Carbohydrate restriction decreases small LDL particles, attenuates inflammation and alters mechanical properties of aortas in the cholesterol fed guinea pig

Abstract

Both dietary cholesterol (chol) and carbohydrate restriction (CR) significantly impact plasma lipids, atherogenicity of lipoproteins and inflammatory cytokines. We evaluated the effects of chol and CR on aortic cholesterol and triglycerides accumulation, plasma secretory phospholipase A2 (sPLA2) activity, aorta stiffness as well as aortic cytokine concentration in guinea pigs. Forty adult male guinea pigs (10/group) were fed either low (L) (0.04 g/100g) or high (H) (0.25g/100g) amounts of chol in combination with CR (10% total energy) or high carbohydrates (54% total energy) for 12 wks. Groups fed the high chol (control‐H and CR‐H) had higher cholesterol and triglycerides accumulated in aortas (P< 0.05) and higher sPLA2 activity than those guinea pigs in the L chol groups. CR resulted in lower concentrations of plasma small LDL subfractions (P < 0.01) and aortic cytokines and chemokynes including TNF‐α, IL6 and MPC‐1 (P < 0.01) than the high carbohydrate groups. Regarding the aorta stiffness, the control‐H and the CR‐L were stiffer than the control‐L and the CR‐H groups. These results can be interpreted as different stages of atherosclerosis development. The control‐H diet is postulated to be in the last stage of atherosclerosis, the CR‐H and the control‐L in an intermediate phase and the CR‐L at the beginning of the process. These results demonstrate that CR has a major impact on atherogenicity of lipoproteins, aorta stiffness and aortic cytokine accumulation. In addition, CR diets appeared to ameliorate the atherosclerotic potential of the high cholesterol diets.