What is the deal with Kombucha anyway?

kombucha tea health claims health benefits explained

Kombucha tea has taken the grocery stores by storm! I could easily say the same about Instagram feeds… it seems like everyone has converted to this claimed-to-be-miraculous drink. So what is kombucha tea and is it actually good for you? Let’s find out!


What is kombucha tea?

Kombucha tea is a fermented drink made with tea, sugar and a colony of bacteria and yeast (often referred to as SCOBY: symbiotic colony of bacteria and yeast). The yeast component converts the sugar to alcohol and adds a bit of carbonation. The bacteria simultaneously convert the alcohol to organic acids. This results in a slightly bubble-filled tea (with only small traces of alcohol left, store-bought has typically <1%).


What are the health claims & risks?

There are a lot of health claims for kombucha tea, mostly about how it can stimulate the immune system, prevent cancer, improve digestion and improve liver function. Other claims include therapeutic benefits for rheumatism, arthritis, insomnia, hair growth and general ageing. Although these claims all sound great… unfortunately there is very little actual evidence to support them.

In fact, there have been a few negative anecdotes about drinking kombucha tea. Some people have had allergic reactions, upset stomachs and even bacterial infections. The major problems with kombucha tea have been associated with homemade brews that are often made under non-sterile conditions, causing the batches to be contaminated. Even the type of dishes are important in the homemaking process as there have been reports of lead poisoning caused by lead leaching out from ceramic glaze. If you’re buying from a well-known brand in a store, then you have to worry less about the brewing conditions, of course.

kombucha tea health claims health benefits explained


What about probiotics?

Like other fermented foods, probiotics are present in kombucha tea and these might be why some people just generally feel better after drinking it. Probiotics aren’t only good for you – they are needed in your digestive system! Probiotics are good bacteria that help keep your digestive system healthy.

The issue with probiotics in kombucha specifically is that the drink itself is a very acid environment, which might not be conducive to the types of probiotics our body can benefit from.

The other issue with probiotics is that there are so many different strains and possible quantities of probiotics that we actually don’t really know what works and what doesn’t work. It would be impossible to have good scientific studies for every strain, combination of strains and different quantities in order to confirm what mixtures and doses are actually beneficial.


What about other good stuff?

The other argument for kombucha is that the process of fermentation always forms acetic acid and sometimes glucuronic acid (not found in all brews). Acetic acid is part of our normal energy producing metabolism. However, there is no evidence that our body needs extra acetic acid in order to function at its best. Glucuronic acid is part of our natural detoxification process but again, there is no evidence that an addition of glucuronic acid increases the removal of toxins from the body. The body makes these acids as they are needed, so there is technically no reason our body would need us to consume more of them.


Are there really no positive studies out there?

There was a study in 2009 with rats that showed protective effects of kombucha, mainly hepatoprotective effects (liver) and suggested that antioxidant molecules created during fermentation could be the reason. (Reference 4)

There was also one study done in 2000 that showed kombucha exerted antimicrobial activities against a bunch of bacteria (E.Coli included). The study concluded that there must be other stuff in addition to acetic acid causing this antimicrobial effects. (Reference 5)


kombucha tea health claims health benefits explained


Sugar, caffeine & alcohol:

You need to be aware that kombucha tea is not a low-sugar drink. Depending on the brand, there will be differing levels of sugar but considering it is the sugar itself that gets fermented… you really can’t avoid it. Just make sure the company hasn’t added any additional sweeteners. 

Black tea and green tea do contain caffeine so a by-product of that won’t be any different. 

The fermentation process will produce alcohol and while most of it will be converted, there will be traces of alcohol remaining. Depending on your province or state’s regulations, companies need to regulate the amount. Store-bought kombucha will typically be below 1% alcohol, but homemade is likely to be much higher. There was a recall from a large company a few years ago when it was discovered to be 3% alcohol.

Between the caffeine and the alcohol, pregnant people, nursing people and children are advised against drinking kombucha tea. I also found a source from British Colombia that says that the general population should not drink more than 110ml (4oz) per day. 


Final thoughts:

  1. It is safest to buy kombucha from a reputable company instead of making your own due to contamination risks
  2. It contains sugar, caffeine and traces of alcohol which might be a concern to some people
  3. There is very little scientific evidence that drinking kombucha has beneficial effects
  4. There is a lot of anecdotal evidence that drinking kombucha makes you feel better

In Conclusion: If you are aware of the risks and ensure to drink safe non-contamicated kombucha tea, then there is no reason to avoid it in moderate quantities. If it makes you feel better, then that is great for you! We just need to make sure we don’t provide generalized unproven health claims.

Thanks for reading! Let me know if you have any questions and I will try my best to answer them.


  1. Mayoclinic: What is kombucha tea? Does it have any health benefits?
  2. Wonderdrink Healthy Benefits (check out their references)
  3. BC Centre for Disease Contol: Food Safety Assessment of Kombucha Tea Recipe and Food Safety Plan
  4. Murugesan, G.S et al. Hepatoprotective and Curative Properties of Kombucha Tea Against Carbon Tetrachloride-Induced Toxicity. J. Microbiol. Biotechnol. 2009
  5. Sreeramulu, G., Knol, W. and Zhu, Y. Kombucha fermentation and its antimicrobial activity. Journal of agricultural and food chemistry. 2000.


  1. March 9, 2017 / 5:11 PM

    I’ve seen this everywhere & wondered if it was any good! Thanks for a clear and informative post!

    • rebecca
      March 9, 2017 / 5:16 PM

      Glad you found it useful! It definitely has become super trendy

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