For women over 50, there was increased longevity associated with higher levels of cholesterol in this study.

No-one knows if higher cholesterol causes health problems, as the information is correlational only.
It is like saying that we find higher numbers of policemen at the scene of the crime, so therefor police cause crime.

And half of people who die of CHD have normal cholesterol levels. The skeptics of the cholesterol-heart theory do not consider that there is any evidence for it that cannot perhaps be explained by other factors (cf www.thincs.org).

Val