Sauerkraut is fermented shredded cabbage with a tangy, salty flavor.
Despite the German name, it actually originated in China over 2,000 years ago. Nowadays, people all over the world eat sauerkraut.
Sauerkraut typically has just two ingredients: cabbage and salt. Traditionally, the process involves using naturally occurring bacteria to carry out the fermentation of the cabbage.
Commercial sauerkraut manufacturers may use their own “starter cultures” of bacteria for fermentation.
There are a number of health claims about sauerkraut, including improved:
In this article, we’ll look at whether the evidence supports these potential benefits and discuss any risks to consider.
As well as containing nutrients such as fiber, vitamins A, B, C, and K, and a range of minerals, “live” sauerkraut also has a variety of probiotics.
Probiotics are bacteria that scientists have shown can benefit your health.
At ZOE, we know how important a happy gut is for a healthy life.
In fact, ZOE scientists have identified 15 “good” bacteria that are associated with better health and 15 “bad” bacteria that are linked to poor health measures.
With our at-home test, you can learn more about the bacteria in your gut microbiome and what foods to eat to boost the “good” bugs.
1. Gut health
Prof. Christopher Gardner — a member of ZOE’s Scientific Advisory Board and a professor of Medicine at Stanford University, CA — and his colleagues found that eating fermented foods regularly may increase the diversity of your "good" gut microbes.
However, few studies have looked specifically at sauerkraut and gut health.
In one study, 34 people with irritable bowel syndrome ate 75 grams of sauerkraut daily. Half were given sauerkraut with live bacteria, while the other half ate sauerkraut without live bacteria.
After 6 weeks, both groups showed a significant improvement in symptoms, including abdominal pain, bloating, and pooping habits, as well as changes to their gut microbiome.
However, the degree of improvement in symptoms was about the same for both groups.
Because the two groups didn't differ, the researchers suggested that the fiber, rather than the probiotics, was responsible for the improvements.
However, this was a small study, and the researchers didn't look at the effect of eating unfermented cabbage.
More research is needed to find out if sauerkraut can really benefit gut health.
2. Heart health
Similar to gut health, studies looking specifically at sauerkraut and heart health are currently lacking. However, sauerkraut does contain some nutrients associated with better cardiovascular health.
A review of several studies also found that consuming a wide range of probiotics for at least 8 weeks significantly reduced blood pressure. Some commercial sauerkrauts contain as many as 28 different strains of lactic acid bacteria.
Sauerkraut is a great source of vitamin K2, containing 6 micrograms (mcg) of the vitamin per cup.
Other sources of vitamin K2 include natto — fermented soybeans — as well as chicken, eggs, and some hard cheeses.
In one long-term study following 16,000 women, researchers assessed vitamin K2 intake and rates of coronary heart disease over a period of about 8 years on average. They found that for every 10 mcg of vitamin K2 eaten daily, the risk of heart disease was reduced by 9%.
However, it is important to note that these studies focused specifically on vitamin K2, not sauerkraut.
3. Bone health
Research also suggests vitamin K2 is beneficial for bone health. But, again, studies have only focused on vitamin K2 rather than sauerkraut specifically.
Scientists suggest the nutrient promotes strong bones by helping calcium bind to them.
Researchers looking at a range of studies found that people with osteoporosis were 60–81% less likely to get bone fractures if they regularly took vitamin K2 supplements.
In one study, women who had gone through menopause and who added vitamin K2 to long-term vitamin D and calcium supplements had a 25% lower lifetime risk of bone fractures.
However, in this study, the daily dosage of vitamin K2 was 45 milligrams per day, around 150 times more than half a cup of sauerkraut. Research hasn’t explored what the benefit for your bone health would be from the relatively small amount of vitamin K2 in sauerkraut.
Ultimately, current evidence doesn't support the claim that sauerkraut can benefit bone health.
There’s some evidence linking a diet high in cabbage or sauerkraut to a lower risk of certain types of cancer.
One study involved women who had moved from Poland to the United States. The researchers split the participants into groups based on how much raw cabbage or sauerkraut they ate in their adolescent and adult years.
They found that those who had eaten more than three servings per week had a 72% lower chance of breast cancer compared with those who had eaten 1.5 servings or less.
Some research suggests that antioxidants and other plant nutrients in cabbage and sauerkraut may play a part in preventing the cellular damage that can lead to cancer.
However, the current research is very limited in quality and quantity. Much more is needed to make any firm conclusions.
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In one study involving over 700 people, scientists found that those prone to anxiety showed improved symptoms if they regularly ate fermented foods.
However, this research looked at fermented foods in general and didn’t specifically address sauerkraut.
It’s important to note that sauerkraut contains high levels of tyramine. Tyramine can interact dangerously with monoamine oxidase inhibitors (MAOIs), a class of drugs used to treat anxiety and depression.
If you’re taking MAOIs, talk to your healthcare provider before adding sauerkraut to your diet.
Inflammation isn’t always a bad thing. When you hurt yourself or get an infection, it’s your body’s way of protecting you.
But when inflammation goes on for too long, it can be bad for your overall health. This is called chronic inflammation.
Some laboratory studies have suggested that sauerkraut may have anti-inflammatory properties.
However, the results from lab studies using cells won’t necessarily be the same in humans.
Although sauerkraut has substances that seem to have the potential to reduce inflammation, it’s too early to say exactly how eating cabbage or sauerkraut might contribute to this.
7. Immune system
While there isn’t a lot of research, some data suggest that the probiotic strains and nutrients in sauerkraut may benefit immune health.
While there are some interesting links, there isn’t enough evidence at the moment to support the claims that sauerkraut benefits the immune system.
Risks of eating sauerkraut
Although sauerkraut is generally healthy, there may be some risks to consider.
Histamine intolerance. Sauerkraut is high in histamine, which can be responsible for digestive issues and allergy-like symptoms in some people. It’s possible that eating sauerkraut could cause or worsen these reactions.
Drug interactions. Sauerkraut can contain high levels of tyramine, which can interact dangerously with a class of drugs called MAOIs. If you take an MAOI, talk to your healthcare provider before adding sauerkraut to your diet.
High sodium content. If you’re at risk of high blood pressure or are on a low sodium diet, salty sauerkraut may not be the best choice for you. That said, there’s less than 1,000 milligrams of sodium in one cup, so it depends on what else you eat. If in doubt, talk to your healthcare provider.
Where to find sauerkraut
You’ll find sauerkraut in most grocery stores. But not all sauerkraut is created equal.
If you want the potential probiotic benefits while avoiding unhealthy ingredients, here are some things to keep in mind:
Choose “live” sauerkraut. If sauerkraut contains live probiotic bacteria, it should say so on the label.
Look in the chilled section. Like many other probiotic products, stores generally keep live sauerkraut in the chilled section.
Avoid pasteurized sauerkraut. Pasteurization kills bacteria and doesn’t discriminate between the “good” and “bad” kinds.
Look out for added ingredients. If sauerkraut contains preservatives or vinegar, it won’t be live, as these kill bacteria. Also, avoid products with added sugar.
Try health food stores. If you can’t find live sauerkraut in your local grocery store, try a health food store that focuses on fresh foods without unnecessary additives.
How to eat it
There are many ways to eat sauerkraut in both hot and cold foods.
adding it to a salad for a zingy kick
mixing it with rice for added texture and flavor
giving a sandwich some extra crunch and tang
using it as a topping for scrambled eggs or avocado toast
contrasting it with the richness of oily fish like mackerel
Sauerkraut is a versatile food full of essential nutrients like fiber, vitamins, and minerals. Live sauerkraut can also contain probiotic bacteria, which are good for your gut.
Some nutrients in sauerkraut may contribute to improved heart health, bone health, immune function, and inflammation. Eating fermented foods has also been linked to reduced anxiety symptoms.
However, there’s currently no human research that shows direct links between any of these and eating sauerkraut itself.
There are studies linking sauerkraut to a lower risk of certain cancers. However, much more research is needed to understand what’s behind these findings.
If you're pregnant or immunocompromised, you should avoid eating unpasteurized sauerkraut.
If you take MAOIs, have blood pressure concerns, or have food intolerances or allergies, speak to your doctor before eating sauerkraut.
Otherwise, sauerkraut is likely to be a nutritious and healthy addition to your diet. Just remember to choose “live” sauerkraut if you want its probiotic benefits.
At ZOE, we believe in the power of nutrition for a healthy life. In addition to analyzing your microbiome, the ZOE at-home test can see how your body responds to different types of foods. With this information, we can show you which foods are best for you, specifically.
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