Dr. Thomas Dwan - Is It Bad For You? Approved by Dr. Thomas Dwan

Is Kefir Bad For You?



Short answer

Kefir is generally good for you, offering probiotics that support gut health, aid digestion, boost immunity, and may have anticarcinogenic properties. For those with lactose intolerance, kefir is often more tolerable than regular dairy due to its lower lactose content. However, it's important to consider potential downsides like added sugars in flavored varieties, alcohol and yeast by-products, and histamine sensitivity reactions. Moderation is key, and consulting with a healthcare provider is advised, especially for individuals with health concerns or dietary restrictions.



Recommended Alternative

Long answer

Understanding Probiotics: The Benefits of Kefir

Probiotics are live microorganisms, often called "friendly bacteria," that confer health benefits when consumed in adequate amounts. Kefir, a fermented milk drink with a tart taste, is teeming with these beneficial probiotics. Let's delve into how these microorganisms in kefir can be advantageous to our health.

1. Gut Health and Digestion: Kefir contains a diverse community of bacteria and yeast, which helps balance the gut microbiome. This can improve digestive health by enhancing bowel movements and reducing bloating. Particularly, the probiotic Lactobacillus kefiri, found in kefir, has been shown to inhibit the growth of some harmful bacteria like Salmonella and E. coli.

2. Immune Support: A healthy gut is critical for a robust immune system, as a large portion of the immune system is actually housed in the gut. The probiotics in kefir may help modulate the immune response, potentially reducing the risk of infections and inflammation.

3. Lactose Digestion: The fermentation process reduces the lactose content of kefir, making it easier to digest for people with lactose intolerance. The enzymes produced by the probiotics, such as lactase, further assist in breaking down lactose, providing a dairy option for those who usually experience discomfort after consuming traditional dairy products.

4. Nutrient Absorption: Consuming kefir can enhance the absorption of nutrients from your diet. Probiotics help in breaking down and assimilating nutrients that may be otherwise difficult for the body to access, such as B vitamins, calcium, and magnesium.

5. Potential Anticarcinogenic Properties: Some research suggests that the compounds produced during the fermentation of kefir can have anticarcinogenic properties. By binding to mutagens, these probiotics could reduce the risk of cancer development.

6. Mental Health and Probiotics: The connection between the gut and the brain, known as the 'gut-brain axis,' has been drawing significant attention. There is emerging evidence to suggest that the probiotics in kefir could influence brain health, potentially affecting mood and cognitive function.

While there are many potential benefits associated with the probiotics found in kefir, it's important to consider personal health conditions and dietary restrictions before introducing it into your diet. As always, it's best to consult with a healthcare provider, particularly if you have an underlying health issue or are on medication that could interact with these probiotics.

Lactose Content in Kefir for the Lactose Intolerant

Understanding the nuances of how kefir interacts with lactose intolerance is essential for making an informed decision about its consumption. Kefir, a fermented milk drink, is often touted for its probiotic benefits. However, for those with lactose intolerance, the primary concern revolves around its lactose content.

First and foremost, it's important to note that during the fermentation process, the beneficial bacteria and yeasts in kefir consume most of the lactose (the sugar found in milk) and convert it into lactic acid and other byproducts. This process inherently reduces the lactose content of kefir. Consequently, many individuals who are lactose intolerant may find they can tolerate kefir better than other dairy products.

A study published in the Journal of the American Dietetic Association found that lactose-intolerant individuals experienced fewer adverse symptoms when consuming kefir compared to regular milk. However, tolerance levels can vary greatly between individuals.

It is crucial for those with lactose intolerance to consider the following points:

  • Type of Kefir: There are varying types of kefir, including full-fat, low-fat, and non-dairy versions. Full-fat and low-fat kefir made from cow's milk will contain some level of lactose, whereas non-dairy alternatives, typically made from coconut milk or rice milk, will be lactose-free.
  • Fermentation Duration: Longer fermentation times can result in a kefir with even less lactose, as the bacteria and yeasts have more time to ferment the sugars in milk. For those sensitive to lactose, seeking out kefir that boasts a longer fermentation period could be beneficial.
  • Probiotic Strains: Some of the strains of probiotics in kefir, such as Lactobacillus and Bifidobacterium, have been shown to help break down lactose, potentially assisting those with lactose intolerance in digesting the product more easily.
  • Individual Variability: Tolerance to lactose is highly individual. While some may consume kefir without any issues, others might experience discomfort. Starting with a small amount and gradually increasing the serving size can help assess personal tolerance.
  • Reading Labels: Not all kefir is created equal, and manufacturers may add lactose or milk solids back into the product. It is always advised to read labels carefully to identify any added lactose.

Considering the factors above, lactose-intolerant individuals should cautiously approach the inclusion of kefir in their diet. The best practice is to consult with a healthcare provider or a dietitian before trying kefir, particularly for those with severe lactose intolerance. It's also worth experimenting with lactose-free kefir or kefir with live and active cultures to potentially reap the benefits of probiotics without the discomfort of lactose-related symptoms.

In summary, kefir may be a suitable option for some people with lactose intolerance due to its reduced lactose content and probiotic properties. Monitoring individual reactions and making thoughtful choices about the type and quantity of kefir consumed are key steps in incorporating this fermented drink into a lactose-intolerant friendly diet.

Alcohol and Yeast: Fermentation By-Products in Kefir

Kefir, a fermented milk beverage filled with probiotics, is made by inoculating milk with kefir grains - a symbiotic matrix of bacteria and yeasts. During fermentation, these microorganisms consume the lactose (sugar) present in the milk, creating a variety of compounds that contribute to kefir's unique taste, texture, and health benefits. However, two by-products of this fermentation process are alcohol and yeast cultures, which may prompt health considerations for certain individuals.

First, let's tackle the issue of alcohol in kefir. Owing to the fermentation, kefir typically contains a small percentage of alcohol, usually less than 2%. This is a natural outcome of yeast metabolism, where sugars are converted into alcohol and carbon dioxide. It is worth noting that the exact alcohol content can vary depending on the fermentation time, temperature, and specific kefir cultures used. The alcohol level in kefir is generally too low to induce intoxication, but its presence can be a concern for those avoiding alcohol for health, dietary, or religious reasons.

Although the alcohol content is minimal, studies have shown that even low levels can impact certain populations negatively. For example, individuals with alcohol intolerance or those suffering from liver diseases should exercise caution. A study published in the Journal of Medicinal Food suggests that probiotic-rich foods like kefir can benefit liver function, but the presence of alcohol, albeit small, may warrant moderation in at-risk groups.

Besides alcohol, the presence of active yeasts in kefir is another topic of interest. Those with yeast sensitivities or certain immune disorders might find themselves reacting to these microbes. Yeast cultures in kefir are viable and active, aiding in gut health for most, but for someone with a condition like Candida overgrowth, the added yeast could exacerbate the problem. However, it's important to differentiate between the benign yeasts in kefir and the pathogenic yeasts associated with infections. The beneficial yeasts in kefir, such as Saccharomyces unisporus and Saccharomyces turicensis, have been shown to possess probiotic properties themselves.

Lastly, it's worth mentioning that the fermentation process and subsequent refrigeration significantly slow down the activity of yeasts, stabilizing the product. This ultimately means that off-the-shelf kefir has a relatively stable yeast content and should not present a problem for most people. For those making kefir at home, controlling fermentation time is key in managing both alcohol and yeast levels in the final product.

In closing this section, the fermentation by-products in kefir do necessitate consideration, but the existing evidence points to a largely beneficial profile for most individuals. As always, moderation is essential, and for those with specific health concerns, consulting a healthcare professional is advisable before incorporating kefir into one's diet.

The Sugar Content in Flavored Kefir Varieties

Kefir, a fermented milk drink similar to a thin yogurt, is touted for its probiotic benefits, which can aid in digestion and improve gut health. While plain kefir can be a nutritious addition to the diet, flavored kefir varieties often contain added sugars that can detract from their health benefits. The sugar content in these flavored kefirs can vary widely, making it crucial for consumers to be mindful of the labels when selecting a product.

Many commercial kefir products come in fruit-flavored varieties, such as strawberry, blueberry, and pomegranate. These flavors are popular for their taste, but they can disguise a high sugar content that is not present in the plain versions. Here's a breakdown of what to look for and consider:

  • Added Sugars: Some companies add sugar to improve the taste of kefir, particularly to offset the naturally sour flavor of the fermented milk. The grams of added sugars can sometimes equal or surpass those found in sodas and desserts.
  • Nutritional Labels: Always check the nutritional labels for the amount of sugars, which includes naturally occurring lactose and any added sugars. Keep an eye out for words like cane sugar, fructose, sucrose, or any syrup, as these indicate the presence of added sugars.
  • Recommended Limits: The American Heart Association suggests that women should consume no more than 6 teaspoons (25 grams) of added sugar per day, and men should limit their intake to about 9 teaspoons (38 grams). A single serving of flavored kefir can, in some cases, approach or exceed these limits.
  • Not All Sugars Are Equal: It's important to note that the lactose found in kefir is a natural sugar and differs from added sugars; the fermentation process even breaks down much of the lactose, making it easier to digest, especially for those who are lactose intolerant.

For health-conscious consumers, it might be worth considering the sugar content in flavored kefir as an occasional treat rather than a daily staple. Opting for plain kefir and adding fresh fruit at home can deliver a similar taste with less sugar.

One study published in the Journal of the Academy of Nutrition and Dietetics suggests that consuming high levels of added sugars can lead to an increase in cardiovascular risk factors, highlighting the importance of monitoring sugar intake from all sources, including seemingly healthy foods like kefir.

Flavored kefir can be a deceiving source of excess sugars in one's diet. By being vigilant with label reading and making informed choices, individuals can enjoy the probiotic benefits of kefir without compromising their sugar intake.

Kefir and Histamine Sensitivity: Potential Allergic Reactions

Kefir, a fermented milk drink similar to yogurt, is celebrated for its probiotic content and various health benefits. It’s made by adding kefir grains to milk, which leads to fermentation by bacteria and yeast. While many praise its probiotic prowess, for some individuals, kefir may provoke histamine sensitivity-related allergic reactions. This sub-section takes a closer look at what this means for those sensitive to histamines or prone to allergies.

Histamine is a chemical involved in your body's immune response. It's also found in various foods, especially those that are fermented, such as kefir. Individuals with histamine intolerance may struggle to break down this compound due to low levels of the enzyme diamine oxidase (DAO), which can lead to a range of symptoms upon consumption of histamine-rich foods.

  • Symptoms of Histamine Intolerance: Headaches, hives, fatigue, nasal congestion, nausea, and in more severe cases, abdominal cramping, diarrhea, and even difficulty breathing.
  • Increased Histamine Levels: Fermented foods like kefir can increase histamine levels in the body, potentially exacerbating these symptoms.

It's important to consider that not everyone experiences these symptoms, and many can enjoy kefir without any adverse effects. However, for individuals with histamine sensitivity or certain allergic conditions, kefir could be problematic. This is also the case for people with Mast Cell Activation Syndrome (MCAS), where mast cells erroneously release too much histamine.

To better understand the relationship between kefir consumption and histamine sensitivity, studies have looked into the types of bacteria present in kefir. Some strains of bacteria can produce histamine, while others can degrade it. A study found in the National Institutes of Health database highlights certain lactic acid bacteria, commonly found in kefir, that possess histamine-degrading abilities. However, the histamine content in kefir can vary widely depending on factors such as fermentation time and temperature.

For those concerned about potential allergic reactions to kefir due to histamine sensitivity, the following steps may help mitigate the risks:

  • Start With Small Amounts: Introduce kefir gradually to your diet to monitor the body’s reaction.
  • Choose Non-Dairy Kefir: Options like water kefir could be less likely to provoke a histamine response.
  • Consult With a Healthcare Provider: Before including fermentable foods in your diet, a health professional can provide personalized advice.
  • Proper Storage and Handling: Fresh kefir, stored correctly and consumed promptly, may have lower levels of histamine than those stored for extended periods at inappropriate temperatures.

In summary, kefir may pose certain risks for individuals with histamine sensitivity or particular allergic conditions. Recognizing the symptoms of histamine intolerance and understanding the variance in individual reactions are crucial for safely including kefir in one's diet. As with any dietary change, especially for those with known sensitivities or allergies, it is advised to consult a healthcare professional for advice tailored to specific health needs.

Balancing Kefir in Your Diet: When Too Much of a Good Thing May Be Harmful

While kefir is praised for its probiotics and health benefits, moderation is key, as with any food or supplement. Overconsumption of kefir can potentially lead to adverse effects. It's important to balance your intake of kefir to fit within a diverse and balanced diet. Below are some considerations and guidelines for incorporating kefir into your diet without overdoing it.

Lactose Intolerance Concerns:
Kefir, albeit lower in lactose compared to regular milk, still contains this sugar, which can be problematic for those with lactose intolerance. Symptoms such as bloating, gas, and diarrhea can occur if kefir is consumed in large quantities by individuals with this condition.

High Calorie and Fat Content:
Some kefir varieties, especially those made from full-fat milk, can be high in calories and saturated fats. Drinking large amounts of kefir, especially when consumed in addition to your normal diet without compensatory reduction of other caloric contributions, may contribute to weight gain and associated health issues.

Probiotic Overload:
Although probiotics are beneficial, there is a limit to how much our gut microbiome needs. An excess of probiotics from too much kefir can lead to an imbalance, causing issues such as bloating, gas, and even infection in individuals with weakened immune systems.

Protein Excess:
Kefir is rich in protein, which is vital for many bodily functions. However, excessive protein intake can strain the kidneys, particularly in individuals with pre-existing kidney conditions.

Calcium Overload:
High intake of calcium-rich foods like kefir can lead to hypercalcemia, a condition where calcium levels in the blood become too high. This can cause various health problems, including kidney stones and cardiovascular disease.

When integrating kefir into your diet, consider the following to ensure you reap the benefits without the downsides:

  • Start with small portions to see how your body reacts, particularly if you have a sensitive digestive system or lactose intolerance.
  • Leverage low-fat or non-fat kefir options to reduce caloric and fat intake if you're watching your weight or fat consumption.
  • Mix kefir with other foods like fruits, nuts, or whole grains to create balanced meals or snacks, rather than drinking it in isolation.
  • Monitor your overall daily protein intake, ensuring that kefir does not push you over recommended amounts.
  • Be cautious with kefir consumption if you have a compromised immune system, and consult with a healthcare provider.
  • Balance your intake of other calcium-rich foods with kefir to avoid excessive calcium intake.

In conclusion, while kefir certainly holds a spot in a healthy diet, it's important to consume it in a way that aligns with your individual dietary needs and health considerations. If uncertain about the right balance, consulting with a dietitian can provide personalized guidance based on your health goals and dietary restrictions.

Frequently asked questions

While kefir is usually beneficial, some individuals may experience side effects like bloating and gas, particularly when introducing it into their diet or consuming it in large quantities due to an adjustment in gut bacteria. People with compromised immune systems should exercise caution due to the active bacterial cultures. Always start with small amounts to monitor your body's reaction.

Kefir is known for its lower lactose content due to fermentation, which could help those with lactose intolerance manage their symptoms. The probiotics in kefir produce lactase, an enzyme that breaks down lactose, potentially allowing those with intolerance to enjoy kefir without discomfort. It's recommended to start with small amounts to assess tolerance.

Kefir can be a nutritious choice for pregnant or breastfeeding women, offering probiotics and nutrients essential for health. However, it's important to choose pasteurized kefir to avoid potential harmful bacteria. As with any dietary changes during pregnancy or breastfeeding, consulting with a healthcare provider is advised.

Traditional kefir is made from dairy milk, but non-dairy versions of kefir, such as coconut milk kefir or water kefir, are suitable for vegetarians and vegans. These options maintain the probiotic benefits without utilizing animal products, making them an excellent alternative for those following plant-based diets.

Ask a question about Kefir and our team will publish the answer as soon as possible.

Possible short-term side effects

  • bloating
  • gas
  • diarrhea
  • headaches
  • hives
  • fatigue
  • nasal congestion
  • nausea
  • abdominal cramps

Possible long-term side effects

  • weight gain
  • probiotic imbalance
  • kidney strain
  • hypercalcemia
  • increased cardiovascular risk factors

Ingredients to be aware of

  • alcohol
  • yeasts
  • lactose
  • added sugars
  • histamines


  • enhanced digestion
  • immune system support
  • lactose digestion aid
  • improved nutrient absorption
  • potential anticarcinogenic effects
  • mood and cognitive function

Healthier alternatives

  • non-dairy kefir
  • low-fat kefir
  • kefir with live and active cultures
  • plain kefir with fresh fruit

Our Wellness Pick (what is this?)

Lifeway Probiotic Kefir

  • Boosts digestive health
  • Low-fat formulation
  • Rich in probiotics
  • Delicious vanilla flavor
  • 32 oz quantity
Learn More!

Thank you for your feedback!

Written by Diane Saleem
Published on: 11-29-2023
Last updated: 12-15-2023

Thank you for your feedback!

Written by Diane Saleem
Published on: 11-29-2023
Last updated: 12-15-2023

Random Page

Check These Out!