TY - JOUR

T1 - Diet-Induced Weight Loss Alters Functional Brain Responses during an Episodic Memory Task

AU - Boraxbekk, Carl Johan

AU - Stomby, Andreas

AU - Ryberg, Mats

AU - Lindahl, Bernt

AU - Larsson, Christel

AU - Nyberg, Lars

AU - Olsson, Tommy

N1 - Publisher Copyright: © 2015 S. Karger GmbH, Freiburg.

PY - 2015/9/1

Y1 - 2015/9/1

N2 - Objective: It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. Methods: 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Results: Episodic memory performance improved significantly (p = 0.010) after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA). Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Conclusions: Diet-induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity.

AB - Objective: It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. Methods: 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Results: Episodic memory performance improved significantly (p = 0.010) after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA). Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Conclusions: Diet-induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity.

KW - Diet interventions

KW - Episodic memory

KW - Functional magnetic resonance imaging

KW - Hippocampus

KW - Obesity

UR - http://www.scopus.com/inward/record.url?scp=84936971562&partnerID=8YFLogxK

U2 - 10.1159/000437157

DO - 10.1159/000437157

M3 - Journal article

C2 - 26139105

AN - SCOPUS:84936971562

VL - 8

SP - 261

EP - 272

JO - Obesity Facts

JF - Obesity Facts

SN - 1662-4025

IS - 4

ER -