Kombucha is a tea containing several species of fermented yeast and bacteria. It is made by adding a "baby" starter colony taken from an exisitng "mother" colony to a mixture of tea and sugar. It is then allowed to ferment at room temperature for 7-14 days, growing a thick layer of a symbiotic colony of bacteria and yeast that then creates a fizzy, vinegary liquid full of B vitamins and other chemical compounds.
"Health benefits attributed to Kombucha tea include stimulating the immune system, preventing cancer, and improving digestion and liver function," writes Brent A. Bauer, M.D. from the Mayo Clinic.
It first gained popularity in the early '90s with health food enthusiasts and those with H.I.V. as it was thought to benefit compromised immune systems and increase T-cell counts. But after a few individuals, who drank kombucha on a regular basis, died from from severe metabolic acidosis (excessive acid buildup in the body), the CDC issued a report linking the drink to those deaths, thus curbing the craze.
Smaller companies producing the drink have sprung up over the past few years, and after retailers like Whole Foods began distributing it nationally in 2004, other beverage giants like Red Bull and Honest Tea have jumped on the bandwagon and are putting their own versions on the market.
Dr. Daphne Miller, a family practitioner and professor of nutrition and integrative medicine at the University of California, San Francisco, told Wollan, "It’s become incredibly trendy lately in the 20-to-30-something, foodie, intelligentsia set. Kombucha is like their Coca-Cola." And Tamara Palmer, a San Francisco food blogger, stated in the NYT article that kombucha was on its way to becoming "the new bacon."
Though it may have its alleged health benefits, many health professionals still say it should be consumed with caution, especially the home brewed concoctions.
According to Dr. Bauer,
"...there are reports of adverse effects such as stomach upset and allergic reactions. More worrying are the reports of toxic reactions and metabolic acidosis. In addition, the Food and Drug Administration cautions that the risk of contamination is high because Kombucha tea is often brewed in homes under nonsterile conditions. Lead poisoning also may be a risk if ceramic pots are used for brewing — the acids in the tea may leach lead from the ceramic glaze."
And health guru Dr. Andrew Weil isn't a fan of it either. He writes on his website:
"I am also concerned about the possibility of contamination in home-brewed kombucha. Some batches contain aspergillus, a toxin-producing fungus. This would be a significant risk for individuals with compromised immune systems, such as those with AIDS or in chemotherapy for cancer. There have been reports in the medical literature of adverse reactions, including nausea, vomiting and headaches, in people drinking more than four ounces of kombucha tea daily.
In summary, I know of no health benefits to be gained by drinking kombucha tea."
The bottom line: As with anything that has no proven medical benefits but linked to adverse health effects, approach with caution. If someone is curious about trying the kombucha, starting out with a brand sold at the store may be a safer bet than buying it from a random home brewer. And it's just common sense to ask a health professional first before going to headfirst into subscribing to daily doses of it, especially if one has a compromised immune system or is pregnant or elderly.