My very high cholesterol is genetic. At 10 or 11, when it was found, I went on a rigid diet. Did not lower my total chol. from 380. (HDL, btw is only 19). There was no effective medicines for 15 years after that -- when Mevacor came out. Still, that reduced my Chol. to about 300. Newer drugs get me down to about 250.
I am alive at almost 50.