title: Reduced nucleus accumbens and caudate nucleus activation to a pleasant taste is associated with obesity in older adults.
abstract: Although obesity is recognized as a global health epidemic, insufficient research has been directed to understanding the rising prevalence of obesity in the fastest growing segment of the population, older adults. Late-life obesity has been linked to declines in physical health and cognitive function, with implications not only for the individual, but also for society. We investigated the hypothesis that altered brain responses to food reward is associated with obesity, using fMRI of response to pleasant and aversive taste stimuli in young and older adults performing a hedonic evaluation task. Correlations between higher levels of abdominal fat/body mass index and reduced fMRI activation to sucrose in dopamine-related brain regions (caudate, nucleus accumbens) were large in older adults. Significant associations between a hypofunctioning reward response and obesity suggest the hypothesis that decreased dopamine functioning may be a plausible mechanism for weight gain in older adults.
authors.affiliation: San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA 92120–4913, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Green
authors.forename: Aaron
authors.initials: A
authors.lastname: Jacobson
authors.forename: Lori
authors.initials: L
authors.lastname: Haase
authors.forename: Claire
authors.initials: C
authors.lastname: Murphy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology; D002421:Caudate Nucleus / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009714:Nucleus Accumbens / Q000503:physiopathology*; D009765:Obesity / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D012201:Reward; D013649:Taste / Q000502:physiology*; D013651:Taste Disorders / Q000209:etiology / Q000503:physiopathology*; D055815:Young Adult