I am principally skeptic about association studies. Which is a polite way of saying that the association=causation suggestion goes against my statistician's brain. I have taken a clear position in this matter in two posts of mine. One here on Medium (https://medium.com/p/ecfe3cb04304) and one on my website. (https://www.adiphea.com/en/everything-you-read-about-red-meat-and-health-may-be-wrong/).