A high-fat high-sugar diet predicts poorer hippocampal-related memory and a reduced ability to suppress wanting under satiety.

Abstract

A high-fat high-sugar diet predicts poorer hippocampal-related memory and a reduced ability to suppress wanting under satiety Copyright and reuse:Sussex Research Online is a digital repository of the research output of the University.Copyright and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable, the material made available in SRO has been checked for eligibility before being made available.Copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Animal data indicate that greater intake of fats and sugars prevalent in a Western diet impairs hippocampal memory and tests of behavioral inhibition known to be related to hippocampal function (e.g., feature negative discrimination tasks). It has been argued that such high fat high sugar diets (HFS) impair the hippocampus, which then becomes less sensitive to modulation by physiological state. Thus retrieval of motivationally salient memories (e.g., when seeing or smelling food) occurs irrespective of state. Here we examine whether evidence of similar effects can be observed in humans using a correlational design. Healthy human participants (N = 94), who varied in their habitual consumption of a HFS diet, completed the verbal paired associate (VPA) test, a known hippocampal-dependent process, as well as liking and wanting ratings of palatable snack foods, assessed both hungry and sated. Greater intake of a HFS diet was significantly associated with a slower VPA learning rate, as predicted. Importantly, for those who regularly consumed a HFS diet, while reductions in liking and wanting occurred between hungry and sated states, the reduction in wanting was far smaller relative to liking. The latter effect was strongly related to VPA learning rate, suggestive of hippocampal mediation. In agreement with the animal literature, human subjects with a greater intake of a HFS diet show deficits in hippocampal-dependent learning and memory, and their desire to consume palatable food is less affected by physiological state -a process we suggest that is also hippocampal related.

Phenotypic heterogeneity of obesity‐related brain vulnerability: one‐size interventions will not fit all

“…53 Conversely, Western-style diets, made up of high saturated and trans fat content and refined sugars, have been linked to impairment in memory and cognitive flexibility and later cognitive decline. 54,55 Therefore, a key strategy for preserving brain health and preventing cognitive decline may be through modifying intake of dietary fat.…”

Facial EMG Correlates of Subjective Hedonic Responses During Food Consumption

“…We assessed liking and wanting as subjective ratings, which have been used in many studies that tested hedonic responses to food [31] as well as valence and arousal, which have been assessed in many emotional studies [5,6]. Several previous studies found that the liking and wanting ratings generally were positively correlated during visual and oral food processing tasks [32], although some studies found a dissociation between these ratings under certain conditions [33][34][35]. We measured facial EMG from the corrugator supercilii and zygomatic major muscles as the physiological measures of interest.…”

Hippocampal-dependent appetitive control is impaired by experimental exposure to a Western-style diet

“…That a WS-diet affects human hippocampal function in young lean healthy people-paralleling animal studies who typically use young lean healthy rats or mice [14]-is a fairly recent finding. Early studies identified an association between consumption of a WS-diet, assessed by a validated food frequency measure, and performance on neuropsychological tests that are known to be dependent upon hippocampal function [15][16][17]. These studies included tests of verbal paired-associate learning, visual memory and episodic memory-with associations to a WS-diet sustained even after controlling for other likely sources of variability (e.g.…”

“…A recent study attempted to more directly test the role of hippocampal-dependent processes in the control of appetite by interoceptive satiety cues [15]. Using a cross-sectional design, hungry participants who habitually ate either a healthy or a WS-diet, viewed familiar palatable snacks and reported how much they wanted to eat them.…”