Food is like religion for many. I don’t mean they worship it. I mean they believe things about it with no evidence and debate endlessly, claiming truth about unsubstantiated claims that they believe substantiated.
In principle you can measure and experiment with it, but the number of variables is so great that experiments alter and reverse conclusions soon after.
Someone told me something compelling on the issue. He said decades ago he heard a new claim about food. It was surprising, so he decided to wait for further confirmation. In particular, he said he would only act on new claims about food, no matter how scientific their basis seemed, if they endured at least five years.
He has seen no claim stand five years without being reversed since then.
Meanwhile, outside our culture of the-latest-science-on-food!, most cultures are healthier than ours and they become less healthy as we influence them.
I’m sticking with old practices over new theory and experiment.