Celebrities are powerful role models and are important to consumers concerned with their health because of the perception that famous people have access to the best health practices and medical care. The public looks to celebrities for hope and inspiration as they struggle with their own health issues and fight disease. However the health practices that celebrities promote are often questionable and misleading.

One currently popular folk remedy, kombucha tea, is part of the dietary regimens of multiple Hollywood actresses and entertainers including Gwyneth Paltrow, Kirsten Dunst, Lindsay Lohan, Madonna, Halle Berry, Meg Ryan, Anna Paquin, Cher, Barbara Streisand, Alec Baldwin and Susan Sarandon. The claims for its medicinal value are as far reaching as they are implausible and include aging, anorexia, arthritis, atherosclerosis, cancer, constipation, diabetes, gallbladder disease, gout, hemorrhoids, hair growth and color restoration, headache, hypertension, HIV, immune boosting, indigestion, increased vitality, treatment of alcohol and coffee addictions, and wrinkle reduction.

Kombucha is a form of black tea and sugar that is fermented using a combination of bacterial and fungal cultures that form a “mushroom” on top of the fermentation vessel. It originated in China thousands of years ago, eventually spreading to Europe, and is today becoming increasingly popular, through celebrity use and endorsement, in the U.S. and U.K. Many home brew recipes for making kombucha may be found on the Internet but it is also manufactured and sold by companies such as Synergy Drinks.

We conducted a literature review of kombucha at www.pubmed.gov and found 40 articles on kombucha tea. Many of these studies originated in China or India and consisted of testing the effects of kombucha tea on rats or mice; a few papers tested effects on human cancer cells in vitro. Some beneficial effects were seen but one study concluded that “Comparable effects and mechanisms in humans remain uncertain, as do health safety issues, because serious health problems and fatalities have been reported and attributed to drinking kombucha.”

Most of the reports of human consumption of kombucha tea are case reports of toxicity, in some cases, life-threatening. The greatest danger from kombucha seems to arise in “home brew” versions that have become contaminated because of improper preparation and/or when kombucha interacts with alcohol or prescription drugs.

Observed adverse effects of kombucha consumption include hepatitis, xerostomia, dizziness, nausea, vomiting, headache, shortness of breath, restless legs, abdominal pain, hypotension, and tachycardia. In most cases, patients fully recovered after discontinuation of kombucha and symptomatic treatment.  However there are case reports of serious and sometimes fatal cases of hepatic dysfunction and lactic acidosis.

In addition to oral ingestion, skin application of kombucha is also used as a topical analgesic. Such use has resulted in cutaneous anthrax infections from kombucha stored in unhygienic conditions; such conditions make kombucha preparations a potential medium for the growth of pathogenic microorganisms.

Because folk medicines, herbal remedies and dietary supplements, including Kombucha tea, are not considered foods or drugs, they are not routinely evaluated by the U.S. Department of Agriculture or the U.S. Food and Drug Administration (FDA). According to the U.S. Centers for Disease Control and Prevention (CDC), drinking this tea in quantities typically consumed (approximately 4 oz daily) may not cause adverse effects in healthy persons; however, the potential health risks are unknown for those with preexisting health problems or those who drink excessive quantities of the tea.

Recently, Whole Foods removed kombucha drinks from its store shelves because they can contain alcohol as a product of the fermentation process. This fact was used as a possible explanation for why actress Lindsay Lohan’s alcohol-monitoring (SCRAM) bracelet was activated even though she asserted compliance with court orders not to drink alcoholic beverages.

Michele Berman is a pediatrician who blogs at Celebrity Diagnosis and at MedPage Today Blogs, where this post originally appeared.

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