A meal enriched in saturated fat acutely impairs cognitive performance in obese men

• Published in: Physiology & behavior Vol. 244; p. 113664
• Main Authors: Ruegsegger, Gregory N., Rappaport, Chapin I., Hill, Justin J., Jochum, Kelly A., Challeen, Erik S., Roth, Michael C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2022
• Subjects: Blood Glucose; body composition; Cognition; cognitive disorders; Cross-Over Studies; dementia; Dietary fat; Dietary Fats - pharmacology; Executive function; Fatty Acids; glucose; glucose tolerance; Humans; Insulin; Insulin resistance; interleukin-6; Male; Meals; Memory; Nutrition; Obesity; Postprandial Period; saturated fats; Single-Blind Method; triacylglycerols; Dietary fat; Insulin resistance; Executive function; Nutrition; Memory
• ISSN: 0031-9384; 1873-507X; 1873-507X
• DOI: 10.1016/j.physbeh.2021.113664

•Obesity and insulin resistance are primary risk factors for dementia development.•We investigated how meals with different types of dietary fat influence cognition.•Saturated fat acutely impairs cognitive function in obese, but not lean, men.•Impairments in cognition in obese men associate with diet-induced insulin resistance. Diets chronically high in saturated fat (SFA) associate with obesity and insulin resistance (IR), which in turn associate with cognitive decline and dementia. However, understanding how acute SFA consumption influences cognition is less clear despite short-term SFA-enriched diets inducing whole-body IR. We examined how consuming meals enriched with SFA or monounsaturated fat (MUFA) acutely influence cognitive function in lean and obese men. We hypothesized that greater diet-induced IR following a SFA-enriched meal would associate with decreased cognitive performance. Twelve lean and 12 obese males ingested meals containing no fat (CTL), enriched with SFA, or enriched with MUFA in a single-blind, randomized fashion. Cognitive testing and blood sampling were performed pre- and 2 h post-meal. Oral glucose tolerance (OGTT) and body composition were also assessed. At baseline, fasting glucose, insulin, HOMA-IR, triglyceride, IL-6, and 2-hr glucose during an OGTT were higher in obese men (p < 0.001), while executive function (Stroop Test and Trail Making Test B-A) and working memory (Digit Span Test) were lower in obese men (p < 0.05). In response to the CTL and MUFA-enriched, no differences in cognitive measures were observed in lean or obese subjects. Following a SFA-enriched meal, obese subjects scored worse during cognitive testing (Stroop Test, Trail Making Test B-A, and Digit Span Test) compared to pre-meal scores (p < 0.05). These impairments in cognitive testing scores following the SFA-enriched meal associated with increased HOMA-IR (p < 0.01) and decreased plasma IL-6 (p < 0.05). No changes in cognitive function were observed in lean subjects following a SFA-enriched meal. These data demonstrate that cognitive performance of obese men acutely worsens following a high-SFA meal. Reductions in cognitive performance associated with increased IR, suggesting that diet-induced IR may acutely decrease cognitive function.