> Cancer: Breast (11), Andrologic (10), Lymphoma (3)
> Tumor: Neck (6), Breast (1), Colon (1)
So a nontrivial number of people reported cancer as a side effect of water fasting.
I suppose you'd probably want to review the standard correlation-does-not-equal-causation fallacy, but still.
> Table 1 describes chief complaint categories as total counts and as a percentage of total visits. A patient could have had more than one chief complaint per visit. Quality of life, including prevention and fatigue, was the primary reason patients visited TNHC (n = 384, 50%). Other major chief complaint categories included the cardiovascular (n = 193, 25.1%), musculoskeletal (n = 147, 19.1%), gastrointestinal (n = 122, 15.9%), and endocrine (n = 107, 13.9%) systems. Following prevention (n = 358, 46.7%), hypertension (n = 152, 19.7%) was the largest chief complaint category.
Reporting each and every condition, however unlikely to be caused by the subject of study, is a necessary part of a study into adverse effects. And for good reason, because it allows later research into surprising causal links, by evaluating mere correlations from different studies.
It doesn't mean the participant thought the adverse effect had anything to do with fasting.