My grandmother lived to be 99 and died within 6 weeks of her hundredth birthday ... she loved bacon, egss, milk, butter, meat ... but she ate healthy (read: smaller portions) ... she didn't overdo everything and she didn't eat processed foods.
I think any study can be "swayed" by whomever is requesting, paying for, donating funds towards ... and the results assist them to "sell their product" and make millions. It's how the world works. No one wants to "back a loser" as such.
Tell the "general public" something scary and they "purchase" appropriately, as they have no *rude word* idea but want to appear to be "doing something about it" ... whatever "IT" may be.
Remember a few decades back ... apples & avo's gave you cancer! There is NO WAY I'm not eating either of them.
My doctor loves testing this and that ... I eat what I want, but like Gran, I eat healthy ... so far poor Dr can't find anything wrong with me ... Keep trying mate ... there is bound to be something eventually!!

Kit_e