So, you want to eat a healthy diet, how do you do it? One option is to examine the nutritional information on everything find and make sure you only consume stuff with ingredients nutritionists agree is healthy. This approach gives the impression of being sciencey and rational, but you'd have a nagging feeling that there was something important missing. A diet comprised of only healthy things might be a terrible diet.
Learning to cook a bunch of traditional recipes from your culture from your grandmother is quite likely to end up being a better guide to a healthy diet that the approach above, but we wouldn't necessarily have any idea of what crucial stuff we were happily consuming.
The point is, it's easy to construct a worldview entirely out of true facts only for it to be fatally anaemic and many cultural norms and traditions contain wisdom that we only dimly comprehend.