title: Linoleic acid causes greater weight gain than saturated fat without hypothalamic inflammation in the male mouse.
abstract: A significant change in the Western diet, concurrent with the obesity epidemic, was a substitution of saturated fatty acids with polyunsaturated, specifically linoleic acid (LA). Despite increasing investigation on type as well as amount of fat, it is unclear which fatty acids are most obesogenic. The objective of this study was to determine the obesogenic potency of LA vs. saturated fatty acids and the involvement of hypothalamic inflammation. Forty-eight mice were divided into four groups: low-fat or three high-fat diets (HFDs, 45% kcals from fat) with LA comprising 1%, 15% and 22.5% of kilocalories, the balance being saturated fatty acids. Over 12 weeks, bodyweight, body composition, food intake, calorimetry, and glycemia assays were performed. Arcuate nucleus and blood were collected for mRNA and protein analysis. All HFD-fed mice were heavier and less glucose tolerant than control. The diet with 22.5% LA caused greater bodyweight gain, decreased activity, and insulin resistance compared to control and 1% LA. All HFDs elevated leptin and decreased ghrelin in plasma. Neuropeptides gene expression was higher in 22.5% HFD. The inflammatory gene Ikk was suppressed in 1% and 22.5% LA. No consistent pattern of inflammatory gene expression was observed, with suppression and augmentation of genes by one or all of the HFDs relative to control. These data indicate that, in male mice, LA induces obesity and insulin resistance and reduces activity more than saturated fat, supporting the hypothesis that increased LA intake may be a contributor to the obesity epidemic.
authors.affiliation: Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Nutritional Sciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Kyle J
authors.initials: KJ
authors.lastname: Mamounis
authors.affiliation: Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Yasrebi
authors.affiliation: Department of Animal Sciences, School of Environmental & Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Nutritional Sciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; New Jersey Institute for Food, Nutrition, and Health, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA. Electronic address: ta.roepke@rutgers.edu.
authors.forename: Troy A
authors.initials: TA
authors.lastname: Roepke
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D054428:Chemokine CX3CL1 / Q000378:metabolism; D018752:Diet, Fat-Restricted; D004660:Encephalitis / Q000139:chemically induced / Q000209:etiology* / Q000473:pathology; D005227:Fatty Acids / Q000009:adverse effects*; D054439:Ghrelin / Q000097:blood; D005947:Glucose / Q000378:metabolism; D007031:Hypothalamus / Q000473:pathology; D020738:Leptin / Q000097:blood; D019787:Linoleic Acid / Q000009:adverse effects*; D008297:Male; D008810:Mice, Inbred C57BL; D015430:Weight Gain / Q000187:drug effects
chemical_list: D054428:Chemokine CX3CL1; C515539:Cx3cl1 protein, mouse; D005227:Fatty Acids; D054439:Ghrelin; D020738:Leptin; D002245:Carbon Dioxide; D019787:Linoleic Acid; D005947:Glucose
keywords: HFD; Hypothalamic inflammation; Linoleic acid; Obesity; PUFA; Saturated fat