Peanut oil reduces diet-induced atherosclerosis in cynomolgus monkeys.

Abstract

The atherogenicity of dietary peanut oil (PO) was examined in cynomolgus monkeys fed semipurified diets for 15 months. Four groups of six monkeys were fed diets containing 0.22 mg/kcal (0.1%) cholesterol and 0%, 5%, 10%, or 20% PO. An additional group was fed 2.0% cholesterol and 20% PO to serve as a literature control. Increasing the concentration of PO in the diet was associated with significant decreases in total plasma cholesterol (p < 0.05) and the total/HDL cholesterol ratio (p < 0.05) and an increase in the terminal HDL cholesterol concentration (p < 0.05). Intimal thickness and composition were determined from cross sections of the thoracic aorta and the iliac and coronary arteries. P eanut oil (PO) is reportedly atherogenic when fed to rats, 1 rabbits, 2 ' 6 and monkeys 3 despite a relatively high concentration of polyunsaturated fatty acids. However, the majority of studies addressing this issue have been complicated by diets containing PO in combination with high levels of cholesterol or sucrose or both. In experiments in rats 1 and rabbits 4 with low levels of sucrose in the diet and no added cholesterol, atherosclerotic lesions were not found in the animals fed PO. The evidence suggesting PO is inordinately atherogenic in monkeys derives from studies in which rhesus monkeys were fed 2% cholesterol.3 However, weight gain as a percentage of the initial body weight (and by inference the total calorie and cholesterol intake) of the PO group was almost double that of com oil-fed monkeys and 50% greater than that in those fed butter. Thus, lesion development appeared to reflect the total cholesterol intake. When vervet monkeys were fed diets containing no added cholesterol, the atherogenicity of PO was no greater than that of corn oil.5 These results raise the question whether the atherogenicity attributed to PO is actually a reflection of a high cholesterol intake. Specific structural characteristics have also been attributed to the arterial lesions of peanut oil-fed animals. In rabbits 6 and monkeys, 37 these lesions have been described as dense and fibrocellular with relatively little lipid when compared to lesions of animals fed butter oil or a butter fat-coconut oil mixture. In contrast to these descriptive data, biochemical determinations of collagen and elastin accumulation failed to reveal excessive concentrations of fibrous proteins in the arteries of peanut oil-fed rabbits. 8The present study was designed to address the question of PO atherogenicity and the quantitative morphology of the intimal response under carefully controlled dietary challenge. Intimal thickness and composition were measured in the arteries of cynomolgus monkeys fed for 15 months on diets containing graded amounts of PO and a level of cholesterol approximating the human experience (0.1%). An additional group was fed a PO diet containing 2% cholesterol to serve as a literature control.The results indicate that an increased PO intake is protective in terms of cholesterolemia and is associated with reduced atherogenesis when c...

Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study

“…Although one study showed that peanut oil was atherogenic when fed to rats and rabbits,21 in another study it was antiatherogenic when fed to cynomolgus monkeys; the blend of fats approximated the fatty acid composition of the average diet in the United States 2223…”

Decreased aortic early atherosclerosis and associated risk factors in hypercholesterolemic hamsters fed a high- or mid-oleic acid oil compared to a high-linoleic acid oil

“…This protective finding for a MUFA-enriched diet is not supported by one study in monkeys [7], a study in LDL receptor-null, human apolipoproteinB-overexpressing transgenic mice [43] and one study in LDL receptor-deficient mice [44]. On the other hand, the antiatherosclerotic properties of MUFA-enriched diets have been demonstrated in rabbits [45][46][47][48] and monkeys [49,50], our own previous studies in hamsters [13], and in swine [51,52]. There are several possible mechanisms derived from both in vitro and in vivo studies that might explain the beneficial effects of MUFA-containing diets as they relate to early atherosclerosis.…”