Two cups of kombucha, topped with a lemon slice and a green garnish. On a chopping board with ginger and lemon's sliced.

Kombucha benefits

Kombucha is a fermented tea drink with an acidic flavour and slight fizz, which is increasingly popular among the health-conscious. As kombucha has a low calorie and sugar content1, it’s an excellent choice for consumers looking for an alternative to water, without any bad-for-you ingredients.

In this article, we’ll explain what kombucha is, why it’s so popular, and investigate the health hype surrounding it. Then, we’ll hear what side effects kombucha has, and who might want to avoid this fermented beverage.

What is kombucha?

Kombucha is made from tea fermented with sugar and a bacterial culture called a SCOBY (symbiotic colony of bacteria and yeast). The fermentation process takes between 7 to 14 days.

Both green and black teas are used to produce kombucha. Homebrewers typically prefer to use black tea, as it ferments faster.

Black tea varieties typically have a deeper flavour. In contrast, green tea kombucha has a more delicate flavour and an almost grassy quality that some drinkers love.

Why is kombucha popular?

Fermented drinks have grown in popularity over the past decade as emerging science highlights the benefits of probiotics2. The world consumed over 18 kilotonnes of probiotics in 20183! Kombucha has likely benefited from its association with the probiotic food trend. This fermented tea has become increasingly fashionable in the United Kingdom, so much so that an estimated 1,000 British pubs sell kombucha to health-conscious consumers4.

What is kombucha good for?

Kombucha has been linked to a whole host of health benefits. This is how kombucha can support you in your healthy lifestyle:

Source of probiotics

Fermented foods are made from bacterial cultures which produce probiotics during the fermentation process, and kombucha is no exception. Although probiotic content is linked to better health outcomes5, no current evidence proves kombucha provides effective probiotics for health6  

Antioxidant content

Both green and black tea contains antioxidants called polyphenols, which have been linked to cardiovascular health7. Although studies show kombucha’s fermentation process enhances tea’s antioxidant properties8, there’s no conclusive evidence which proves kombucha’s polyphenol content positively impacts health.

Vitamin and mineral content

Kombucha contains essentials minerals, including zinc, copper, magnesium, iron, nickel, and cobalt. Vitamins B1, B6, B12 and Vitamin C are also present9.

Potential kombucha side effects

Kombucha can cause adverse effects in some drinkers. These may include:

  • Stomach pain
  • Allergic reaction
  • Nausea
  • Dizziness
  • Headache10
However, scientific studies show the majority of sufferers either had a pre-existing illness11 or drank a contaminated batch of kombucha12.

Who should avoid kombucha?

People with gastric and kidney complaints are more likely to suffer an upset stomach from drinking kombucha than non-sufferers13. Pregnant women may choose to avoid kombucha because of the alcohol content. However, it’s thought to be too low a concentration to affect a fetus. Shop Drink

Last Updated: 22nd January 2021


Author: Bhupesh Panchal, Regulatory Affairs

  • Joined Holland & Barrett: April 2019
  • Qualifications: Masters Degree in Toxicology, BSc Hons in Medical Biochemistry

Bhupesh started his career as a clinical toxicologist for Public Health England, advising healthcare professionals all around the country on how to manage clinical cases of adverse exposure to supplements, pharmaceuticals, cosmetics, industrial chemicals and agricultural products. After 7 years in this role and a further year working as a drug safety officer in the pharmaceutical industry, Bhupesh joined Holland & Barrett as a Senior Regulatory Affairs Associate in 2019.

Bhupesh specialises in vitamins & minerals nutrition, health benefits & safety of botanicals and traditional herbal medicines. View Bhupesh's LinkedIn profile. In his spare time, Bhupesh likes to cycle and has been learning to speak Korean for several years.


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