Abstract 17324: Associations Between Individual Saturated Fatty Acid Intake and Risk of Coronary Heart Disease Among American Men and Women

Abstract

Dietary intervention studies report neutral effects of stearic acid (18:0) on blood lipids, compared with lauric acid (12:0), myristic acid (14:0) and palmitic acid (16:0). Evidence from observational studies on the associations between intakes of individual saturated fatty acids (SFAs) and risk of CHD is scarce. We prospectively followed 72,102 women in the Nurses’ Health Study (1984-2010) and 42,874 men in the Health Professionals Follow-Up Study (1986-2010) who were free of diabetes, cardiovascular disease, and cancer at baseline. Diet was assessed by validated food-frequency questionnaire and updated every 4 years. Baseline percentages of energy from total and major 4 subgroups (4:0-10:0, 12:0-14:0, 16:0, and 18:0) of even-chain SFA, were 11.8%, 0.6%, 1.3%, 6.6%, and 3.3% for women, and 10.8%, 0.5%, 1.1%, 6.1%, and 3.1% for men. Spearman correlations among baseline individual SFA intakes ranged from 0.43 (between 4:0-10:0 group and 18:0 in both cohorts) to 0.92 (between 16:0 and 18:0 in women). We generated 18:0 residual by regressing 18:0 on intakes of other SFAs. During 2.6 million person-years of follow-up, 6,843 incident CHD cases were documented. In the multivariate model, intakes of 4:0-10:0, 12:0-14:0, and 16:0, but not 18:0, were positively associated with risk of CHD (P<0.05). After further adjusting for dietary factors, hazard ratios (95% confidence interval, HR[95%CI]) of CHD per 1% energy increase were 1.10 (0.98, 1.22; P=0.10) for 4:0-10:0, 1.11 (1.03, 1.18; P=0.003) for 12:0-14:0, 1.09 (1.04, 1.13; P<0.001) for 16:0, and 0.98 (0.94, 1.01; P=0.22) for 18:0. The HR per 0.2 increase in the ratio of polyunsaturated fat (PUFA) to SFA was 0.93 (0.90, 0.96; P<0.001). The HRs of CHD risk per 1% of energy PUFA replacing SFA were 0.92(0.85,0.99; P=0.03) for 12:0-14:0 and 0.91(0.87,0.95;P<0.001) for 16:0; but PUFA replacing 4:0-10:0 or 18:0 were not associated with CHD risk: HRs were 0.98(0.86,1.11; P=0.74) and 0.97(0.93,1.01; P=0.19), respectively. Our findings indicate that while 12:0-16:0 were associated with increased CHD risk, short-to-medium-chain SFA and 18:0 were not. However, our results need to be interpreted with caution because saturated fatty acids share common food sources and are highly correlated.