Is kefir healthy? Separating fact from fiction

Category: fermentation,Learn

You’ve heard about kefir of course. This tangy, fermented milk drink has been around for thousands of years, but it’s recently been making waves in the health food world. But is kefir really as healthy as some claim? Let’s dive in and separate the facts from fiction.

What exactly is kefir?

Kefir is like a cross-over between yogurt and buttermilk, with a slight fizz. It’s a fermented milk drink that can range from creamy and mild to tangy and sour, depending on how long it’s fermented.

Milk kefir is generally a bit thinner than yogurt and has a sharper, sometimes even slightly cheesy and slightly alcoholic taste.

Milk kefir vs water kefir

But don’t confuse milk kefir with water kefir! While both are fermented drinks made with “grains,” water kefir is a sugar-based soda, while milk kefir is dairy-based. They share a name, but that is where the similarity ends. Looking for waterkefir? Check out our water kefir grains here.

The secret behind kefir’s magic: the grains

The real stars of the show are the kefir grains. No, they’re not actual grains – they look more like tiny, gelatinous cauliflower florets. These grains contain a complex mix of bacteria and yeasts that work together to transform milk into kefir.

The main players are Lactobacillus bacteria (especially L. kefiri), which give kefir its sour taste, various yeasts that provide a mild carbonation and a hint of alcohol and kefiran, a special substance that gives kefir its creamy texture.

Is Kefir healthy? Separating the facts from fiction

With kefir’s rising popularity, there are plenty of health claims floating around. But which ones actually hold up under scientific scrutiny? Let’s break it down:

7 Proven benefits of drinking milk kefir:

  • Milk kefir improves digestion and lactose tolerance: If you’re lactose intolerant, kefir might be your new best friend. The probiotics in kefir help break down lactose, making it easier to digest than regular milk. Studies have shown that people with lactose intolerance can often consume kefir without experiencing the usual digestive discomfort associated with dairy products.

  • Milk kefir has antimicrobial power: Kefir is like a superhero fighting off bad bacteria in your gut. It’s been shown to inhibit nasties like Salmonella, H. pylori, and E. coli. This antimicrobial effect is due to the production of organic acids, hydrogen peroxide, and bacteriocins during the fermentation process. These compounds can help prevent gastrointestinal infections and maintain a healthy gut microbiome.

  • Milk kefir helps with blood sugar control: If you’re watching your blood sugar, kefir might help. Some studies have shown it can aid in managing diabetes. For instance, a clinical trial with diabetic patients found that regular kefir consumption led to improved fasting blood glucose and HbA1c levels. The probiotics in kefir may help improve insulin sensitivity and reduce inflammation, both of which are beneficial for blood sugar control.

  • Milk kefir has many anti-inflammatory effects: Feeling inflamed? Kefir’s bioactive compounds might help calm things down. Research has shown that kefir can reduce markers of inflammation in the body. This anti-inflammatory effect is attributed to the various peptides and other bioactive substances produced during kefir fermentation. These compounds can help modulate the body’s inflammatory response, which could be beneficial for people with inflammatory conditions.

Probable benefits (yet, more research needed)

  • Milk kefir could reduce your cholesterol: The jury’s still out on this one. Some studies say ‘yes’, others say ‘no significant effect’. For example, a study published in the Journal of Dairy Science found that kefir consumption led to a decrease in total cholesterol and LDL cholesterol in overweight individuals. However, other studies have not shown the same effect. The discrepancy might be due to differences in kefir preparation and study designs. Future studies will have to decide of this is true.

  • Milk kefir may help in blood pressure regulation: There’s promising evidence, but we need more comprehensive trials to be sure. Some studies have observed that kefir consumption can lead to a reduction in both systolic and diastolic blood pressure. This effect might be due to bioactive peptides formed during kefir fermentation, which could have ACE-inhibitory properties similar to some blood pressure medications. Very interesting stuff, but don’t rely on kefir yet to lower your blood pressure!

  • Milk kefir can help you manage your weight: Early studies suggest kefir might help with weight loss, especially in overweight individuals. A few small studies have found that including kefir in a calorie-controlled diet may lead to greater weight loss and body fat reduction compared to a similar diet without kefir. The mechanisms behind this are not fully understood but may involve improved digestion and metabolism. Don’t throw out your gym membership just yet – more research is needed.

Unproven claims about the health benefits of drinking kefir

Unfortunately, there are a lot of claims about the health benefits that can be found online or in books, that have not been substantiated by evidence. Let’s no partake in the spreading of untruths:

Milk kefir starter culture

  • Milk kefir does NOT prevent cancer: While there’s some lab evidence, there’s no conclusive proof in humans. Some in vitro (petri dishes) and animal studies have suggested that kefir might have anti-carcinogenic properties. However, these effects have not been demonstrated in human clinical trials. Always follow your doctor’s advice!

  • Milk kefir does NOT help your skin health: Some people swear by kefir for their skin, but we don’t have solid scientific evidence yet. Anecdotal reports and preliminary studies suggest that kefir might improve conditions like eczema and atopic dermatitis, possibly due to its probiotic content and anti-inflammatory properties. However, robust clinical trials are lacking, so right now it’s hard to substantiate these claims scientifically.

  • Milk kefir is NOT a miracle weight loss product: Sorry, folks – kefir isn’t a magic weight-loss potion (nothing is). While it might help as part of a balanced diet, there’s no proof that kefir itself has a significant fat-burning or weight-reducing effect. Any weight loss benefits are likely due to its role in supporting overall digestive health and potentially improving metabolism.

  • Milk kefir is NOT a fountain of youth or product that increased general well being: While kefir can contribute to a healthy diet, claims about extended lifespan are unproven. The historical and traditional use of kefir often associates it with improved overall health and longevity, but specific claims about its ability to extend lifespan are not scientifically proven. And well being, what the hell is that anyways?

  • Milk kefir is NOT an allergy cure: some people report improvements in seasonal allergies, but there’s no scientific backing for this claim yet. The effects of kefir on allergic reactions are still unknown, and more research is needed to understand if and how kefir might influence allergic responses.

 Is milk kefir safe to drink?

Generally, yes! But there are a few things to keep in mind: If you’re allergic to milk, steer clear. You might experience some temporary digestive issues when you first start drinking kefir due to the high levels of beneficial microbes that your gut needs some adjusting to.

There’s a tiny amount of alcohol in kefir (0.5-2%), so be aware if you’re sensitive or avoiding alcohol.

If you’re on immunosuppressant medications, check with your doctor first. Some interactions may occur.

If you’re making kefir at home, make sure to keep everything clean to avoid any unwanted bacteria crashing the fermentation party. Use your nose and eyes!

A few signs that you’re kefir is not safe to drink

Like any other home fermented product, it is wise to keep an eye out for signs of spoilage or infection. Here are a few signs that your kefir is not ok.

  • Unusual smell: While kefir has a naturally tangy and slightly sour smell, a strong, rotten, or “off” odor can indicate contamination or spoilage.

  • Mold growth: Visible mold on the surface (often green, blue, or black spots) is a clear indication that something has gone wrong. It’s unsafe to consume kefir if mold is present.

  • Separation and texture: While some separation of curds (solids) and whey (liquid) is normal, an excessive or overly lumpy, slimy texture could mean the kefir has over-fermented or become contaminated.

  • Discoloration: Kefir should be creamy white or slightly yellow. If the color appears brown, pink, or shows streaks, it’s a bad sign.

  • Excessive fizz: While kefir can sometimes be slightly fizzy due to fermentation, an overly carbonated or foamy texture may indicate fermentation issues or the presence of harmful bacteria.

  • Off taste: Kefir should taste tart and tangy, sometimes with a mild yeasty flavor. A bitter, overly sour, or strange aftertaste can be a sign of spoilage or improper fermentation.

  • Growth issues with kefir grains: If the kefir grains stop growing or appear unhealthy (discolored, slimy, or shrinking), it may indicate contamination or poor fermentation conditions.

How much kefir should you drink?

Generally, kefir is safe to drink and low in calories. So, there is no clear limit to the amount you can have in a day. However, please be aware of the fact that it may contain trace amounts of alcohol that can influence your alertness. Also, if you feel any discomfort (such as bloating), please reduce your intake, at least temporary. Other than that: enjoy your kefir!

Conclusion

So, there are many reasons to drink kefir. Foremost it being very tasty! While milk kefir can certainly have potential benefits, it is important to never use it as a sole remedy for any ailments, and always consult your doctor.

Want to read more?

Want to check out the actual scientific papers that this blog is based on? Check them out here!

About Meneer Wateetons

Meneer Wateetons is a renowned Dutch foodwriter, teacher, fermentation specialist, sausage maker and the owner of startercultures.eu. He has written 9 books on culinary topics such as fermentation, alcohol making, sausages and charcuterie making and deep frying. He has taught many hobbyists, chefs and food professionals about these topics. He loves kombucha!

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