I reckon I am late to the party on this topic.
Being old enough to know that I ain't got to say how old I am, I have used (or eaten food cooked in) cast iron all my life. No ill effects whatsoever. Matter of fact, I am on no medications for any type of malady (much to my doctor's surprise). Is it the result of using cast iron? Probably not.
Cast iron is, and has been, my preferred cookware. Properly cared for, it can last for several lifetimes.