A natural butterfat that elicits clinically significant lowering of total-and LDL-cholesterol when added to the diet of normal men: a novel route todecreasing cardiovascular risk in human populations?

Current US guidelines recommend that less than 30% of dietary energy (en%) in adults should derive from total fats, in part to limit excessive intake of saturated fats, which is linked to atherosclerosis, obesity and some can cers. Dairy foods are a major source of saturated fats, so such guidelines effectively advocate decreased consumption of dairy products to 2-4 serving s daily. Milk containing increased unsaturated fatty acids has been produce d by feeding cows with a protected feed supplement rich in oleic acid. Feed ing of butterfat derived from this milk elicited decreased blood LDL-C in t wo of three trials. To resolve ongoing uncertainty concerning the efficacy of butterfat per se, we have investigated its blood lipid-lowering potentia l in 20 healthy male subjects using a double-blind, randomised, interventio n trial. During this residential trial, all foods and beverages were provid ed during two intervention periods, comprising 3 weeks of high unsaturated 'modified' vs. 3 weeks of saturated 'control' butter feeding separated by a 4-week washout period. Diets were of typical composition of 39 en% fat (20 en% butterfat), 48 en% CHO, 13 en% protein. There were significant decreas es in both total (p <0.05, -7.9%) and LDL-C (p <0.01, -9.5%) during feeding of modified butter, but no significant changes in a range of other risk fa ctors including HDL-C, TG, or fasting glucose (p >0.05). Subjects were main tained in energy balance with no significant change in body weight during i nterventions; butterfat composition alone differed between treatments. Thus , clinically significant improvement in cardiovascular risk can be achieved by moderate changes in dietary fatty acid profile achieved through a commo n and well-accepted food source, butterfat.