We didn't do that; instead, we let threw out all of that knowledge, the good and the bad, and we have 100 million sick people in the US and over a billion around the world.
I'm not sure what you expected scientists to do. None of the "traditional wisdom" was confirmed as true, it all had to be tested and was considered suspect until such testing had taken place.
On top of that, traditional diets had shortcomings. It's hard to produce enough calories for today's population to survive, without a larger proportion of those calories coming from grains.
Faced with this change in the food landscape, and with faith in traditional wisdoms rightly shaken, nutritionists have been basing their advice on reasoning from first principles, and preliminary results. They got it wrong badly. But at least we were on the path to a better understanding of nutrition. It's been too slow, and nutritionists were not skeptical enough of preliminary results, but lucky us, these are problems science knows how to fix.
I'm not sure what you expected scientists to do. None of the "traditional wisdom" was confirmed as true, it all had to be tested and was considered suspect until such testing had taken place.
On top of that, traditional diets had shortcomings. It's hard to produce enough calories for today's population to survive, without a larger proportion of those calories coming from grains.
Faced with this change in the food landscape, and with faith in traditional wisdoms rightly shaken, nutritionists have been basing their advice on reasoning from first principles, and preliminary results. They got it wrong badly. But at least we were on the path to a better understanding of nutrition. It's been too slow, and nutritionists were not skeptical enough of preliminary results, but lucky us, these are problems science knows how to fix.