebiotic fibers help feed good bacteria in the gut (aka probiotics) so they are better able to flourish and thrive, integrative gastroenterologist Marvin Singh, M.D., writes for mbg. These fibers are critical for creating a healthy and balanced microbiome, which supports overall digestive and gut health.

According to the U.S. Department of Agriculture (USDA) food database, 1 cup of sauerkraut3 contains almost 7 grams of fiber, which equals 25% of the daily recommended value.

One cup of sauerkraut contains 15% of the daily recommended value of vitamin K, according to the USDA food database. "Not getting enough vitamin K2 is associated with hardening blood vessels4, which is a risk factor for heart disease," Moon explains. Therefore, eating sauerkraut or other foods rich in vitamin K, may support heart health.

Additionally, studies have shown that probiotics may modestly lower blood pressure5 and improve blood sugar levels6. "For these reasons and because sauerkraut contains fiber7, it can also support heart health," Cannon says.

Probiotics have been shown to manage anxiety and depressive symptoms in people, due to the gut-brain axis8.

While sauerkraut has not been directly associated with stress reduction in humans, "In animal studies where gut microbiomes were wiped out, probiotics from fermented foods calmed down the stress-response system9 that can also harm cognitive function when it's in overdrive," Moon tells mbg.

"There is much scientific evidence documenting the probiotics' potential health effect on gut microbiota ecosystems in relation to brain function10," a review in the Preventative Nutrition and Food Science journal says. This research suggests fermented foods may lead to improvements in memory and cognitive functioning while also supporting mental health.

Just as vitamin K can support heart health, it's also been shown to support bone strength. "Traditional diets high in the form of vitamin K (VK2) found in sauerkraut have stronger bones, fewer fractures, and less bone loss," Moon says. "This is supported by several clinical trials showing that VK2 improves bone mineral density and reduces fractures4."

Store-bought sauerkraut can be good for you as long as it's free of added sugars and preservatives. "It's important that the sauerkraut is, in fact, fermented. The best way to ensure you're consuming fermented sauerkraut is to check the ingredient label," Cannon says. "If vinegar is listed on the ingredients list, it's not fermented." The only ingredients in sauerkraut should be cabbage, salt, and other natural spices and herbs.

"An important point to note is that live probiotic bacteria is destroyed with heating11," Ngai says. "Choose refrigerated sauerkraut instead of pasteurized (heat-treated) varieties you see on the shelf."

When the gut microbiome is unbalanced, introducing good bacteria through probiotics, fiber, and fermented foods can initially lead to bloating or gas. To avoid this, Nichole Dandrea, M.S., RDN, registered dietitian and author of The Fiber Effect, suggests increasing fiber intake by 5 grams each week and drinking plenty of water. Over time, and with improved gut health, gas and bloat should decrease.

The standard serving size of sauerkraut is about 30 grams or somewhere between ⅓ and ½ of a cup.

To avoid painful gas or bloating from the fermented food, Holly Howe, author of Fermentation Made Easy! Mouthwatering Sauerkraut, says to start small. For those who have never eaten fermented foods, she recommends starting "with a sip or two of the brine, and then [moving] on to eating a small bite of the sauerkraut."

Those who eat a variety of fermented foods already can start with one to two forkfuls per day and gradually work their way up to two to three forkfuls with two to three meals, Howe says.

Drinking the brine of the sauerkraut (aka sauerkraut juice) can be good for you—especially if you're trying to build up your tolerance to the fiber, as Howe suggests. The brine contains essentially the same nutrients as the sauerkraut itself, but in a more concentrated form. In fact, Ngai recommends using the brine for a probiotic-rich salad dressing.

You may be used to buying sauerkraut at the grocery store, but if you're looking for a new culinary challenge, try making a homemade version. (Here: a beginner's guide to fermentation.) "The process of making basic sauerkraut is very simple," Davar assures us. Here's how she makes it: 

Here are a few ways Ngai recommends enjoying sauerkraut, as more than a side:

Editor's Note (June 24, 2022): This article was originally published on January 11, 2021. A previous version of this article indicated that one cup of sauerkraut contains 4 grams of fiber, 17% of the recommended daily value. We have since clarified this to indicate that one cup of sauerkraut contains nearly 7 grams of fiber, or 25% of the recommended daily value.