I just got some info on the "study" referred to in this thread. Apparently it wasn't so much a study as it was a survey based on peoples' self reported eating habits. It seems like there was no control over isolating variables. So basically someone was asked how many egg yolks they ate but was not asked whether they smoked, ate excessive amounts of sugar, ate high levels of trans fats, drank excessively, etc. Sounds like a bit of a flawed study to me.