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7 Kefir Benefits Examined (Are They True or Not?)

Researched and Written by:
Jenna Swift, APD Dietitian Jenna Swift, APD Dietitian Richelle Godwin, RDN Richelle Godwin, RDN

In this article we’re going to look at the 7 major health claims of kefir…and which are true and which are not…in order to find out whether it really is a superfood or just another overhyped fad. And of course if you’re ALREADY getting yogurt and other fermented foods and drinks in your diet we’ll look at whether it is worth making room in your fridge for kefir.

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Table of Contents

    Health Claim #1: Kefir Improves Gut Health

    The number one reason most people drink kefir is to support their gut health.  And if that’s why you love it too, then you’re in luck.  

    You see, it turns out this health claim is true…and kefir is fantastic for gut health.  The main reason it helps so much is because of the good bacteria, also known as probiotics, that you’ll find in every glass.

    In fact, when it comes to probiotics, kefir is even better than the most popular cultured dairy product on the planet…which is yogurt. Here’s a clip from our Kefir vs Yogurt video explaining why.

    Pretty cool, right?!  And given that many gastrointestinal problems are associated with Low levels of good bacteria in the gut and Poor diversity of gut bacteria, kefir’s ability to deliver billions & billions of good bacteria to our microbiome is something to get excited about.  

    Indeed, based on this benefit alone, I along with the rest of the research team here at Essential Stacks, will raise a glass to the champagne of dairy. 

    Health Claim #2: Kefir Lowers Cholesterol

    High cholesterol levels have been linked to some serious health issues over the years.  In particular, some aspects of LDL cholesterol (which is the bad type of cholesterol) and triglyceride levels (which is a type of fatty substance that circulates in your blood)…have both been associated with an increased risk of heart disease.

    Unsurprisingly, doctors like to prescribe statin drugs to manage cholesterol levels.  In fact, right now over 35 million Americans take statin drugs to manage their cholesterol levels day to day.  

    So the health claim that kefir may lower cholesterol is worth investigating.  Let’s take a look at what we found.

    Overall, the results we’ve seen in human studies are a mixed bag. While some studies have shown promise, others did not find any cholesterol-lowering benefits from consuming kefir. 

    In fact, in one study focused on diabetics, the subjects were drinking a whopping 20 fluid ounces or 600 mils of kefir every single day, for over 8 weeks.  That’s a whole lotta kefir!  And yet it couldn’t move the dial on total cholesterol, LDL or other cholesterol markers. 

    There is some good news though. 

    We came across a giant meta analysis done of 39 studies involving a total of over 2,200 participants who consumed fermented dairy products.  And the researchers concluded that probiotic fermented milk products like kefir, may help reduce serum total cholesterol and LDL levels.

    The catch with these results - the benefit was greater for men than women, and was only noticed after 8 weeks of continual consumption.

    Now, our research team found another promising study that showed kefir reduced LDL cholesterol (the bad type) and raised HDL cholesterol (the good type). But the catch with this study…it was done in mice with high cholesterol and used a probiotic strain isolated from Tibetan kefir grains.

    Now, it’s nice to know that kefir can help Tibet...enjoy more cheese, but hopefully in the future, there will be more conclusive research that shows kefir can help lower cholesterol in people as well!

    So for now, when it comes to lowering cholesterol, the jury is still out.

    Health Claim #3: Kefir Reduces Blood Sugar Levels

    Blood sugar levels are on the rise worldwide, along with diabetes and pre-diabetes. In fact, roughly 1 in 10 Americans have been diagnosed with diabetes.

    That’s approximately 37 million people!  And the vast majority of them…like 90-95%...have type 2 diabetes.

    That means they struggle with insulin resistance and blood sugar transportation.  
    And it is obviously a big problem, because this is associated with a high risk of heart disease and other chronic conditions.

    So the health claim that kefir may be able to help reduce blood sugar levels is fascinating.  But is this claim true? 

    Well, our research team was very excited by the first study we came across. It showed that after 8 weeks of drinking kefir every day, the participants’ blood sugar levels dropped by 16% on average. That’s pretty impressive, especially since the people involved had type 2 diabetes.  

    Unfortunately, we couldn’t find any other research that mirrored these results.  So for now, this benefit remains a maybe at best, and we will need more research to support this claim.

    Health Claim #4: Kefir Improves Bone Health & Reduce the Risk of Osteoporosis

    If you or your parents have experienced the impact of poor bone health or osteoporosis itself, then the claim that kefir may strengthen bones and reduce the risk of osteoporosis is worth looking at.

    So the first thing we do know is that milk kefir, is obviously going to contain a good amount of calcium…usually around 10% more than whole milk.  And calcium is of course, an important building block of strong bones. 

    Given many Americans don’t get enough calcium through their diet or in fact deplete their calcium stores due to poor diet, kefir can be helpful.

    But is that the whole story?  

    Well, it turns out that in order to increase absorption of calcium and thus actually strengthen the bones, your body also needs vitamin K2.  In fact, studies show that consuming enough Vitamin K2 may cut down your risk of osteoporosis by as much as 81%. 

    Unfortunately nearly all adults over age 40 may be deficient in vitamin K2, with some studies suggesting up to 97% of older people are deficient in it.

    And so this is where kefir which is an excellent source of vitamin K2 and much higher in K2 than whole milk, may really help.  Indeed, Vitamin K2 may be the X-factor nutrient in kefir when it comes to bone health. 

    Best of all, the friendly bacteria in kefir may actually enhance the nutrient content of certain vitamins such as vitamin K. 

    So given kefir is packed with calcium, and even more importantly vitamin K2, there is good evidence to suggest it will support bone health. 

    Health Claim #5: Lowers Blood Pressure

    High blood pressure is a silent killer.  Without warning, chronic elevated blood pressure can lead to a debilitating or even Fatal stroke or heart attack.  In fact, it is one of the Leading causes of premature death worldwide.

    So can kefir reduce blood pressure? 

    Well, just before we jump into this, let’s be clear.  Certain lifestyle factors like alcohol and smoking will cause high blood pressure regardless of how much fermented milk one drinks. So in other words, we’re not expecting research studies to show us that kefir can help the Keith Richards of the world miraculously have blood pressure within a normal range. 

    But is there any merit to the health claim for the rest of us? 

    Well, from our research we didn’t find any overwhelming evidence to support this health claim.  But we did find reason to be cautiously optimistic. 

    You see, one small study (and by small, I mean microscopic) compared the blood pressure levels of 12 people who drank about 6 ounces of kefir every day for 3 months, with 10 people who were given regular milk.

    The result was that the kefir-drinking group experienced a significant drop in both systolic blood pressure and diastolic blood pressure.

    The regular milk drinkers only experienced a slight drop in systolic blood pressure. With all of that said, the overall impression our research team formed, is that while these results are promising, much more research is needed. 

    Health Claim #6: Improves Lactose Tolerance 

    Lactose intolerance is a big deal in today’s world.  In fact, did you know that experts estimate nearly 70% of us struggle to digest the lactose milk sugar found in dairy products?  

    The main reason for this…many of us don’t have enough enzymes to digest lactose.  And in case you want to know the name of that enzyme…it’s called Lactase. 

    So the idea that kefir can help improve lactose tolerance is really interesting.  And even moreso, when we take a moment to realize that traditional kefir is actually made from Cow’s, sheep or goat’s milk…which as you know, all contain lactose!

    How does that make sense? 

    Well, there are claims that kefir is a actually a Cultured dairy paradox!  And, what I mean by that, is even though kefir is typically made using milk which contains lactose, it also contains friendly lactic acid bacteria, which love to gobble up lactose and break it down for us into lactic acid.  That means kefir has less lactose in it, than the milk it was made from.   

    Now what all of this means to us, is that Kefir is easier to tolerate than normal milk.  But…and this is a big but…it does NOT mean that kefir is going to improve your ability to digest lactose in other foods and drinks you eat throughout the day.

    Health Claim #7: Kefir Is Anti-Bacterial

    Throw away your anti-bacterial hand soap and instead, wash your hands with kefir! …Just kidding. Don’t try that at home. 

    But there are claims online that kefir, or at least the probiotics in kefir, have potent antibacterial properties.  So is this true?

    Well, in one study our research team found, salmonella was placed in a bottle of kefir.  And just before we go on, in case you don’t know, salmonella is the bad bacteria that is responsible for about 1.35 million cases of food poisoning a year in the USA alone. 

    Now, guess what happened 24 hours later when the researchers checked the bottle of kefir? 

    To the researchers' astonishment, there were no traces of salmonella left!  Like David Copperfield making the Statue of Liberty disappear, kefir pulled off a remarkable vanishing act. 

    And while this all sounds very promising, it should be noted that in these studies, the probiotics in Kefir did not have any impact on other pathogens such as e coli. 
    So while kefir does have some anti bacterial properties, it’s hard to conclude just how useful it is as a tool in the fight against bad bacteria.

    Our Conclusion

    As we’ve seen there are a lot of different health claims being tossed around by kefir lovers.  But the reality is that Most of them Need more research…and in particular, they need Better quality studies both in terms of study design & participant count.  

    The good news though, is that for all of us drinking kefir for the benefit of gut health…the verdict is clear…kefirbillions and billions of good bacteria, and this is extremely helpful for Supporting our microbiomes.  And given that low levels of good bacteria in the gut are associated with many gastrointestinal issues, this is a huge win!

    So for that reason alone, kefir is a fermented food worth stocking in your fridge.


    Evidence Based

    An evidence hierarchy is followed to ensure conclusions are formed off of the most up-to-date and well-designed studies available. We aim to reference studies conducted within the past five years when possible.

    • Systematic review or meta-analysis of randomized controlled trials
    • Randomized controlled trials
    • Controlled trials without randomization
    • Case-control (retrospective) and cohort (prospective) studies
    • A systematic review of descriptive, qualitative, or mixed-method studies
    • A single descriptive, qualitative, or mixed-method study
    • Studies without controls, case reports, and case series
    • Animal research
    • In vitro research

    1 comment

    • Will kefir interact with warfarin.

      Billy White

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