title: Aerobic fitness and the brain: increased N-acetyl-aspartate and choline concentrations in endurance-trained middle-aged adults.
abstract: Engagement in regular aerobic exercise is associated with cognitive benefits, but information on the mechanisms governing these changes in humans is limited. The goal of the current study was to compare neurometabolite concentrations relating to cellular metabolism, structure, and viability in endurance-trained and sedentary middle-aged adults. Twenty-eight endurance-trained and 27 sedentary adults, aged 40-65 years, underwent general health assessment, cardiorespiratory fitness measurement, neuropsychological testing, and proton magnetic resonance spectroscopy ((1)H MRS). (1)H MRS was used to examine N-acetyl-aspartate (NAA), creatine (Cr), myo-inositol (mI), choline (Cho), and glutamate (Glu) concentrations in frontal and occipitoparietal grey matter. Group differences in concentrations of NAA, Cho, mI, and Glu, calculated as ratios over Cr, were explored using ANOVA. There were no significant differences in global cognitive function, memory, and executive function performance between the groups. In comparison to sedentary adults, the endurance-trained group displayed significantly higher NAA/Cr in the frontal grey matter (F(1, 53) = 5.367, p = 0.024) and higher Cho/Cr in the occipitoparietal grey matter (F(1, 53) = 5.138, p = 0.028). Within our middle-aged sample, endurance-trained adults demonstrated higher levels of NAA/Cr in the frontal grey matter and higher Cho/Cr in the occipitoparietal grey matter. Higher levels of NAA may indicate greater neuronal integrity and higher cerebral metabolic efficiency in association with cardiorespiratory fitness, whereas increased Cho may represent increased phospholipid levels secondary to neural plasticity.
authors.affiliation: Department of Psychology, The University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Mitzi M
authors.initials: MM
authors.lastname: Gonzales
authors.forename: Takashi
authors.initials: T
authors.lastname: Tarumi
authors.forename: Sonya
authors.initials: S
authors.lastname: Kaur
authors.forename: Nantinee
authors.initials: N
authors.lastname: Nualnim
authors.forename: Bennett A
authors.initials: BA
authors.lastname: Fallow
authors.forename: Martha
authors.initials: M
authors.lastname: Pyron
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Andreana P
authors.initials: AP
authors.lastname: Haley
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002794:Choline / Q000378:metabolism*; D003071:Cognition / Q000502:physiology; D003401:Creatine / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline