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Updated: Jul 17, 2023

I personally enjoy drinking kombucha! It contains beneficial bacteria, yeast, organic acids, vitamins and polyphenols.

Although this drink is a type of carbonated tea that has been consumed around the world for thousands of years, it seems to have made quite a comeback lately and people are promoting it as the next big miracle cure for everything from gut health to mental health. Is there any proof to the hype? Is kombucha a magic probiotic potion that will be your fountain of youth? What about reports of liver toxicity and of this tea turning your blood to acid? There have been case reports of deaths linked to kombucha consumption. Let’s review what kombucha is, what it contains, and how it affects your body.

What is Kombucha?

Kombucha is made my combining tea, sugar (sometimes in the form of fruit) and micro-organisms that ferment the sugars to produce beneficial nutrients and chemical compounds. The micro-organisms are called a SCOBY, which means “symbiotic culture of bacteria and yeast”. Some people refer to it as mushroom tea, but there are no mushrooms in it. The SCOBY will start fermenting the sugars, in much the same way as brewer’s yeast ferment grains in beer. Other fermented foods include sauerkraut and kimchi just to name a few. This tea, dubbed the “tea of immortality”, has been around for thousands of years. Reported to have started in China, it has now spread to the Americas and is now in the firm grasp of huge food and beverage corporations. It has grown into an almost 500 million dollar industry in the USA over the last 7 years. Is this a clever marketing scam, or are there actual health benefits to consuming kombucha?

Health implications of kombucha

Kombucha has been reported to cure everything from the common cold to cancer, but are any of these claims legit? Is there any science backing them up? When sales are good, most companies will want to avoid spending millions of dollars on studies that could potentially disprove the alleged benefits they use to market their products, and so research remains intentionally rare. Independent and unbiased researchers are the ones left to find funding or grants to make these studies happen and that’s the only way we’ll ever get clear and unbiased conclusions.

When looking at the actual peer reviewed science on kombucha, one quickly notices that good studies are lacking. After looking at the levels of scientific proof and the weight of evidence they provide, most will agree that anecdotal reports and expert opinion are amongst the lowest and weakest forms of proof, and unfortunately for kombucha, that’s pretty much all the evidence we have.

Studies on kombucha are lacking, and those that exist weren’t randomized or controlled or tested against placebos. Although solid proof doesn‘t exist for kombucha, most of its individual nutrients do have solid evidence backing their beneficial health claims. Black or green tea, acetic acid, antioxidants, polyphenols and B vitamins already have plenty of proven health benefits and are present in large concentrations in kombucha. More studies will have to confirm the purported health claims, but that doesn’t keep me from consuming it responsibly. One can extrapolate from existing data that kombucha is likely to be safe to drink and is likely to have some benefits for gut health due to its probiotic content, and likely to have other benefits due to its antioxidant, vitamin and polyphenol content. As stated earlier, absolute “proof” relies on the best possible evidence, which comes from well designed studies, like randomized controlled trials, meta-analysis and systematic reviews. The proof is missing, because these studies simply don’t exist, but that doesn’t mean regular and responsible consumption can’t be of great benefit for your health.

Potential risks of kombucha

Generally considered to be safe, kombucha has been reported to have negative health effects in certain people. Although the bacteria in kombucha are considered to be probiotic, if not prepared properly, it can grow harmful bacteria and mold and can be very dangerous. That’s why you should purchase your kombucha from local and reputable companies, like Valk Fermentation or Greenwhale kombucha in south-east New-Brunswick. Contaminants are more likely when people prepare it at home under non-sterile conditions. Cases of illness and death have been reported with poorly prepared kombucha and those with kidney or immune conditions should talk to a health professional before consuming. People shouldn’t rely on kombucha for hydration and should treat it like any other medicinal supplement. The benefits are assumed to come from the regular consumption of small amounts, rather than chugging down a bottle in one sitting. Kombucha does contain minimal amounts of alcohol, and this must be taken into account if you’re pregnant, nursing, a child, or have liver or pancreatic conditions, or if you’ve had prior issues with substance abuse.

If you’re gonna brew at home, use caution. If prepared under the wrong conditions, there can be risks associated with the overconsumption of kombucha. That’s precisely why I choose to purchase mine from local businesses like VALK FERMENTATION and GREENWHALE KOMBUCHA. They prepare their beverages under strict, yet simple conditions, without additives or preservatives and without added sugar. These unwanted compounds are frequently found in kombucha coming from large scale producers. So I’d suggest avoiding kombucha bought from companies you don’t know, or from large scale producers. Support your local kombucha producers, since they consume their own products, gift it to their families and have your best interest at heart.

The scientific evidence behind kombucha

When looking at studies on cigarettes, one might be surprised that many studies actually show smoking to be not only harmless, but having health promoting effects! If you find this suspicious, then you’re on the right track. In fact, 90% of studies having shown benefits of smoking were funded by the tobacco industry or its affiliates. It’s easy for massive corporations to avoid disclaiming conflicts of interests when they have multiple layers of holding companies financing these studies for them. One study has shown that research funded by the tobacco industry was 88 times more likely to show no harm from smoking. What does that have to do with kombucha!? When looking for the best scientific evidence, like systematic reviews or randomized and placebo controlled trial, one quickly notices that there are none to be found. That’s right, most of the alleged benefits from kombucha are coming directly from those who stand to benefit the most…those who sell it. I’m not saying kombucha is evil, or that companies selling kombucha are out to get you. Quite the contrary actually. I consume it regularly and do feel like it can play a role in one’s gut health. When making recommendations, doctors hope they can rely on the best available evidence and we only hope that there are systematic reviews, meta-analysis or randomized controlled trials that back up our recommendations. We wouldn’t recommend a specific chemotherapy simply because we heard that it helped someone somewhere with their symptoms. That would be very irresponsible. So if you’re looking for undeniable and irrefutable scientific proof that kombucha is healthy, safe and worth your money and time, I’m sorry to report that this doesn’t exist. Some studies have reported serious side effects after excessive consumption and even rare severe illness and death. One has to weigh the possible benefits versus the super rare, but super dangerous risks. You wouldn't drink two liters of red bull or soda in a day, and the same goes for kombucha.

My kombucha conclusion

I personally enjoy drinking kombucha. I use it because I like it and because I truly believe in the science behind its benefits. I’ve seen and felt how it helps improve my gut health and can fit it easily in my routine. But if you’re not enjoying it and simply using it for it‘s health claims, then you might want to rethink your health plan. Kombucha makers want us to guzzle it down, but this drink should be enjoyed responsibly. It does come with certain possible down sides, but adding various beneficial bacteria and yeast to your gut flora might help in making it healthier. The drink is highly acidic and I’d recommend drinking it through a straw as to minimize damaging the enamel of your teeth or diluting it with water. I often add a quarter cup of water to my kombucha to make it more palatable and easy on my system. I never drink more than 125-250 ml, or half a cup to a full cup, in one day. I treat it like medicine, or a supplement, and I stick to what I know is a safe and evidence-based dosage range. Individual components of kombucha have been studied independently and found to have great benefits, but more studies on kombucha itself are needed to offer any solid conclusion. In a perfect world, kombucha would be studied in randomized controlled trials where people are randomly assigned to receive either kombucha or placebo. This makes it much easier to tease out what claims are hype versus science. If you enjoy kombucha, then keep on consuming it responsibly, but if you don’t enjoy it, and are simply using it for its alleged probiotic health claims, maybe you can focus on adding more fermented plant foods like sauerkraut or kimchi, or eating a wide variety of plant foods since they already have proven benefits.

Thanks for reading and sharing with your kombucha drinking friends!

If you’d like to support a local business that makes awesome kombucha, please check out Valk Fermentation and Greenwhale on Facebook or Instagram. They’re your New-Brunswick sources for all things fermented, and they specialize in products like soaps, vinegars, fermented vegetables and kombucha.

Check out my website and look for the “How To” section in the menu. There, you’ll find tips and tricks that helped me on my journey towards a plant-predominant diet. Everything there is completely free, no catches! If you're looking for healthy high protein plant-based recipes, check out and download my free recipe eBook!

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Plant-based Dr Jules🌱💚

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