Is Kefir Good for You?

Seeing kefir in the dairy section of your grocery store and want to know more? Kefir (pronounced “kee-feer”) is a fermented milk drink that people have been sipping for thousands of years. And according to both ancient wisdom and modern research, yes — kefir is good for you.

Registered dietitian Amber Sommer, RD, LD, tells us what we need to know about this yogurt-like beverage.

Is kefir healthy?

Kefir’s nutritional benefits vary depending on the type of milk it’s made with and the exact fermenting process used.

“In general, though, it’s considered healthy,” Sommer reinforces. “And it’s better for you than yogurt because it contains more strains of probiotics and beneficial yeast.”

Let’s back up: Kefir is made by adding something called “kefir grains” to cow, goat or sheep milk. Think of kefir grains like a kind of sourdough starter, full of yeast and good bacteria. These microorganisms convert lactose (milk sugar) into lactic acid, which gives kefir a sour taste.

It’s also loaded with vitamins, minerals and nutrients. One cup of low-fat, plain kefir has about:

• 11.6 grams of carbohydrates
• 2.5 grams of fat
• 11.2 grams of sugar
• 9 grams of protein

It’s also rich in nutrients, including:

• 29.2 milligrams of calcium
• 399 milligrams of phosphorus
• .7 micrograms of vitamin B12
• 0.3 milligrams of riboflavin
• 29.2 milligrams of magnesium
• 2.4 micrograms of vitamin D

“Studies are ongoing, but it seems there are many benefits of kefir,” Sommer says. “Like other foods that contain probiotics (good bacteria) and postbiotics (bacteria byproducts), kefir boosts gut health and provides several other health benefits.”

Let’s take a closer look at kefir’s nutrients, probiotics and benefits.

1. Promotes gut health

Kefir contains approximately 12 active probiotic strains, which can help keep harmful bacteria in check and support your overall gut health.

“Your digestive tract is home to an entire world of microorganisms (known as your gut microbiome), like bacteria, fungi and viruses,” Sommer explains. “When you eat probiotic- and postbiotic-rich foods like kefir, it adds more good bacteria to your gut.”

That’s important because too much “bad” gut bacteria can cause uncomfortable digestive symptoms, like:

• Abdominal pain
• Bloating
• Constipation
• Diarrhea
• Gas

But foods like kefir can help. One study suggests that regularly consuming kefir positively shifts the balance of organisms in the microbiome. Another study found that kefir relieves chronic constipation.

2. Supports bone health

A glass of kefir contains the nutrients you need to build and repair bones, including:

• Calcium: This essential mineral makes bones hard. As our bodies can’t produce it, it’s essential to get enough in your diet.
• Vitamin D: Your body can’t absorb calcium without vitamin D, making it especially crucial for bone health.
• Phosphorus: This mineral, which is abundant in most people’s diets, works alongside calcium to build bones.
• Magnesium: A key component in bone structure, this essential mineral helps make bones stronger.
• Vitamin K: This vitamin, which is found in whole-milk kefir, is involved with multiple bone processes.

“Having strong bones is essential for staying active, especially as you age and start to lose bone mass,” Sommer notes. “Getting enough calcium is one of the best ways to keep your bones strong and prevent osteoporosis.”

3. Has germ-fighting properties

Talk about a gut superhero: Kefir helps fight off illness-causing germs like E. coli and Salmonella. And in lab studies, kefir was just as effective at combating harmful bacteria as antibiotics.

“The good bacteria in kefir compete with harmful organisms for resources in your gut,” Sommer says. “And they also release byproducts that are toxic to the bad bacteria and yeast.”

And there’s more: In addition to battling bad bacteria in your gut, kefir helps protect your teeth against bacteria that cause cavities. When a dental study compared drinking kefir with a daily fluoride rinse, it found them to be equally effective in reducing cavity risk.

(P.S.: None of this means that you can stop brushing your teeth or opt for kefir over medicine when you’re sick. It just means that kefir may be a good complement to other germ-fighting habits.)

4. Contributes to healthy muscles

While kefir doesn’t have as much protein as Greek yogurt, it does have more than an egg, which places it solidly in the “good source of protein” category.

Why does that matter? Because protein is essential for building, maintaining and repairing muscles, which, in turn, fuels your metabolism. In other words, protein is pretty darn important to your body.

And when it comes to muscle health, kefir brings more to the table than just a hefty dose of protein.

“It also has magnesium, which is important for muscle movement, and phosphorus, which plays a role in the growth and repair of tissue,” Sommer points out.

5. Helps manage blood sugar

If you have Type 2 diabetes, your body can’t effectively process blood sugar. But a study of people with Type 2 diabetes found that drinking 20 ounces of kefir a day helped keep blood sugar levels in check.

But it’s important to note that flavored kefir can be high in sugar (which cancels out this particular benefit). So, pay attention to the sugar content in whatever type of kefir you choose, especially if you’re drinking it for blood sugar support.

6. May help ease stress

Could drinking kefir help you better face stressful situations? A lab study on kefir consumption says so. Research found that the probiotic drink changed the makeup of gut bacteria, shifting it toward bacteria that produce gamma-aminobutyric acid (GABA).

“This amino acid has a calming effect on your brain, which helps you relax,” Sommer explains. “Other substances in kefir — like B vitamins, magnesium and tryptophan — are also known to help ease tension by creating and regulating brain chemicals that stabilize your mood.”

7. Low in lactose

Kefir is so low in lactose (milk sugar) that even people with lactose intolerance can often drink it without experiencing the usual tummy troubles that dairy products can cause.

“As kefir ferments, the yeasts and bacteria in it break down milk sugar and ultimately turn it into an extremely low-lactose product,” Sommer further explains.

She notes that, although fully dairy-free options exist, they don’t have the same nutritional profile as traditional kefir.

Possible downsides of kefir

When you first start eating foods that are high in probiotics, it’s common to experience an adjustment period that includes symptoms like gas and bloating.

“Add kefir slowly as your body adjusts to the addition of probiotics,” Sommer advises.

And while kefir can be a delicious way to boost your overall health, she again urges you to pay attention to the sugar content in flavored varieties.

“Too much sugar takes away from the health benefits of kefir,” she cautions. “Pick options that are lower in sugar, or just stick to plain kefir.”

How to incorporate kefir into your diet

It’s easy to start adding kefir to your regular rotation.

“If you usually eat plain yogurt, just start swapping it out for kefir sometimes instead,” Sommer suggests.

That said, some people don’t love kefir’s sour taste on its own. If you’d rather cover up that flavor a little, you can:

• Blend kefir into smoothies.
• Pour it over cereal instead of milk.
• Add a small amount to overnight oats.
• Swap kefir in for milk in recipes for cold soups and salad dressings.

Some people use kefir in place of milk or heavy cream in their baked goods, too. But keep in mind that heating kefir kills the “good bacteria” that make it so gut-healthy in the first place. It certainly won’t make kefir bad for you. But if you want to reap the digestive benefits, limit kefir to cold recipes.

“Kefir has several health benefits and can be a nutritious addition to your diet,” Sommer reiterates. “On the whole, it can be a delicious way to boost your overall health.”