There has been much controversy concerning the value of efforts to reduce blood cholesterol levels. In this contribution, the risks and benefits of interventions are discussed. Lowering cholesterol level by drugs is not recommended except in a small minority of subjects at very high risk of coronary heart disease (CHD), since it causes an excess of non-CHD deaths. Dietary intervention, by contrast, is safe. However, for it to be effective it must be sufficiently vigorous to achieve a drop in blood cholesterol of at least 6%, though considerably more is preferable. This action should be part of a more general effort aimed at the prevention of all Western diseases based on changes in lifestyle.