Is kefir healthy? Separating fact from fiction

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.

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.

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.

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.

Milk kefir: nutritional, microbiological and health benefits – Rosa et al (2017)

The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir – Bourrie et al (2016)

The effects of kefir consumption on human health: a systematic review of randomized controlled trials – Kairey et al (2022)