Just a Trend? What Research Tells Us About Kombucha's Health Benefits

As the hype surrounding probiotics continues to soar so does our appetite for bug-laced fermented foods and drinks, including trendy kombucha. The probiotic-rich fermented tea has become way more visible in recent years as a bevy of brands have muscled their way onto beverage shelves with a rainbow of colors and enticing flavors.

Here’s the thing: I adore kombucha. The first time I sipped the vinegary drink after a hard-charging bike ride I was smitten. It contains the perfect blend of tang, sweetness, and effervescence. I also convinced myself that it’s gotta be relatively healthy. After all, it has probiotics, right? Marketing words like “detox” and “renew” made it even easier to swallow the high price tag. It offered a much more interesting way to stay hydrated than yawning tap water.

Adherents and wellness gurus are quick to position the drink as a healthier alternative to soda, trumpeting its legitimate health benefits all over social media. Believe the hype and you’d think kombucha has the power to do everything from improve digestion, ease anxiety, fend off cancer, detox the body (whatever that means), and even help zap your belly fat. This has helped sales of the ancient brew skyrocket and transcend hipster status. (The worldwide kombucha market is expected to hit $2.4 billion by 2027, according to a 2020 market analysis report by Grand View Research.) All the cool kids are strolling around farmers’ markets and finish lines with the flashy glass bottles. Hard kombucha is now a thing so you can get a fizz and buzz at once. Really, it’s only a matter of time until we have alcoholic sports drinks.

But is this bracing brew the health elixir that it’s hyped to be? Or is it just another wellness trend that is bound to fizzle out? Read on as we try to separate the science from the sales pitch to help you (and me!) decide if you need more of the fizzy pop in your life. 

What Exactly is Kombucha?

Kombucha is thought to have originated in China or Japan. It’s made by adding certain strains of bacteria and yeast along with sugar to tea, then allowing it to ferment for a week or more. The SCOBY—which resembles a jelly-like pancake (yum!) and stands for symbiotic culture of bacteria and yeast—sits at the top of the brew, feeding on the sugar and trapping in air, which allows the fermentation process to occur. It has a slightly sour, almost vinegar-like taste, and most brands will include other flavorings like hibiscus, ginger, or lime. 

Is Kombucha as Healthy as They Say?

The positive swell behind this fizzy drink is largely owing to its probiotics. These are a colony of bacteria and yeast in the drink that once consumed can fertilize your digestive tract with beneficial critters that may play a role in digestive health and immune system regulation. Researchers have speculated that our gut microbiome is also involved in brain health, weight loss, increasing our absorption of essential nutrients, and can maybe even play a role in athletic performance.

So proponents say a daily kombucha habit can help tilt the balance in our guts in favor of the beneficial microorganisms, leading to better health including a few lofty claims that make the drink seem like the ultimate panacea. The truth will be a bit of a gut punch for anyone who believes kombucha is a miracle beverage.

Indeed, kombucha can be a convenient way to welcome more probiotics into your life, especially if you don’t eat much yogurt and other fermented foods. You just need to keep in mind that there is a chance the strains of microorganisms in the drink aren’t the ones you need most or at levels shown to be beneficial in research papers. There are countless strains of probiotics out there. So perhaps your microbiome could use an extra hit of the bugs shown to help bolster immunity in athletes but how can you be sure you’re getting those in your kombucha of choice? 

It’s also hard to know how many live probiotics you are getting in that pricey bottle of ginger kombucha. Some reports say it typically contains about a billion or so probiotics, but can certainly be more or less depending on the brand. (Some brands may add in more probiotics after the fermentation period.) That sounds like plenty, but you should know that certain probiotic supplements claim they contain up to 400 billion. Milk kefir likely contains not only a denser population of bacteria but also a greater diversity. And if you just consume a bottle or two a week it might not be enough to make any noticeable difference to your microbiome. Plus, the probiotics that are alive at the time of bottling might be dead by the time you twist the cap off a bottle of kombucha.

Owing to its tea origins, kombucha may contain cell-protecting antioxidants including polyphenols. A recent investigation in the journal Antioxidants analyzed the chemical profiles of various types of kombucha made from various kinds of tea and fermented for different amounts of time. While levels of polyphenols and flavonoids varied significantly depending on what kind of tea the kombucha was made from (red and green tea had the most) and how long the kombucha fermented, all types did have significant levels of these antioxidants which may confer some protection against certain health conditions and improve recovery from training. 

The fermentation process produces acetic acid which is also found in vinegar. A new meta-analysis review study in the Journal of the Academy of Nutrition and Dietetics found that between 750 and 3600 milligrams of acetic acid consumed daily can help lower blood triglycerides, a risk factor for heart disease, in overweight people and those with type 2 diabetes and also improve blood sugar control in diabetics. But many studies have suffered poor methodology and it’s not known what impact acetic acid has on normal weight, healthy people or just how much acetic acid a typical kombucha contains. 

We have to be upfront here, this is a case where the sales pitch has outpaced the science. To date, many of the scientific studies regarding the potential health impacts of kombucha have been conducted on rodents, not humans. So there is little in the way of any solid evidence to back up most of the grandiose health claims. Honestly, it would be pretty much impossible for any drink or food to live up to all the good deeds bestowed upon kombucha. Sure, the drink might be pretty good for us but we just don’t have any randomized human studies to say how good. The benefits of probiotics and antioxidants, in general, may not apply to kombucha specifically. Most people who guzzle kombuncha are already likely living healthier lifestyles so the chances it is going to make a major health impact is slight. 

Kombucha can have a slightly sour, almost vinegar-like taste so some brands add generous amounts of sugar and fruit juice to make it more palatable to the masses and, in turn, rendering the drink closer to soda. This is of concern because added sugars in our diets in liquid form appear to be especially detrimental to long-term health. For instance, research in the Journal of the American Heart Association found women who had one or more sugar-sweetened beverages per day had an almost 20% higher risk of cardiovascular disease, compared with women who did not consume or rarely consumed sugar-spiked drinks. Though it’s likely that if your overall diet is healthy and full of whole foods the detrimental impact sugary drinks have on health is diminished. Brands may add sweeteners like organic cane sugar post-fermentation claiming this is better than the more highly refined stuff like high fructose corn syrup you’ll find in many sodas. But, really, sugar is sugar. 

But not all the kombucha on store shelves are sugar bombs. Ideally, you want to look for a drink with no more than 8 grams of sugar per serving (about 8 ounces), keeping in mind that some bottles base their nutrition facts on two servings. Chug back a whole bottle and you could be into the sugar red zone.  Perhaps, the best time to drink a sweetened kombucha is after a hard workout as the sugar will be used to help replace spent carbohydrate stores.  

To be fair, the bubbly drink typically delivers fewer calories and sugar than soda or juice, since a good chunk of the sweet stuff added at the beginning of production gets lost in the fermentation process. The real concern is the sugar added following fermentation. 

A kombucha habit may drive up your dental bills. Dentists will caution that kombucha is nearly as acidic as soda pop, energy drinks, and sports drinks which can upset the pH level of the saliva in your mouth. When the saliva level becomes more acidic it becomes a breeding ground for bacteria which can contribute to tooth enamel loss and decay. But it need not rot your teeth. A good guideline to follow is to rinse your mouth with water after drinking kombucha to help wash away acidic compounds and avoid eating or brushing for at least 30 minutes afterward, allowing time for your tooth enamel to remineralize and reharden.

If you are a kombucha newbie it’s best to ease into it by sipping only about four ounces per day to get your digestive system used to it. Too much, too fast can lead to stomach woes like excessive gas, diarrhea, or bloating. Also good to know: because kombucha is fermented it does contain small amounts of alcohol (some brands have more than others), so those with a history of alcoholism should steer clear. It goes without saying that this includes hard kombucha. 

Kombucha’s Health Benefits: The Bottom Line

Even though kombucha contains some good stuff like probiotics and antioxidants, many of the health claims surrounding the drink are suspect. It’s a good idea to drink it simply because you enjoy kombucha instead of thinking of it as the ultimate health tonic no matter what those influencers may have to say. As always, it boils down to the fact that a nutritious overall diet, not a single food or beverage, will deliver the most bang for your buck when it comes to health and performance.