“Although the benefits of lowering blood cholesterol in order to protect patients from premature death caused by myocardial infarction or stroke are undisputed, national campaigns to identify high cholesterol in the community need to give serious consideration to the increasing body of evidence from epidemiological studies linking low total cholesterol to an increased risk of non-cardiac mortality. Lung cancer is the most consistent cause of non-cardiac death to be associated with low serum cholesterol levels. The incidence of cancer of the colon is also strongly correlated but no association has been found for gastric, rectal or brain cancer. The general consensus is that the risk of noncardiac death increases when total cholesterol falls to < 160 mg/dl.”
https://academic.oup.com/eurheartj/article-pdf/18/1/52/1233369/18-1-52.pdf
It is so hard to find the optimum values of everything we consume for the best outcome of good health and long life. Perhaps the best advice is the age-old admonition “Everything in Moderation.”
This is very much disputed. In fact it's down right unscientific. There is no good science that says higher total cholesterol will lead to a heart attack. Never was.