The first report of serious harm associated with the consumption of kombucha tea appeared in the Morbidity and Mortality Weekly Report, the journal of the US government's Center for Disease Control and Prevention (CDC). It discussed two cases of severe illness associated with the consumption of kombucha tea in a rural town in northwest Iowa.

During April of 1995, two cases of severe illness occurred within a week in two women who had both been drinking the same strain of kombucha daily for approximately two months. After a few days, a 59-year-old woman died. The other woman had a severe illness, but recovered. As a result, on April 10, 1995 the Iowa Department of Public Health recommended that people refrain from drinking kombucha until the role of the tea in these two cases of illness had been evaluated fully.

The first woman had a strange and ill-defined sickness. On April 1, a neighbor found her friend unconscious in her home and transported her to the local hospital. On arrival in the emergency department, respiratory therapy was initiated with oxygen. Analysis of her arterial blood indicated "severe metabolic acidosis." In other words, the pH or acidity level of her blood was 6.9 (normal is 7.37-7.43-the lower the number, the more acidic the blood). The woman also had elevated levels of lactic acid which, coincidentally or not, is also found in kombucha tea.

What made the case complicated is that this woman also took medications for hypertension, anemia, and mild renal insufficiency. Soon after admission, she suffered cardiac arrest and although she was resuscitated, her condition continued to deteriorate. She died on April 3. It turned out that for the previous two months she had been drinking 4 oz. of kombucha tea per day, from a culture that had spread on a literally hand-to-hand basis to over 115 people in this one Midwestern town alone.

I doubt if many people would have believed there to be a connection between kombucha consumption and this woman's fatal condition had it not been for the fact that exactly one week later, on April 10, a previously healthy 48-year-old woman was also transported by ambulance to the same emergency room where the previous woman had died. On admission, the second patient was already in respiratory distress. Analysis of her arterial blood samples again indicated severe metabolic acidosis; the degree of acidity was even greater than in patient number one, with a blood pH of 6.7. She also had elevated levels of lactic acid and also suffered cardiac arrest. But, luckily, she was resuscitated and stabilized. She was discharged on April 13, 1995.

Government scientists tried, unsuccessfully, to figure out what exactly happened to these women. It is unlikely that the mere fact that they were drinking a rather acidic drink every day led to this excess acidity in the blood. Kombucha has a pH of between 2.5 and 4.5 (Stamets 1995) But cranberry juice, which no one accuses of doing harm, has an even lower pH (between 2.3 and 2.52, according to the FDA). So how does drinking an acidic drink translate into dangerously low blood pH or a build up of lactic acid?

So probably the answer lies elsewhere. Both women were using a home brewed form of kombucha, derived from the same parent mushroom. But, according to the goverment, "at least 115 additional persons in the town had used or were using mushrooms from the same source as for the two ill women, but no other cases of unexplained acute illness were reported among these persons" (CDC 1995). Remaining samples of the beverage were carefully analyzed, and there were no known human pathogens or toxins in the brew. Perhaps some weird bacteria got into the mix of these two particular women and infected them with a still undiagnosed disease.

ANOTHER CASE

My inclination would therefore be to dismiss this CDC report as an anomaly, and hardly the basis to refrain from an otherwise healthful beverage Then, in June 2009, came a report from Los Angeles of a similar disease in a patient taking kombucha tea.

The lead author was Alison Sunghee Kole, MD, and three coauthors at Cedars-Sinai Medical Center in Los Angeles. It was published in the Journal of Intensive Care Medicine.

The authors wrote about a 22 year old man, newly diagnosed with HIV, who became short of breath and feverish (103º F) within 12 hours of drinking some kombucha tea that he had bought in a West Hollywood health food store. He subsequently became "combative and confused," and required both sedation and intubation for his breathing. The man also had a high lactic acid level. The authors conclude:

"While kombucha tea is considered a healthy elixir, the limited evidence currently available raises considerable concern that it may pose serious health risks. Consumption of this tea should be discouraged, as it may be associated with life-threatening lactic acidosis" (SungHee Kole 2009).

What I found extraordinary is that in this case, according to an email I received from Dr. SungHee Kole, the patient did not mix up some strange brew of bacteria and yeast to create his kombucha but bought it at a West Hollywood, Calif., health food store. I called the store in question and they confirmed that they sell a full line of kombucha products. I have not, however, been able to confirm the exact brand that this young man actually consumed. But I take Dr. Alison SungHee Kole seriously.

But what about the many alleged health benefits of kombucha? There is, for example, an article from India stating that kombucha "has potent antioxidant and immunomodulatory properties" (Dipti 2003) and protects the liver against toxicity (Murugesan 2009). But I am unaware of any credible data linking kombucha consumption to the prevention of either recurrences or metastases. (PubMed yields just two articles on the topic of kombucha and cancer, both of them negative.) This is a poor basis on which to make health decisions.

I for one might have dismissed the earlier reports of severe toxicity as an aberration, perhaps the result of contamination of some poorly made home brew. But the occurrence of similar symptoms in a patient half way across the country-and this time from a commercial brand-should give everyone pause.

Reluctantly, therefore, I have stopped drinking kombucha tea and will seek other, less problematic elixirs. For now, I am back to drinking Chinese tea (Camilla sinensis). There is about 100 times as much research on tea, especially green tea, as there is on kombucha. In addition, the cost of Chinese tea is about 4¢ per teapot compared to the $4 or so that I forked over for each bottle of kombucha.

--Ralph W. Moss, Ph.D.

References:

Centers for Disease Control and Prevention (CDC). Unexplained severe illness possibly associated with consumption of Kombucha tea--Iowa, 1995. MMWR Morb Mortal Wkly Rep. 1995;44:892-3, 899-900.

Dipti P, et al. Lead induced oxidative stress: beneficial effects of Kombucha tea. Biomed Environ Sci. 2003 Sep;16:276-282.

Murugesan GS, Sathishkumar M, Jayabalan R, Binupriya AR, Swaminathan K,Yun SE. Hepatoprotective and curative properties of Kombucha tea against carbon tetrachloride-induced toxicity. J Microbiol Biotechnol. 2009;19:397-402.

SungHee Kole A, Jones HD, Christensen R, Gladstein J. A case of Kombucha tea toxicity. J Intensive Care Med. 2009;24:205-207.

To check out my latest Current Topic report, 'German New Medicine®'-Hope or Hoax, click here.