Exactly the opposite of the scientific approach, which is to propose a testable hypothesis, then set about testing validity. If the initial work is flawed by bias, then peers reviewing the work will be only too happy to point out the errors and provide the reproducible evidence to refute the claims.

Alties assume that natural is better and no evidence (belladonna, botulinum, digitalis, willow bark, etc.) to the contrary could convince them that many natural compounds have both benefit and harm, and some (tetrodatoxin) only have harm.