Dr. Ornish and Medicare: Reversing heart disease with comprehensive lifestyle changes
 

Dr. Ornish has conducted extensive clinical research for over 30 years and has demonstrated that even severe coronary heart disease (clogged arteries) can be reversed with comprehensive lifestyle changes, without drugs or surgery.

The diet he recommends is a low fat vegan diet and includes many types of grains like whole wheat, barley etc.. The results were so impressive that Medicare agreed to provide coverage for his program which started sometime around 2007.

I don't think a grain free, high fat, high protein diet can make the same claim. (This assumes you don't have Celiac disease or Gluten intolerance.)