Participant in a Netherlands study found that a 39 point increase in total cholesterol resulted in a 15% decrease in mortality risk. They found in their elderly participants that people with the high cholesterol could extend longevity.
Another 2008 study found that people with ALS( a disease of the motor neurone system) lived one year longer with high levels of cholesterol.
Still not convinced? The brain is only 2% of the bodies mass BUT it contains 25% Cholesterol.
Cholesterol forms membranes surrounding cells, keeps cells membrane permeable and reduces chemical reaction that can take place inside and outside the cell.