Reviewed by Kathleen M. Zelman, RD, LD, MPH on August 22, 2022
photo of batch of fermenting kombucha cultures in

What Is Kombucha?

Kombucha is a fizzy sweet-and-sour drink made with tea. Many people say it helps relieve or prevent a variety of health problems, everything from hair loss to cancer and AIDS. There’s little scientific evidence to back up the claims, but some elements of the drink may be good for you.

Kombucha has been around for nearly 2,000 years. It was first brewed in China and then spread to Japan and Russia. It became popular in Europe in the early 20th century. Sales in the United States are on the rise because of its reputation as a health and energy drink.

Kombucha Ingredients

The basic ingredients in kombucha are yeast, sugar, and black tea. The mix is set aside for a week or more. During that time, bacteria and acids form in the drink, as well as a small amount of alcohol. This process is known as fermentation, and it’s similar to how cabbage is preserved as sauerkraut or kimchi, or how milk is turned into yogurt.

These bacteria and acids form a film on top of the liquid called a SCOBY (symbiotic colony of bacteria and yeast). You can use a SCOBY to ferment more kombucha.

Kombucha bacteria includes lactic-acid bacteria, which can work as a probiotic. Kombucha also contains a healthy dose of B vitamins.

Kombucha Health Benefits

Advocates say it helps your digestion, rids your body of toxins, and boosts your energy. It’s also said to boost your immune system, help you lose weight, ward off high blood pressure and heart disease, and prevent cancer. But there’s not a lot of evidence to support these claims.

Fermented products in general are good for the microbiome and gut health. Fermentation makes probiotics which help with diarrhea and irritable bowel syndrome (IBS), and they may even strengthen your immune system.

When kombucha is made from green tea, you get its benefits, too. This includes bioactive compounds, such as polyphenols, that act as antioxidants. Antioxidants protect your cells from damage.

Green tea may also help you burn fat and protect you from heart disease. Studies in animals show that the drink lowers cholesterol and blood sugar levels, among other things. But research hasn’t shown that it has the same effects in people.

Kombucha Risks

Making kombucha involves letting bacteria grow in a liquid you’re going to drink. Many of the bacteria are considered probiotics, but if it’s not prepared properly, it can grow harmful bacteria or mold.

Since the mid-1990s, several cases of illness and at least one death have been reported in people who drank kombucha. Ailments included liver problems, lactic acidosis (a buildup of lactic acid in the body), allergic reactions, and nausea.

The nonprofit product research group Consumer Reports advises against drinking it because of the risk of contamination and little proof of benefits.

But the FDA says kombucha is safe when properly prepared. If you’re making it at home, experts recommend using glass, stainless steel, or plastic containers. Keep everything sanitary, including the equipment and your hands.

Show Sources


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