Does Long-Term High Fat Diet Always Lead to Smaller Hippocampi Volumes, Metabolite Concentrations, and Worse Learning and Memory? A Magnetic Resonance and Behavioral Study in Wistar Rats
PBN-AR
Instytucja
Instytut Medycyny Doświadczalnej i Klinicznej im. Mirosława Mossakowskiego Polskiej Akademii Nauk
Informacje podstawowe
Główny język publikacji
en
Czasopismo
PLoS One
ISSN
1932-6203
EISSN
Wydawca
PUBLIC LIBRARY SCIENCE
DOI
URL
Rok publikacji
2015
Numer zeszytu
10
Strony od-do
0139987-0139987
Numer tomu
10
Identyfikator DOI
Liczba arkuszy
1,02
Słowa kluczowe
en
BODY-MASS INDEX
PROTEIN-INTAKE
KETOGENIC DIET
AGED RATS
BRAIN
OBESITY
COGNITION
SPECTROSCOPY
HEALTHY
GLUCOSE
Open access
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Creative Commons — Uznanie autorstwa-Niekomercyjne-Na tych samych warunkach
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Razem z publikacją
Streszczenia
Język
en
Treść
Background Obesity is a worldwide epidemic with more than 600 million affected individuals. Human studies have demonstrated some alterations in brains of otherwise healthy obese individuals and elevated risk of neurodegenerative disease of old age; these studies have also pointed to slightly diminished memory and executive functions among healthy obese individuals. Similar findings were obtained in animal models of obesity induced by high fat diet. On the other hand, low carbohydrate high fat diets are currently promoted for losing weight (e.g., Atkin's style diets). However, the long-term effects of such diets are not known. Additionally, high fat diets leading to (mild) ketonemia were shown to improve brain function in elderly humans and in some animal models. Aim To evaluate the hypothesis that long-term use of a high fat diet was associated with decreases in spatial memory, smaller hippocampi and hippocampi metabolite concentrations in Wistar rats. Methods Twenty five male Wistar rats were put on high fat diet (HFD; 60\% calories from fat, 30\% from carbohydrates) on their 55th day of life, while 25 control male rats (CONs) remained on chow. Adequate levels of essential nutrients were provided. Both groups underwent memory tests in 8-arm radial maze at 3rd, 6th, 9th, and 12th month. H-1 magnetic resonance spectroscopy was employed to measure concentrations of tNAA (marker of neuronal integrity) at one month and one year, whereas MRI was used to evaluate hippocampal volumes. Results Obese rats (OBRs) consumed similar amount of calories as CONs, but less proteins. However, their protein intake was within recommended amounts. Throughout the experiment OBRs had statistically higher concentrations of blood ketone bodies than CONs, but still within normal values. At post-mortem assessment, OBRs had 38\% larger fat deposits than CONs (p<0.05), as evaluated by volume of epididymis fat, an acknowledged marker of fat deposits in rats. Contrary to our expectations, OBRs had better scores of memory behavioral tasks than CONs throughout the experiment. At one year, their hippocampi were by 2.6\% larger than in CONs (p = 0.05), whereas concentration of tNAA was 9.8\% higher (p = 0.014). Conclusion Long-term HFD in our study resulted in better memory, larger hippocampal volumes, as well as higher hippocampal metabolite concentrations, possibly due to increased levels of blood ketone bodies. The results should be interpreted with caution, as results from animal models do not necessarily directly translate in human condition.
Cechy publikacji
ORIGINAL_ARTICLE
Inne
System-identifier
680275
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