[kmmlng]

This stuff is all about risk. If two people add their personal experiences, we have two data points. What are we supposed to do with that? It's not enough to quantify risk.

You can do everything wrong and be completely fine or you can do a single thing wrong and suffer the consequences immediately. Those are the two extremes and then there will be a bunch of data points in between those extremes. What you want to pay attention to are averages. How likely is it that I suffer negative consequences from this? If I do, what is the magnitude of the negative effect going to be on average?

[kjkjadksj]

And thats exactly the sort of analysis that has been performed to indicate no significant causal relationship here.