I personally drink very little milk generally but do enjoy plenty of fermented milk. As it turns out that happens to be an excellent choice.
The knowledge problem is the continuing recycling of dietary 'truths' put out by capitalized food suppliers who have generally been seriously liberal with any science available and often even stooping to pure scientific fraud. This has created a situation in which everything must be challenged again and again. We are fortunately or unfortunately living through this process.
We have all made mistakes in our choices because of industry barking. The most egregious is the excessive use of sugar in almost every type of processed food. Of course many of those 'foods' would be unpalatable then and perhaps they should be.
The most important shift we can all make is to good quality vegetable staples. The difficulty there is that it takes a lot of effort to master best practice. I only recently learned to love eggplant. That has to be true for a lot of our foods.
I also expect that we will soon see nutrient rich vegetables been put out as a clear competitive advantage. A little sea water does that trick wonderfully for green house growers. That will eliminate my only reservation there.