I don’t mean to be argumentative but this is a logical fallacy called “appeal to tradition” where something is argued to be correct because it has been historically accepted.

For example, your great grandparents could have had a diet heavy in saturated fats (bacon, etc) and died prematurely from cardiovascular disease, albeit not before they had children. So just because they recognized it as food doesn’t mean it’s a healthy choice for people seeking a healthy, long life.