Brainwashing is spot-on.
Mainstream Doctors believe that there is no or little association between diet and disease......the cause is either a virus or bacterium or genes. They also receive very little training in nutrition: about 4 to 6 weeks in a 6 year training programme.
The American Dietetic Association (ADA) are largely responsible for this ignorance and are currently trying to monopolize the approval of credentials in their interests.
Just think of the billions of $$ that could be saved by correcting ones lifestyle and especially in dietary choices.