Kombucha is a fermented tea that has been consumed for thousands of years.
Not only does it have the same health benefits as tea — it's also rich in beneficial probiotics.
Kombucha also contains antioxidants, can kill harmful bacteria and may help fight several diseases.
Here are the top 8 health benefits of kombucha, based on scientific evidence.
Kombucha is thought to originate in China or Japan.
It's made by adding specific strains of bacteria, yeast and sugar to black or green tea, then allowing it to ferment for a week or more ().
During this process, bacteria and yeast form a mushroom-like film on the surface of the liquid. This is why kombucha is also known as "mushroom tea."
This blob is a living symbiotic colony of bacteria and yeast, or a SCOBY, and can be used to ferment new kombucha.
The fermentation process produces acetic acid (also found in vinegar) and several other acidic compounds, trace levels of alcohol and gases that make it carbonated ().
A large amount of bacteria also grow in the mixture. Although there is still no evidence for the probiotic benefits of kombucha, it contains several species of lactic-acid bacteria which may have probiotic function. ().
Probiotics provide your gut with healthy bacteria. These bacteria can improve many aspects of health, including digestion, inflammation and even weight loss.
For this reason, adding beverages like kombucha to your diet might improve your health in many ways.
Summary Kombucha is a type of tea that has been fermented. This makes it a good source of probiotics, which have many health benefits.
Green tea is one of the healthiest beverages on the planet.
This is because green tea contains many bioactive compounds, such as polyphenols, which function as powerful antioxidants in the body ().
Kombucha made from green tea contains many of the same plant compounds and presumably boasts some of the same benefits ().
Studies show that drinking green tea regularly can increase the number of calories you burn, reduce belly fat, improve cholesterol levels, help with blood sugar control and more (, , , ).
Studies also show that green tea drinkers have a reduced risk of prostate, breast and colon cancers (, , ).
Summary Kombucha made from green tea may offer many of the same health benefits as green tea itself, such as weight loss and blood sugar control.
Antioxidants are substances that fight free radicals, reactive molecules that can damage your cells (, ).
Many scientists believe that antioxidants from foods and beverages are better for your health than antioxidant supplements ().
Kombucha, especially when made with green tea, appears to have antioxidant effects in your liver.
Rat studies consistently find that drinking kombucha regularly reduces liver toxicity caused by toxic chemicals, in some cases by at least 70% (, , , ).
While no human studies exist on this topic, it does seem like a promising area of research for people with liver disease.
Summary Kombucha is rich in antioxidants, and studies have shown that it protects rats’ liver from toxicity.
One of the main substances produced during the fermentation of kombucha is acetic acid, which is also abundant in vinegar.
Like the polyphenols in tea, acetic acid is able to kill many potentially harmful microorganisms ().
These antimicrobial effects suppress the growth of undesirable bacteria and yeasts, but they do not affect the beneficial, probiotic bacteria and yeasts involved in kombucha fermentation.
The health relevance of these antimicrobial properties is unclear.
Summary Kombucha is rich in tea polyphenols and acetic acid, which have both been shown to suppress the growth of undesirable bacteria and yeasts.
Heart disease is the world's leading cause of death (22).
Rat studies show that kombucha can greatly improve two markers of heart disease, “bad” LDL and “good” HDL cholesterol, in as few as 30 days (, ).
Even more importantly, tea (especially green tea) protects LDL cholesterol particles from oxidation, which is thought to contribute to heart disease (, 26, ).
In fact, green tea drinkers have up to a 31% lower risk of developing heart disease, a benefit that may also apply to kombucha (, , ).
Summary Kombucha has been shown to improve “bad” LDL and “good” HDL cholesterol levels in rats. It may also protect against heart disease.
Type 2 diabetes affects over 300 million people worldwide. It is characterized by high blood sugar levels and insulin resistance.
A study in diabetic rats found that kombucha slowed down the digestion of carbs, which reduced blood sugar levels. It also improved liver and kidney function ().
Kombucha made from green tea is likely to be even more beneficial, as green tea itself has been shown to reduce blood sugar levels ().
In fact, a review study of almost 300,000 individuals found that green tea drinkers had an 18% lower risk of becoming diabetic ().
Further human studies are needed to investigate the benefits of kombucha for blood sugar control.
Summary Kombucha improved several markers of diabetes in rats, including blood sugar levels.
Cancer is one of the world's leading causes of death. It is characterized by cell mutation and uncontrolled cell growth.
In test-tube studies, kombucha helped prevent the growth and spread of cancerous cells due to its high concentration of tea polyphenols and antioxidants (, 34).
How the anti-cancer properties of tea polyphenols work is not well understood.
However, it's thought that the polyphenols block gene mutation and growth of cancer cells while also promoting cancer cell death (35).
For this reason, it is not surprising that tea drinkers are much less likely to develop various types of cancer (, , ).
However, whether kombucha has any anti-cancer effects in people has not been confirmed. Further studies are needed.
Summary Test-tube studies show that kombucha may suppress the growth of cancer cells. It is unknown whether drinking kombucha has any effects on cancer risk in people.
Kombucha is a probiotic-rich tea with many potential health benefits.
You can purchase it in stores or make it yourself at home. However, be sure to prepare it properly.
Contaminated or over-fermented kombucha can cause serious health problems and even death. Homemade kombucha may also contain up to 3% alcohol (, , , ).
The safer option is to buy kombucha at a store or online. Commercial products are tasty and considered alcohol-free, as they must contain less than 0.5% alcohol ().
However, check the ingredients and try to avoid brands that are high in added sugar.
Summary Improperly prepared kombucha may have adverse health effects. A safer option is to buy bottled kombucha at the store.
Many people believe that kombucha helps treat all sorts of chronic health problems.
However, human studies on the effects of kombucha are few and the evidence for its health effects limited.
In contrast, there is ample evidence for the benefits of tea and probiotics, both of which are found in kombucha.
If you decide to try homemade kombucha, make sure it’s properly prepared. Contaminated kombucha may cause more harm than good.