Total cholesterol and all-cause mortality by sex and age: a prospective cohort study among 12.8 million adults

There is a disconnect between the advice we are currently being given
Total cholesterol levels less than 200 milligrams per deciliter (mg/dL) 5.172mmol/L are considered desirable for adults. A reading between 200 and 239 mg/dL (6.18mmol/L) is considered borderline high and a reading of 240 mg/dL ( 6.206mmol/L) and above is considered high.

and what is actually reported in recent research
The NCEP experts classified TC levels into 3 categories: <200, 200239, and ≥240 mg/dL, as desirable, borderline high, and high levels, respectively, mainly based on the association between TC and IHD21.
In the current study, however, TC levels of 210249 mg/dL (5.431- 6.18mmol/L) and approximately 200240 mg/dL were associated with the lowest mortality in the categorical and spline analyses, respectively.
Our study suggested that the optimal ranges for overall survival are higher than that those for IHD.
Cholesterol levels might be a marker of general health, rather than a marker specific for CVD