There's so much that I'd like to say about the subject, and so much what I would have wished the article to have included. The issue is usually far more complicated than looked at first glance; for example, the recommendations for beer and wine come from the unsanitary standards and the verified sickening influence of water. Alcohol kills the bacteria. Also, the beer and water of the times were usually much lighter than that of today.
Even though the people of the past have had numerous misunderstandings regarding health, I firmly believe the people of the millenia have been brighter than the people of today. There is no reason why a number of doctors and medical practisioners couldn't have come up with perfectly sensible diets and other advice through their experience and the experience of their ilk before them. Then again, there is leech.