Our diet has different types of saturated fat (SFA), the major ones being lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0). There is already strong evidence that replacing total SFA with unsaturated fat has been associated with lower disease risk. However, little is known about associations between individual SFA intake and coronary heart disease (CHD) risk in free-living populations. Recently, Harvard and Unilever scientists have researched the role of individual SFA on CHD risk, using data from two US population studies; the Nurses’ Health Study (73,147 women) and the Health Professionals Follow-up Study (42,635 men).
What did the study investigate?
Dietary fat intake was assessed at baseline and updated every 2 to 4 years. During 20 to 26 years of follow up, 7,035 CHD cases were documented. Total SFA intake was between 9 and 11% of total energy intake (%En). The largest contributors were palmitic acid (5.7%En), stearic acid (2.6%En), myristic acid (~0.8%En), lauric acid (~0.2%En), and the sum of smaller SFA C4:0-C10:0 (~0.5%En). Individual SFAs in the diet were highly correlated with each other. CHD risk was significantly lower when total SFA was replaced by polyunsaturated fat (PUFA), by monounsaturated fat (MUFA), by whole-grain carbohydrates, or by plant proteins. Higher intakes of lauric acid, myristic acid, palmitic acid, and stearic acid were each associated with an increased risk of CHD.
What did the investigators find out?
Heart disease risk was significantly reduced when replacing palmitic acid (but not the other saturated fats) with polyunsaturated fat, monounsaturated fat, whole-grain carbohydrates, or plant proteins.
What is the key message?
Because foods usually contain a combination of different saturated fats, dietary recommendations should remain to focus on replacing total saturated fat with unsaturated fats for the prevention of heart disease.
To read the study and for CPD points, please click here.