Is Kombucha All It’s Hyped Up to Be?

From grocery stores and farmer’s markets to breweries and restaurants, kombucha seems to be everywhere these days. While some people simply like the taste, many are enticed by the probiotic content and proposed health benefits. But is kombucha as healthy as it’s hyped up to be? Let’s take a look at what the research has to say.

What is Kombucha anyways?

While you have probably seen bottles at the grocery store and possibly even Kombucha on tap at your local brewery, chances are you aren’t exactly sure what it is.

Believed to have originated in China, kombucha is a fermented drink made from tea (traditionally black or green), sugar, yeast, and bacteria. The fermentation process generally takes a few weeks, and involves the yeast in the SCOOBY (a.k.a the symbiotic colony of bacteria and yeast) breaking down the sugar, resulting in a release of probiotic bacteria.

After fermentation, the SCOBY is removed, leaving behind a fizzy, slightly sour, slightly sweet beverage. Of course, many companies have started adding additional ingredients to their kombucha, creating a huge variety of flavors to choose from.

Why it’s so popular

Touted for centuries for its proposed health benefits, kombucha has historically been used to help treat a wide range of conditions from high blood pressure and gastrointestinal issues to more serious diseases, like cancer.

Today, kombucha’s popularity is largely driven by its potential probiotic effects from the fermentation process, as well as its antioxidant and possible antibacterial properties. However, there are still numerous proposed benefits including detoxification, reduced cholesterol and blood pressure levels, alleviation of arthritis, promotion of liver function, reduced appetite, enhanced metabolism, protection against diabetes, increased resistance to cancer, and improvements in hair, skin, and nail health.

It’s also popular with individuals looking for a flavored beverage that’s more interesting than water but less sugary than juice. Plus, with so many kombucha companies popping up, there seems to be an endless variety of flavor combinations to try.

Finally, just as baking homemade sourdough bread has gotten more popular, the DIY-ers out there are drawn in by the relative approachability of making their own kombucha at home.

Is it actually healthy?

But let’s get back to the main reason for the hype: potential health benefits.

We’ll start by looking at the general nutritional composition.

Keep in mind that the actual amounts of nutrients (especially sugar) will vary by flavor and brand. Always be sure to read the nutrition label, especially the serving size, as most bottles I’ve purchased (and consumed in one sitting) actually contain 2.5 servings each.

Plain kombucha has approximately 13 calories per 8 ounce serving, with 3 grams of sugar, 0 grams of fat and 0 grams of protein.

Flavored kombucha generally has more calories and sugar. For example, GT’s Enlightened Gingerade Kombucha has 25 calories and 6 grams of sugar per 8 ounces.

Kombucha also contains vitamin C and B vitamins, as well as disease-protecting polyphenols and antioxidants from the tea.

Thanks to the fermentation process, it does contain small amounts of alcohol. However, store-bought kombucha is labeled “non-alcoholic” as it contains less than 0.5% alcohol. Home-brewed kombucha, however, may contain 3% alcohol or even higher.

Probiotics and Gut Health

The most common claim I hear from clients and the media is that kombucha is a good source of probiotics and, therefore, is beneficial for gut health.

While there are currently no human studies on the probiotic benefits of kombucha, there are culture studies that have shown the beverage to contain several species of lactic-acid bacteria, which likely have probiotic activities.

For a full run-down on probiotics, be sure to check out our previous post here. Briefly, probiotics are beneficial bacteria in our guts that may improve various aspects of health, including digestion, inflammation, anxiety and depression, and body weight.

While science is still exploring the exact mechanisms of how probiotics affect health, most research supports the importance of having a diverse microbiome. So, just as eating a variety of fruits and vegetables is the key to meeting our vitamin and mineral needs, consuming a variety of probiotic-rich foods is just as essential for fostering a healthy and diverse microbiome.

But what about kombucha that is pasteurized? Unfortunately, pasteurization kills the majority of these beneficial bacteria. However, some brands add live cultures back into the kombucha after heating.

While it’s true that raw and home-brewed kombucha are a richer source of naturally occurring beneficial bacteria, its extremely important to only consume kombucha that’s been made following safe cleaning, brewing, and storing procedures. Additionally, pregnant women and anyone with a compromised immune system should avoid unpasteurized kombucha.

Anti-bacterial

Acetic acid, also found in vinegar, is a substrate formed during the fermentation process that is proposed to provide antibacterial properties to kombucha. In culture studies, kombucha has been shown to have some antibacterial and anti-fungal properties, particularly against Candida yeasts. However, there are currently no human studies that have confirmed this benefit.

Liver Health

Due to the polyphenols from the tea that kombucha is brewed from, it’s been theorized that kombucha may play a role in helping the liver process and get rid of toxins in the body. While a few rat studies have shown that regular consumption of kombucha reduces liver toxicity from chemical toxins, these results have not been replicated in humans.

Heart Health

Dating back to the World War Two-era, kombucha has been used to help reduce cholesterol and blood pressure levels. However, besides anecdotal evidence and rat studies, there’s currently no actual research in humans to support these claims.

Type 2 Diabetes Risk

As the prevalence of type 2 diabetes continues to grow, so does research into alternative methods for prevention and treatment. A 2012 study found that, compared to regular black tea, kombucha resulted in reduced blood sugar levels and improved kidney and liver function in diabetic rats. However, there have yet to be human studies on the role of kombucha on the prevention or treatment of type 2 diabetes.

Cancer Prevention

While it’s been suggested that kombucha can help prevent the growth and spread of cancer cells, this is another instance where there are currently no human studies supporting this claim. One test tube study did show that kombucha exhibited antioxidant effects, slowing the growth of breast cancer cells. However, much more rigorous, human trials are needed before this proposed benefit can be supported.

Furthermore, it’s important that those currently with cancer avoid raw, unpasteurized kombucha as there is risk for infection.

Are there potential dangers of drinking Kombucha?

As home-brewed kombucha is unpasteurized and may be higher in alcohol, it’s recommended that pregnant women avoid it and choose a store-bought kombucha instead.

Kombucha also contains small amounts of caffeine, anywhere from 2-25 mg per serving. While this is much lower than coffee, if you are trying to avoid caffeine it’s worth being aware of.

Most of the potential dangers come from making your own kombucha. It’s essential to use sterile equipment and purchase your SCOBY from a trusted source. If you get a SCOBY from a friend, make sure that there aren’t any black spots or signs of mold.

Other important safety tips for making your own include using a glass container to make and store your kombucha, as the acidity from the kombucha can cause leaching of potentially dangerous compounds from other materials. Getting your kombucha to the correct pH and keeping it well-covered are also key to avoid the growth of potentially dangerous bacteria.

Finally, it’s important to do your research before adding your own flavorings to homemade kombucha, as certain ingredients are more likely to contain or attract mold or bacteria than others.

Bottom Line

Due to the lack of human studies, there’s currently insufficient evidence to support the majority of health claims surrounding kombucha. However, as kombucha does contain polyphenols and is often a lower calorie and sugar option than sugar or soda, it can fit into a healthy lifestyle. As the nutrient profile varies by brand, it’s important to still keep an eye on nutrition labels and portion sizes.

For those looking specifically for a gut health-boost, raw kombucha does provide beneficial lactic-acid bacteria. However, other probiotic-rich foods are also needed in the diet in order to have a healthy, diverse microbiome.