umu.sePublikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Diet-Induced Weight Loss alters Functional Brain Responses during an Episodic Memory Task
Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Samhällsvetenskapliga fakulteten, Centrum för befolkningsstudier (CBS).ORCID-id: 0000-0002-4458-6475
Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
Vise andre og tillknytning
2015 (engelsk)Inngår i: Obesity Facts, ISSN 1662-4025, E-ISSN 1662-4033, Vol. 8, s. 261-272Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

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.

sted, utgiver, år, opplag, sider
2015. Vol. 8, s. 261-272
Emneord [en]
Functional magnetic resonance imaging, Episodic memory, Obesity, Diet interventions, Hippocampus
HSV kategori
Identifikatorer
URN: urn:nbn:se:umu:diva-101039DOI: 10.1159/000437157ISI: 000360933400004PubMedID: 26139105OAI: oai:DiVA.org:umu-101039DiVA, id: diva2:796149
Tilgjengelig fra: 2015-03-18 Laget: 2015-03-18 Sist oppdatert: 2018-06-07bibliografisk kontrollert
Inngår i avhandling
1. Brain function and glucocorticoids in obesity and type 2 diabetes including effects of lifestyle interventions
Åpne denne publikasjonen i ny fane eller vindu >>Brain function and glucocorticoids in obesity and type 2 diabetes including effects of lifestyle interventions
2015 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Alternativ tittel[sv]
Effekter av livsstilsförändring på hjärnfunktion och stresshormoner vid fetma och typ 2 diabetes
Abstract [en]

Background Obesity and associated metabolic dysregulation are linked to impaired cognitive function and alterations in brain structure, which increases the risk of age-related dementia. Increased glucocorticoid (GC) exposure may be a potential mediator of these negative effects on the brain.

Methods and results In paper 1, we tested the relationship between cortisol levels, brain morphology and cognitive function in 200 women and men. Salivary cortisol levels were negatively related to cortical surface areas in prefrontal brain regions in both sexes. In participants with type 2 diabetes, high salivary cortisol levels were associated with lower memory performance. In paper 2, we tested in 70 overweight women the effects on tissue-specific GC metabolism of a Paleolithic diet or a diet following the Nordic nutrition recommendations. The 24-month interventions led to decreased expression of the GC-activating enzyme 11βHSD1 in adipose tissue, interpreted as a normalization of an obesity-related disturbance in GC metabolism. Furthermore, GC metabolism by 5α-reductase increased substantially after 2 years, an unexpected and novel result. The outcomes did not differ by diet. In paper 3, 20 women included in paper 2 were examined with functional magnetic resonance imaging (fMRI) while performing a memory task at baseline and after 6 months. Memory performance improved and functional brain responses increased in the hippocampus. Once again, the results were similar in both diet groups. In paper 4, 24 overweight participants with type 2 diabetes were examined with fMRI, using the same memory test as in paper 3, at baseline and after 12 weeks of intervention with a Paleolithic diet with or without exercise training. Functional brain response increased in the hippocampus, but memory was not improved. The addition of physical exercise did not alter the results.

Conclusion Cortisol levels are linked to prefrontal brain structure and, at least in type 2 diabetes, lower memory performance. Furthermore, the dysregulated GC metabolism in obesity can be reversed by long-term diet- induced weight loss. Finally, dietary interventions with associated metabolic improvements alter functional brain responses during memory testing, including increased activation of the hippocampus. Whether these changes are linked to alterations in GC exposure and mediate improved cognition requires further study. 

sted, utgiver, år, opplag, sider
Umeå: Umeå University, 2015. s. 85
Serie
Umeå University medical dissertations, ISSN 0346-6612 ; 1710
Emneord
Obesity, type 2 diabetes, glucocorticoid, cortisol, 11beta hydroxysteroid dehydrogenase type 1, episodic memory, functional magnetic resonance imaging, paleolithic diet, exercise
HSV kategori
Forskningsprogram
invärtesmedicin; medicin
Identifikatorer
urn:nbn:se:umu:diva-102596 (URN)978-91-7601-250-5 (ISBN)
Disputas
2015-05-27, Bergasalen, Norrlands Universitetssjukhus, Umeå, 13:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2015-05-06 Laget: 2015-04-28 Sist oppdatert: 2018-06-07bibliografisk kontrollert

Open Access i DiVA

fulltext(697 kB)217 nedlastinger
Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 697 kBChecksum SHA-512
87dcfc0c4066a9b4ce5ce6065428804ee7d54685225c27d74d89b9e29349d8d0c33c95d1e11d8a02aa15a2d66f2413b45488b0815716f6ccf61456057a8bacb2
Type fulltextMimetype application/pdf

Andre lenker

Forlagets fulltekstPubMed

Personposter BETA

Boraxbekk, Carl-JohanStomby, AndreasRyberg, MatsLindahl, BerntLarsson, ChristelNyberg, LarsOlsson, Tommy

Søk i DiVA

Av forfatter/redaktør
Boraxbekk, Carl-JohanStomby, AndreasRyberg, MatsLindahl, BerntLarsson, ChristelNyberg, LarsOlsson, Tommy
Av organisasjonen
I samme tidsskrift
Obesity Facts

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 217 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

doi
pubmed
urn-nbn

Altmetric

doi
pubmed
urn-nbn
Totalt: 1337 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf