Factors affecting LDL cholesterol reduction: unsaturated fatty acids

Substantial evidence indicates that dietary saturated fatty acids, specific ally lauric, myristic and palmitic acids, raise cholesterol levels. In cont rast, stearic acid is neutral or may lower plasma low-density lipoprotein ( LDL) cholesterol when it replaces palmitic acid in the diet. A reduction in cardiovascular risk is achievable by substituting a portion of dietary sat urates with unsaturated fatty acids. However, concern remains about possibl e unhealthy effects of diets excessively high in polyunsaturated fatty acid s. Indeed, in addition to lowering plasma high-density lipoprotein (HDL) ch olesterol levels, an increased intake of linoleic acid renders plasma LDL p articles more oxidizable and potentially more atherogenic; it also might en hance carcinogenic processes. Epidemiological data clearly indicate the saf ety of diets high in oleic acid, but there is no analogous evidence for die ts rich in linoleic acid. In Israel, where part of the Jewish population co nsumes very high amounts of linoleic acid, this dietary regimen does not ap pear to protect against cardiovascular disease and other degenerative disor ders. Current dietary recommendations for the general public suggest that t otal fat should not exceed 30% of total calories (8-10% from saturates, les s than or equal to 10% from polyunsaturates, and less than or equal to 15% from monounsaturates). However, for some individuals, oleic acid intake cou ld be increased to 10% or 20% if saturated fat remained between 8% and 10% of calories, because this type of diet has been proven safe and beneficial for the cardiovascular risk profile.