Though Cholesterol has a bad reputation as a cause of Heart Disease it does however perform some vital functions and is produced naturally in the Liver and we cannot do entirely without it. Diet is essential to reduce the levels but even if you excluded it completely from your diet the liver would still produce cholesterol and therefore you would always have some in your blood. The level of production in the body is variable according to requirements and therefore is not at a constant measurement. Control of high levels is best done through diet and exercise. Most western diets contain animal fats, which in turn are converted by the body into cholesterol, reduction in the animal fat intake therefore helps to lower the Cholesterol levels in the blood, but these levels are not static and do fluctuate because of the natural production by the liver.