Kombucha: a nice addition to a real food lifestyle

Kombucha’s fizzy, sweet taste makes it a popular starting point for anyone who wants to delve into fermented foods but has not got their taste buds around sauerkraut or raw apple cider vinegar. But is it as good for you as the other, arguably less palatable, fermented products?

What is it?

Kombucha is like the modern-day ginger beer, though it has been around since 220 BC. It is the process of adding both bacteria and yeast (a fungus called ascoby — symbiotic culture of bacteria and yeast) into a mixture of black or green tea and sugar, which is left to ferment in a warm environment.

As the drink develops, a new culture is formed on top of the older one (the “daughter” culture) as a thin rubbery-like membrane on the surface of the mixture. After 5-14 days (or up to 30 days) it is removed and placed in some of the fermented tea to be used again, while the remaining liquid is filtered and refrigerated, ready to use as is, or with the addition of juice, fruit or other flavour enhancers.

Kombucha contains (among other things) acetic acid bacteria (such as gluconacetobacter), yeasts (including saccharomyces) and lactic acid bacteria (such as lactobacillus). As each ferment is different, the amounts (and a complete profile of bacterial strains) is difficult to determine for each batch made.

What are the health benefits?

It has long been considered a health tonic, and though there are many reported health benefits of consuming kombucha, these have been initially observational or anecdotal in nature.

Over the past few years, however, scientists have become interested in quantifying the presence of active components in the brew and their mechanism of action to test whether the reported benefits hold up in research.

The acids in kombucha could offer particular health benefits. Glucuronic acid is involved in the detoxification pathways in our digestive tract, packaging up the metabolites from environmental and pharmaceutical toxins so they are removed, preventing them from being absorbed by our tissues and the potential for harm.

Glucuronic acid is also produced naturally by our liver, yet the amount produced reduces as we age, therefore consuming kombucha could be beneficial for an older population. The substantial amount of acetic acid that is also present in kombucha may help the body absorb iron from food, lower the blood glucose response to a carbohydrate-dominant meal and stimulate digestive processes in the body.

It has high anti-microbial activity, which is beneficial for protecting us against food pathogens and gastric illnesses. Laboratory analyses of kombucha have found the drink contains the antioxidants vitamins E, C, beta-carotene and phenolic compounds.

Antioxidants play an important role in removing the body of free radicals, caused when there is undue oxidative stress. A poor diet, physical inactivity, environmental stress, excess alcohol and smoking are all causes of oxidative stress and therefore it makes sense that any increased consumption of dietary products that provide these antioxidants is going to be helpful.

It’s fair to say, however, that any claims that drinking kombucha will cure conditions due to oxidative stress are stretching the truth. These antioxidants listed are present in abundance if the diet eaten is based on a foundation of vegetables with some fruit, nuts, olive oil and animal protein.

It has also been stated that the presence of B vitamins provide energy — B vitamins are indeed involved in energy metabolism in the body, and can help in times of undue stress; however the amounts in kombucha are negligible and any energy boost may well just be due to the fizzy nature of the drink (a kind of placebo effect, where you think you feel more energised) or the sugar present in the drink.

This doesn’t mean there is no benefit from the vitamins or antioxidants in the drink, just that it should not be relied on for these dietary constituents. That said, it can be a good way to introduce fermented products to someone new to them, and though most reported health benefits are anecdotal, I wouldn’t dismiss the many people who observe beneficial effects with their digestion and energy levels when they regularly consume it.

Is the sugar content something to be concerned about?

The amount of sugar varies depending on the ferment and whether any juice has been added after fermentation. The longer the ferment, the less sugar is left once the yeast has eaten it up. A study measuring the process found that in the earlier days of the ferment, the bacteria produced enzymes to split the sugar (sucrose) into glucose and fructose.

After 7-10 days, the yeast started to eat the sugar. At around 15 days fermenting there were 4 teaspoons of sugar in 250ml of the kombucha. After 30 days, there was very little sugar left. Some manufacturers add sugar back in to alleviate the sour flavour of the brew, which will negate any claims of low sugar.

It is fair to say the sweeter the taste, the higher the content of sugar. Those mindful of their sugar intake want to look for a brew that has 3g of sugar per 100ml (ideally) or less. Though it is sold in bottles of between 250-400ml, as a health tonic I would suggest consuming around 100ml daily. Diluting kombucha with filtered water can be a good way to introduce it to children.

Can you have too much?

There have been reports of illness from unhealthy pathogens present in kombucha that has been brewed in unsterile conditions. However, if you are buying a commercial product this is not of concern. If you are trying to lower your overall sugar intake, it would be better to get your ferments in the form of sauerkraut, raw apple cider vinegar and water kefir, as opposed to kombucha.

And kombucha can be problematic for people who have a histamine intolerance (as all fermented food products can be). While kombucha is not an elixir of health, it shouldn’tbe dismissed as a health “fad” that has no evidence supporting the benefits.

Meanwhile, there are many good quality New Zealand kombucha brands out there, which are really delicious, and it is becoming increasingly available, including on tap at some establishments, making it a potential alternative to an alcoholic beverage that is lower in sugar than soft drinks. It can make a nice addition to your real food lifestyle.

For more see

• Scoby drinks and other fermented foods
• Making and cooking with sauerkraut
• Fermented foods that will help your gut

Through her subscription service of meal plans and nutritional support, nutritionist Mikki Williden helps people manage their diets in an interesting way, at a low cost. Find out more at mikkiwilliden.com