Mold hypothesis

The mold hypothesis is the hypothesis that mold exposure is implicated in the onset of ME/CFS, or in perpetuating or worsening it. It came to prominence by discovery of toxic mold in the clusters of "mystery malady" that had baffled the CDC into creating the Chronic fatigue Syndrome.

Evidence
The evidence was found by school authorities and testing by mold remediation companies after CFS researchers failed to locate literature and proper testing for toxic mold, and had prematurely concluded that the clusters of illness must be solely due to viral causes.

In 2013 a study of 112 CFS patients found 93% were positive for at least one mycotoxin. In the study, this was compared to a previously tested group of healthy controls without a history of exposure to water damaged buildings or a moldy environment, where no positive cases were found. The study was criticized in letters to the journal for the choice of the comparison group, because specifically choosing a comparison group without a history of mold exposure could bias the study towards finding more mycotoxins in the CFS group. The authors replied saying that their study was just a clinical observation study, and that it was useful for hypothesis generation for future studies.

A 2019 study looked at 236 ME/CFS patients that had a prior history of mold exposure, and found evidence of at least one mycotoxin in 92.4% of the patients. The ME Association noted various limitations to the study, including the lack of a control group, the selection of patients on the basis of past exposure to mold, which would lead to a higher detection rate of mycotoxins, and the lack of knowledge about mold prevalence in the general population. The authors of the study stated it was preliminary.

Research
In 2019 Professor Ron Davis said that his group was considering conducting experiments to explore the possible role of mold in ME/CFS, and suggested it needed to be explored. However he noted difficulties with complexity and funding.

Notable studies

 * 2013, Detection of mycotoxins in patients with chronic fatigue syndrome (Full Text)

Learn more

 * Study Suggests Mold Exposure Can Cause Severe Effects in Chronic Fatigue Syndrome (ME/CFS) by Cort Johnson in Health Rising