Ldl cholesterol is most hamful when it gets oxydized.
Young people and elderly don't oxydize too much so the danger of ldl cholesterol is J shaped with most danger between 40 and 70 years old.
So the best estimation of the danger of cholesterol, according to several studies is to divide total cholesterol over Hdl cholesterol. This ratio must be under 4.95 in men and 4.44 in women.
I personnaly expect new studies to establish normal ratio in men and women according to their age.
I mean a young man whose ratio is at 4.95 is more exposed than an elderly with this same ratio.
So this problem is very serious, has to be managed by experienced doctors because both length and quality of life depend on it...