Dietary Fat Quality Plays a Sex‐Specific Role in Attenuating Metabolic Risk Factors in Aging CD‐1 Mice

Abstract

Diet quality (e.g., dietary fat type) and aging play an important role in the development of type 2 diabetes, however, is not known if long‐term consumption of diets with differing fatty acid profiles can modulate metabolic risk factors in an aging population. Accordingly, we aimed to examine how different sources of fatty acids added to a western‐style diet might improve metabolic risk factors during aging. Sixty male and female outbred CD‐1 mice (n = 10/group) were fed isoenergetic high‐fat diets (40% kcal fat) containing either (1) American diet fat blend (100%) (Control, CON; reflecting the average fatty acid profile consumed in the United States linked to dysmetabolism and increased inflammation), (2) CON fat (70%) + 30% butter oil (BO), (3) CON fat (70%) + 30% echium oil (EO), or (4) CON fat (70%) + 30% fish oil (FO) for a total of 14 months. Standard physiological measurements and glucose homeostatic assays (i.e., intraperitoneal insulin and glucose tolerance tests) were performed at regular intervals (3, 6, 9, and 12 months of dietary intervention) and key tissues were harvested at 14 months of age. Despite CON males having a consistently lower feed intake (P < 0.001) and weight gain (P = 0.002), they exhibited a markedly reduced glucose tolerance by 9 months (P = 0.02) compared to FO (P = 0.005) and EO males (P < 0.001) which persisted through 12 months. CON males also had an increased accumulation of triacylglycerols in the liver compared to EO, BO, and FO males at 14 months (P < 0.001). Although BO males showed transiently reduced glucose tolerance at 9 months (P = 0.02) compared to FO (P = 0.009) and EO males (P = 0.001), this phenotype dissipated by 12 months. EO males exhibited a trend of overall improved insulin sensitivity compared to BO males (P = 0.05). While females displayed no differences in feed intake, weight gain, glucose tolerance, or insulin sensitivity among the diet groups at 3, 6, and 9 months, unexpectedly, by 12 months, all groups displayed improved glucose tolerance and insulin sensitivity compared to earlier time points (P < 0.001 and P = 0.02, respectively). Our study provides evidence that dietary fat quality impacts metabolic risk factors in a sex‐specific manner.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.