Abstract 593: High-Monounsaturated Fat Mediterranean-Type Diet Reduces Foamy Monocyte Formation and Atherosclerosis in Ldlr-/- Mice on High-Cholesterol Diet

A large randomized clinical trial (PREDIMED) showed that adding “healthy monounsaturated fat (MUF)” to Mediterranean diet (MedD) by supplementation with extra virgin olive oil or nuts led to a reduction in atherosclerotic cardiovascular events, but the mechanisms remain incompletely understood. Hyperlipidemia, a major risk factor for atherosclerosis, may induce lipid accumulation in circulating monocytes, leading to formation of foamy monocytes (FMs), which contribute to atherosclerosis. We hypothesize that high-MUF MedD reduces FM formation and therefore inhibits atherogenesis associated with hyperlipidemia. To test this, LDLR-/- mice were fed western-type high-saturated fat, high-cholesterol diet (WD) (21% milkfat containing 13.3% saturated fat and 5.9% MUF; 0.2% cholesterol), high-MUF MedD with high cholesterol (HC-MedD, 21% fat [from extra-virgin olive oil, walnuts, almonds, and hazelnuts] containing 2.6% saturated fat and 13.4% MUF; 0.2% cholesterol), or normal diet (ND, control). At 3 months, mice on HC-MedD had similar body weight gain but significantly lower liver/body weight index compared to mice on WD. Plasma triglyceride levels were significantly lower in mice on HC-MedD (318 ± 31 mg/dL, n=13) than on WD (769 ± 60 mg/dL, n=9, P