Kombucha

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.

Claims about kombucha’s power to aid digestion come from the fact that fermentation makes probiotics. Probiotics 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.

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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.

WebMD Medical Reference Reviewed by Brunilda Nazario, MD on August 14, 2020

Sources

SOURCES:

Comprehensive Reviews in Food Science and Food Safety: “A Review on Kombucha Tea -- Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus.”

BMC Complementary and Alternative Medicine: “Hypoglycemic and antilipidemic properties of kombucha tea in alloxan-induced diabetic rats.”

Food Microbiology: “Sequence-based analysis of the bacterial and fungal compositions of multiple kombucha (tea fungus) samples.”

Colorado State University, Food Source Information: “Kombucha.”

Grand View Research: “Kombucha Market Analysis By Flavor (Original, Flavored), By Distribution Channel (Supermarkets, Health Stores, Online Stores) And Segment Forecasts To 2024.”

Memorial Sloan Kettering Cancer Center: “Kombucha.”

Food and Chemical Toxicology: “Effect of Kombucha, a fermented black tea in attenuating oxidative stress mediated tissue damage in alloxan induced diabetic rats.”

Journal of Intensive Care Medicine: “A case of kombucha tea toxicity.”

Morbidity and Mortality Weekly Report: “Unexplained Severe Illness Possibly Associated with Consumption of Kombucha Tea -- Iowa, 1995.”

Journal of General Internal Medicine: “Probable gastrointestinal toxicity of Kombucha tea: is this beverage healthy or harmful?”

Medical Journal of Australia: “Lead poisoning from drinking Kombucha tea brewed in a ceramic pot.”

Consumer Reports: “Does kombucha tea have any health benefits?”

Food Technology and Biotechnology: “Antioxidant and Antibacterial Activity of the Beverage Obtained by Fermentation of Sweetened Lemon Balm (Melissa officinalis L.) Tea with Symbiotic Consortium of Bacteria and Yeasts.”

SpringerPlus: “Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.”

Mayo Clinic: “What is kombucha tea? Does it have any health benefits?”

Clinical Gastroenterology and Hepatology: “A Gastroenterologist’s Guide to Probiotics.”

European Journal of Clinical Nutrition: “In vivo antioxidant effect of green and black tea in man.”

Harvard Health: “Understanding Antioxidants.”

American Journal of Clinical Nutrition: “Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans.”

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