Seven Dangerous Side Effects of Kefir

Kefir is a popular fermented drink made of milk and kefir grains that contains probiotics (gut-healthy bacteria). While consuming kefir may offer many health benefits, there are also some potential downsides to consider.

1. May Cause Digestive Issues

While kefir is generally known to improve digestion, it can trigger gastrointestinal problems in some people. You are likely to have stomach troubles, if at all, by drinking too much of the beverage.

, such as:

• Abdominal discomfort or cramps
• Bloating
• Diarrhea
• Gas

It’s worth noting that kefir contains a small amount of lactose, which may cause stomach problems in those who are lactose intolerant. However, lactose-free kefir alternatives are available.

2. May Increase Blood Sugar

If kefir is plain and unsweetened, it might actually help in people with type 2 diabetes. However, some kefir products contain a lot of added sugar, which can increase blood sugar levels. This spike can occur when drinking any sweetened beverage. It’s important to read the product label to know how much added sugar it contains, especially if you have diabetes.

3. May Interact With Certain Medications

Kefir and other (foods that stimulate the growth of beneficial microorganisms in the digestive tract) can affect how some medications work or are absorbed in your body. Some research suggests probiotics may interact with:

• Antibiotics
• Antifungal drugs
• Certain antidepressants
• Anti-cancer drugs
• Blood thinners or heart medicines
• Cholesterol-lowering drugs

Talk to your healthcare provider if you’re interested in drinking kefir but take medications for a health condition.

4. May Increase Infection Risk in Certain Populations

Some studies suggest a link between probiotic consumption and an increased risk of infections. One report linked probiotics to rare , a life-threatening response by the body to an infection. However, other research has found that probiotics may actually help fight certain infections. You may want to avoid kefir if you have a . This includes people who have cancer, human immunodeficiency virus (HIV), an autoimmune disease, or have received an organ transplant.

5. May Contain Alcohol

Kefir products can contain trace amounts of alcohol. That’s because the yeast in the grains produces a small amount of alcohol during fermentation, usually less than 2%. By comparison, wine typically contains 12% to 14% alcohol. While the content is low, you may want to avoid kefir if you are sensitive to alcohol.

6. May Trigger an Allergic Response

Kefir contains milk. People who are allergic to dairy could have a severe allergic response if they drink the beverage. If you have a dairy allergy, you still can take advantage of nondairy types of kefir.

7. May Contain Raw Milk

Some people make or purchase kefir with raw milk that has not been pasteurized. The Food and Drug Administration (FDA) warns that unpasteurized milk can harbor harmful germs and cause food poisoning. Symptoms can include:

• Abdominal pain
• Diarrhea
• Flu-like symptoms, such as fever, body aches, and headache
• Vomiting

Make sure you read the product label and look for the word “pasteurized.”

How to Drink Kefir to Reduce Side Effects

Here are some ways you can consume kefir safely:

• Don’t drink too much: Consuming too much kefir can lead to side effects. While no official guidelines exist, experts recommend drinking no more than 1 to 3 cups of kefir daily. However, you may have to start out drinking less than this to allow your digestive system to adjust.
• Take it with food: Drinking kefir with food may help reduce your chances of experiencing digestive issues.
• Don’t drink it at night: Avoid drinking kefir right before bed if it disrupts your sleep.
• Check the labels: Make sure the product is pasteurized. Also, check the sugar content and look for any possible allergens.
• Store it properly: Keep kefir refrigerated to prevent over-fermentation.
• Talk to your healthcare provider. If you have a medical condition or take medications, be sure to discuss the use of kefir with a medical professional before trying it.

Other Ways to Boost Gut Health

If you cannot tolerate kefir, there are alternative ways to boost your gut health, such as consuming:

• Buttermilk
• Kombucha
• Miso
• Nondairy kefir
• (capsules, powders, or chews)
• Sauerkraut
• Tempeh
• Yogurt