I have always had higher than normal Cholesterol. When I was being diagnosed for PMR at Mayo they found I had blockage in the carotid. They did the testing for FH. The Mayo Dr. told me you cant fix FH with diet. That said I do believe the saying you are what you eat. I had tried to keep numbers down with a keto style diet that worked somewhat but to much fat for me. I was just doing my best with no sugars and breads. Could I have done better. Sure.. Maybe all plant diet. Obviously what I was doing was not working. 100% blocked in the right and 70% in the left. I have told my kids to get tested for FH. but its not a run of the mill test apparently. Unfortunately what we eat and our genetics are 2 tough things to get past.