In recent years, quite a few reports have been published of the results based on the statistical information processing. For example, a study establishes that the use of a certain remedy (some food, drink, nutritional supplement, drug, treatment method, etc.) reduces (or increases) the value of some output parameter by 20 ... 30 ... 40%. The output parameter can be the frequency of onset of the analyzed disease, the frequency of its successful cure, etc. Based on this finding the conclusion is made that the studied factor significantly influences the output parameter. How trustable can such a conclusion be?
For further details see, please,
https://www.researchgate.net/publication/358965280_How_Reliable_Are_Causal_Inferences_Produced_by_Statistical_Processing_Methods_in_Regards_with_Nobel_Prize_in_Economics_2021_-for_discussion
Preprint О Достоверности Определения Причинно-Следственной Связи Мето...
Всё зависит от конкретного исследования: иногда можно доверять, иногда нет, но даже вызывающее доверие исследование должно быть подтверждено независимыми исследованиями.
usually the causal response is defined when the presence of a object creates a response on the output and the abscence of the chemical reduces the response, this is called on marketing A/B testing. the test simply concludes if the variable of causality is significative on the effect or response on the output.
The attached paper can be of use to evaluate the trustability of such studies...