Chronic consumption of a high-fat diet: investigation of negative consequences

Abstract

Chronic consumption of a high-fat diet is a lifestyle factor that increases the risk for cognitive impairment (Granholm et al., 2008; Greenwood & Winocur, 2005; Mattson, 2004; Winocur & Greenwood, 2005). A high-fat diet appears to facilitate cognitive impairment through the promotion of insulin resistance (Greenwood & Winocur, 2005; Stranahan et al., 2008; Winocur & Greenwood, 2005). A gap in the literature is an established timeframe of the progression and underlying mechanism, which study in animals would better afford. Furthermore, A limited number of studies have investigated the relationship between a high-fat diet and behavioral dysregulation such as anxiety and depression. The 1st aim of the study was to determine if consumption of a high-fat diet leads to cognitive impairment and behavioral dysfunction at 3, 8, or 13 weeks of consumption. The 2nd aim was to determine if cholesterol levels and HBP activity are aberrantly increased in specific regions in mice that display feeding induced cognitive/behavioral dysfunction. Consumption of the experimental specialty diets produced a number of significant behavioral effects. These significant effects began to emerge after only 3 weeks of low-and high-fat feeding with increased anxiety-like behavior displayed higher in the high-fat diet group for the Elevated Plus Maze and Open Field Test. There was increased thigmotactic behavior and floating in the low-fat diet group in the Morris Water Maze (MWM) task, therefore making cognitive assessment uninterpretable. This pattern in the behavioral tasks were more robust in the 8 week group and alleviated in the 13 week group. There was only a significant difference in depression-like symptoms in the Forced Swim (FS) Task in the 3 week group. Cholesterol analysis is still under review in Dr. Elmendorf’s lab to correlate cholesterol levels and cognitive/behavioral impairment.