I too suffered from high cholesterol and elected to go the 'non-drug/change my diet/lots of exercise' route. I have a normal BMI, no history of heart disease in my family, exercised regularly (4000 plus km per year) and had a reasonable diet (olive oil not butter, fish, white meat, high fibre, lots of veggies etc.)
Then I had my heart attack. That was 9 months ago, now I am back riding. However I can forget attacking hills or jumping to the next group etc. That sends my HR over the limit.
So what did I learn? I should have dealt with my high cholesterol level as soon as it was identified and forgotten the "I'm so healthy I don't need medication" attitude. (80% of your cholesterol is produced by your liver) I should have gotten a stress test even though my GP said "you stress yourself everytime you are on your bike, if there were any problems they would have shown up by now" NOT.
Now I am on the usual post cardiac chemical soup. And yes, I am on a max dose of a statin, and contrary to the paranoid internet info, I am not suffereing muscle pain and my liver functions are all normal. And my cholesterol is way down into the target zone for a high risk person.
The days of blowing people off on the hills are long gone, now I watch the same guys I used to thrash, recede into the distance as I listen to the incessant beeping of my HRM.
Take my advice, deal with the symptoms, don't wait for the heart attack and subsequent heart damage to make you do something. Going from the first guy over the hill to the last guy is the pits. Yeah, well I was probably riding with too much type A personallity/testosterone for my age (59) anyways.