These "latest studies" are actually rather old, easily over a decade old. I don't know if there were formal scientific studies conducted (I'm sure there is, I just never went looking for it), but there were multiple investigative journalists who debunked this myth. Further, unfortunately it is believed that there is an element of racism that perpetrated this urban myth. I remember back in the 90's when this urban myth was all over the news, many Chinese takeout restaurant across the US starting to put "No MSG" on their menu, but I am confident they didn't changed their ingredients, they probably thought to themselves "well if they are going to slander us, we'll just tell them whatever they want to hear."
I don't use MSG at home because we cook with a lot of herbs and spice, so we get plenty of flavor and umami as it is.