Background:
The association between monounsaturated fat (MUFA) intake and coronary heart disease (CHD) risk remains unclear. We aimed to investigate whether MUFA from plant foods (MUFA-P) and animal foods (MUFA-A) show different associations with CHD risk in two large prospective studies of U.S. men and women.
Method:
We calculated MUFA-P and MUFA-A among 60,931 women in the Nurses’ Health Study (1990-2012), and 28,445 men in the Health Professionals Follow-Up Study (1990-2010). Diet was assessed by validated food-frequency questionnaire every 4 years. CHD incidence was self-reported and confirmed by review of medical records or death certificates.
Result:
MUFA-A (median intake: 5.8-6.1% energy) was highly correlated with saturated fat (SFA; spearman correlation [
r
] =0.81-0.83) but not polyunsaturated fat (PUFA,
r
=0.04 -0.19), whereas MUFA-P intake (median: 5.3-5.4.9% energy) was strongly correlated with PUFA(r=0.61 for both cohorts) but not SFA (
r
=0.20-0.21; All P<0.001). In multivariate models adjusted for demographic, lifestyle, and dietary factors, hazard ratios of CHD (HR, 95% confidence interval[95%CI]) from low to high total MUFA quintiles were 1 (reference), 0.92 (0.83, 1.02), 1.03 (0.93, 1.05), 0.89 (0.79,1.00). 0.95(0.873, 1.08; P
trend
=0.42). For MUFA P these were 1(reference), 0.98 (0.89, 1.07), 0.90 (0.82, 0.99), 0.85 (0.77, 0.93), and 0.86 (0.78, 0.94; P
trend
<0.001) and for MUFA-A 1(reference), 1.09 (0.99, 1.20), 1.22 (1.11, 1.35), 1.26 (1.13, 1.39), and 1.33 (1.19, 1.48; P
trend
<0.001). In the energy-density model, CHD risk was lower when MUFA-P iso-calorically replaced 1% energy from total SFA (HR [95%CI]: 0.96[0.92, 1.00]; P=0.03), with no significant changes when MUFA-A replacing SFA (HR [95%CI]: 1.01[0.95, 1.07]; P=0.76). When grouping fat intake as the sum of animal MUFA plus saturated fat and the sum of plant MUFA plus PUFA, the HR (95%CI) of CHD was 0.96 (0.95, 0.98; P<0.001) for replacing 1% energy from the former with the latter.
Conclusion:
Because MUFA compositions of animal and plant origins are largely similar, our data suggested other components in plant and animal foods may lead to the observed different associations of MUFA-P and MUFA-A with CHD risk. These findings provided a possible explanation on current controversies regarding MUFA intake and CHD risk, and further support health benefit of MUFA intake.
Saturated Fat Consumption and Risk of Coronary Heart Disease and Ischemic Stroke: A Science Update
