 Even if one were to believe, with the proponents of EBM, that observational studies are generally less reliable than RCTs, medicine could—fairly obviously—not do without them. There are large numbers of pressing questions that could not be addressed by an RCT for ethical, financial and other practical reasons. No-one would seriously consider testing a proposition such as “Aflatoxin causes cancer of the liver (in humans)” by an RCT. This is not merely because of the straightforward ethical issues involved in deliberately exposing humans to a potential carcinogen for the sake of medical progress. It is also because exposure to low levels of aflatoxin can take many years or even decades to produce symptoms. The ability of researchers to control food intake in a large group of experimental subjects for a very long has evident practical financial and limitations. RCTs can also not be used when researchers or patients or both cannot be blinded, and many medical interventions do require the doctor’s or the patient’s knowledge of details about the intervention.