(Picture by Jarr Kombucha. We can't get enough of the stuff!)
With the Kombucha craze coming in hard and fast, we had to ask the fundamental question. Is Kombucha really the legitimate health panacea it claims to be, or is it yet another fad doesn’t live up to its anti-ageing, gut health boosting, anti-cancer health claims?
Words by Linia Patel
First I should probably disclose that I am borderline addicted to Kombucha. So much so that I am now even brewing my own at home! However, I’m also a clinician and researcher, so whilst I do like to dabble in the latest health trends I’m also all about evidence-based advice. Phew… so now I have all my cards on the table… let’s take a closer look at the facts behind Kombucha.
What is Kombucha?
Kombucha is a fermented tea. It is made by combining tea (often a mix of green and black tea) with good mix of bacteria and yeast. A third and essential ingredient needed is that dreaded “s” work – sugar.
The use of tea as a base ingredient means that Kombucha contains some caffeine and catechins (a group of antioxidants), although how the fermentation process affects these antioxidants is not well understood. A live culture of “good” bacteria and yeasts is then added to this brew. The bacteria and yeast used is commonly known as the SCOBY (Symbiotic Colony of Bacteria and Yeast). The SCOBY change the tea brew to Kombucha, a living fermented drink high in probiotics. Interestingly, different Kombucha brands will use different SCOBY, and different SCOBY’s contain different bacterial strains and therefore possess unique qualities. This is one of the reasons why generalised health claims about Kombucha can’t really be made, because different batches contain different bacteria and are likely to have different effects.
The “added sugar” in Kombucha serves two purposes. Firstly, it is needed to keep the SCOBY alive. Secondly, through the process of fermentation the SCOBY eats the sugar. Fermentation produces a range of health boosting bio-active compounds such as B vitamins, organic compounds and some amino acids. It also generates carbon dioxide which results in that delicious Kombucha fizz!
While a lot of sugar is added in making Kombucha (my biggest surprise when brewing my own), there is usual only a small amount actually left in the final product. However, when it comes to commercially made Kombucha the amount of sugar can vary greatly. Some manufacturers will add in extra sugar to make it taste better. With this in mind, it is always important to check the nutrition label. New recommendations for added sugar intake state that that we shouldn’t have more than 25g across a whole day.
What are the health benefits?
Kombucha has been consumed for thousands of years, so maybe our ancestors were onto something that we need to learn more about. Kombucha is thought to contain a large number of healthy bacteria known as probiotics, as a result of the fermentation process. The role of microbes in our guts is an ever-growing area of research. Probiotics are thought to be beneficial for gut health, nutrient absorption, and supporting the immune system, as well as playing a role in brain and memory health, rheumatoid arthritis and even weight management.
What does the science say?
Most of the evidence we have which relates to probiotics relates to probiotics in supplement form. Unfortunately, with Kombucha there has yet to be any good quality studies (known as randomised controlled trials) done. A lot of the hype and “evidence” of its multiple health benefits have been based on personal observations, testimonials or “in-vitro” (i.e. test tubes). More human studies are needed to really see if the claims made about Kombucha are really warranted. But it is worth remembering that even though there are no good quality studies, this doesn’t mean that there are no benefits. It simply means that we need to do more research.
Are there any health risks from drinking Kombucha?
Yes, if you don’t follow the rules! This particularly applies to home brewing. Kombucha is not a product for pregnant ladies, children or anyone who has a poor immune function. Diabetics also need to watch the sugar content of the drink.
The health risks include:
- Lead and chemical poisoning if kept in the wrong container. Kombucha should only be stored in glass containers. Plastic or metal or ceramic containers should definitely not be used.
- Gastroenteritis – if the bad bacteria are allowed to flourish they are likely to cause diarrhoea and vomiting. It is therefore very important to make sure that any Kombucha made is very carefully stored.
- Toxins produced during fermentation (if made wrong) may damage the liver or kidneys.
Take home message
Kombucha isn’t a magical potion, but then again there isn’t any single food or drink that will ever be. It has however been around for centuries as a medicinal drink. So, if you enjoy the taste, it’s not doing you any physical harm and your Kombucha habit isn’t breaking the bank, then crack on! As long as you are mindful to look out for levels of added sugar, then Kombucha can certainly fit into a healthy eating plan.
Do remember that are numerous other gut-friendly foods that you can tap into as well. Being a fan of variety in your diet, I would encourage you to regularly mix up your gut-health boosting foods.
Gut health boosting foods:
- BIO-LIVE YOGHURT: Don’t underestimate this breakfast staple. Yogurt contains live and active cultures of lactobacillus bacteria that help keep your bad bacteria in check. In addition, Greek yogurt is a good source of protein and calcium.
- MISO: a paste made from fermented soybeans, is commonly used as the star ingredient in miso soup. Like other soy foods, miso is a good course of copper – a mineral with antioxidant properties.
- TEMPEH: made from fermented soybeans tempeh is high in protein but also contains a good whack of probiotics. A versatile protein sauces that soaks up flavour so a good meat alternative in stir-fries and curries.
- PICKLES: if you are the kind of person that likes to steal pickles off other people’s plates then you are likely to be getting a nice dose of probiotics and fibre with your burger. Pickles are also high in vitamin A and K. Don’t overdo it though as they tend to be high in salt too.
- SAUERKRAUT Produced as a result of lactic acid fermentation, sauerkraut is an excellent source of probiotics, fibre and iron.
KIMCHI: A Korean cuisine staple that is made from fermented vegetables like cabbage and radish seasoned with chili powder, ginger and garlic. Kimchi is loaded with vitamin A, B and C and is loaded with the “healthy bacteria” called lactobacilli.
What to learn more? Uncover the truth behind gut friendly foods >
- Vīna I, Semjonovs P, Linde R, Deniņa I. Current evidence on physiological activity and expected health effects of kombucha fermented beverage. J Med Food. 2014;17(2):179-188.
- Nummer BA. Kombucha brewing under the Food and Drug Administration model Food Code: risk analysis and processing guidance. J Environ Health. 2013;76(4):8-11