This is a fatty substance belonging to the family of sterols and found mostly in animal tissues. Cholesterol circulates in our blood and is an essential component of cell membranes some hormones . Most of it is made by the liver but some of it is taken up from the foods we eat. Animal fats contain about 0.1- 0.3% cholesterol while vegetable fats only have a trace at about 0.0003%.

Medical authorities in EU recommend a desirable blood cholesterol level of 5 milli moles/L (195 mg/dL). When too much is present and especially oxidised cholesterol which is sticky, it tends to adhere to the artery walls and cause blockages, often leading to heart attacks and strokes. There are two main types of cholesterol, HDL-C which is good and LDL-C, accounting for the greatest part, which is bad. Broadly speaking, saturated and trans fats increase blood cholesterol levels, while monounsaturated fats are neutral and polyunsaturated ones reduce it. In the USA, FDA allows foods to be labelled "cholesterol free" if hey contains less than 2 milligrams cholesterol and 2 grams or less saturated fat, per serving. The nutritional aspects of oils and fats are still controversial and powerful lobbies in the industry are spreading much misinformation. Lay people should only be guided by advice from their own doctors and from official medical authorities.