Cholesterol is a frequently discussed topic. So, is cholesterol 'good or bad', and should we be 'treated for it?' But what is it? Cholesterol is a 'steroid alcohol' and is found in most body tissues. Cholesterol and its derivatives are important constituents of cell membranes and precursors of other steroid compounds. We ingest some cholesterol from fatty foods but the vast majority of all the cholesterol in our bodies is synthesized from food. The body then uses cholesterol in a number of ways to maintain health.