Contrary to the bad reputation cholesterol has received in the media lately, we DO need it. Without cholesterol, we would not have hormones such as estrogen or testosterone in our bodies. Cholesterol gives our cells the strength they need to maintain their shape. Cholesterol is also used in the body to provide the myelin lining to our nerve fibers. This helps our nerves to relay signals more rapidly and efficiently.
copy from : cholesterol.about.com