First, what is kombucha?
Kombucha is a beverage that originated in China as far back as 2,200 years ago. It’s been popular all this time because of its apparent energizing and detoxifying properties.
This tea-based drink eventually found its way to Russia and Europe as trade routes expanded. It became popular in Germany, France, and northern Africa around the 1950s.
Kombucha begins as either a green or black tea. White sugar is then fermented for 1-2 weeks, which creates what some call a “tea fungus” or symbiotic culture of acetic acid bacteria and yeast (SCOBY).
This process changes the polyphenols, which are normally found in fruits and vegetables, into different organic compounds. It’s these new organic compounds that are what people claim gives kombucha its health benefits.
People who have tried kombucha describe its taste as a vinegar-y apple cider.
The purported health benefits of kombucha
All the hype has to come from somewhere, right? Here are some of the reported benefits of kombucha, reinforced with studies where possible:
- Some people, even celebrities, have touted kombucha as a cancer-killer.
- Nutritionist Monica Reinagel says people even claim it’s a fountain of youth beverage, staving off aging and restoring vitality.
- Others say the probiotics in kombucha help with digestion and prevent illness.
- Animal research studies show that kombucha lowers LDL (“bad”) cholesterol. LDL cholesterol has been linked to heart disease for years.
- Some studies indicate that kombucha’s natural antioxidants can suppress cancerous cells. However, it’s worth noting that these were test tube studies and not human studies, so at this time no one can claim this with certainty.
- Blood sugar levels – people say that kombucha helps control how much sugar enters the bloodstream, which is beneficial. However, this hasn’t been proven in human tests.
- One animal study found evidence that kombucha helped to protect the liver against harmful substances.
It’s important to note after listing these that just because something is healthy doesn’t mean it has healing properties.
Doctors do say that probiotics can positively affect digestion, so kombucha probably does have that going for it.
Does kombucha contain alcohol?
The fermentation process does generally make compounds alcoholic to varying degrees (as sugar breaks down into alcohol and carbon dioxide). In this case, however, kombucha is less than 0.5% alcoholic (compared to the roughly 5% ABV of beer).
Beverages that contain 0.5% or less alcohol by volume are considered non-alcoholic in some countries, but is regulated in the U.S.
So, yes kombucha does contain small amounts of alcohol, but you’re not going to get drunk while enjoying it.
Are there health risks to kombucha?
Home brewed kombucha is known to contain up to 3% alcohol — almost as much as beer by volume. That’s fine if that’s how you like it, but less so if you were expecting the kombucha the way it’s often sold commercially.
Though there are conflicting opinions about consuming alcohol while pregnant, most federal agencies recommend against it.
Not all kombucha is pasteurized, either. This means potentially harmful bacteria could be present in it, which some say can be problematic for seniors, young children, or those with weakened immune systems.
Some studies have linked tyramine, a naturally occurring amino acid, to incidences of migraines. You can find tyramine in various fermented foods, including kombucha.
That’s not to say drinking kombucha will give you migraines, but if you experience chronic migraines and find that they are set off easily, you may want to avoid kombucha, or at least consume it in moderation.
A clinical review published in 2003 says that while clinical tests on the health benefits of kombucha were limited, the results did not support the health claims made. Two out of 28 study participants experienced adverse effects, such as suspected liver damage and metabolic acidosis.
The latter condition is when there is too much acid in the body, often when the kidneys are not functioning properly to filter the acid out.
Review and conclusion
Wording in these studies matters. A food or supplement may contain things that are known to have positive effects on the body, but that’s a different statement than a study showing that the food or supplement itself helped people heal or overcome illness.
Think of it like this. Those in the medical science field often agree that antioxidants are beneficial to the body and may event help prevent cancer. But that’s not the same thing as saying taking antioxidants will definitely prevent cancer, or will cure cancer.
There have been no clinical studies to concretely reinforce any of the health benefits claimed about kombucha.
So ultimately it seems pretty inconclusive. There’s not sufficient evidence to suggest that kombucha is harmful, especially not when consumed in reasonable frequency. But likewise, there’s nothing conclusive about the hype surrounding this fermented beverage, either.