A High-Fat Diet Causes Impairment in Hippocampal Memory and Sex-Dependent Alterations in Peripheral Metabolism

Abstract EN

While high-fat diets are associated with rising incidence of obesity/type-2 diabetes and can induce metabolic and cognitive deficits, sex-dependent comparisons are rarely systematically made.

Effects of exclusive consumption of a high-fat diet (HFD) on systemic metabolism and on behavioral measures of hippocampal-dependent memory were compared in young male and female LE rats.

Littermates were fed from weaning either a HFD or a control diet (CD) for 12 wk prior to testing.

Sex-different effects of the HFD were observed in classic metabolic signs associated with type-2 diabetes.

Males fed the HFD became obese, and had elevated fasted blood glucose levels, elevated corticosterone, and impaired glucose-tolerance, while females on the HFD exhibited only elevated corticosterone.

Regardless of peripheral metabolism alteration, rats of both sexes fed the HFD were equally impaired in a spatial object recognition memory task associated with impaired hippocampal function.

While the metabolic changes reported here have been characterized previously in males, the set of diet-induced effects observed here in females are novel.

Impaired memory can have significant cognitive consequences, over the short-term and over the lifespan.

A significant need exists for comparative research into sex-dependent differences underlying obesity and metabolic syndromes relating systemic, cognitive, and neural plasticity mechanisms.