title: High-intensity physical activity modulates diet effects on cerebrospinal amyloid-β levels in normal aging and mild cognitive impairment.
abstract: We previously showed that amyloid-β 1-42 (Aβ(42)) levels in cerebrospinal fluid (CSF) were markedly altered in response to a 4-week dietary intervention in normal aging and mild cognitive impairment (MCI). Here, we re-examined the data to assess whether diet-induced effects on CSF Aβ(42) were modulated by high intensity physical activity (hi-PA). Normal older adults (n = 18, mean age = 68.6 ± 7.4 y) and adults with amnestic MCI (n = 23, mean age = 68.0 ± 6.5 y) received a low saturated fat/low glycemic index (LOW) diet or a high saturated fat/high glycemic index (HIGH) diet, and CSF levels of Aβ(42), tau, and IL-8 were measured at baseline and week 4. Pre-study activity levels were assessed using a 7-d questionnaire, and weekly duration of hi-PA was quantified. At baseline, increased hi-PA in normals predicted lower CSF levels of tau (r = -0.54, p = 0.020) and IL-8 (r = -0.70, p = 0.025). Diet-induced effects on CSF Aβ(42) during the intervention study were modulated by hi-PA, and the nature of this effect differed for normals and MCI (ANOVA, p = 0.039). That is, for normal adults, increased hi-PA attenuated the effects of the HIGH diet on CSF Aβ(42) whereas in MCI, increased hi-PA potentiated the effects of the LOW diet. Our results suggest that normal adults who engage in hi-PA are less vulnerable to the pathological effects of an unhealthy diet, while in MCI, the benefit of a healthy diet on Aβ modulation is greatest when paired with hi-PA. Exercise may thus interact with diet to alter pathological processes that ultimately modify risk of Alzheimer's disease.
authors.affiliation: Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA. ldbaker@uw.edu
authors.forename: Laura D
authors.initials: LD
authors.lastname: Baker
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Bayer-Carter
authors.forename: Jeannine
authors.initials: J
authors.lastname: Skinner
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Montine
authors.forename: Brenna A
authors.initials: BA
authors.lastname: Cholerton
authors.forename: Maureen
authors.initials: M
authors.lastname: Callaghan
authors.forename: James B
authors.initials: JB
authors.lastname: Leverenz
authors.forename: Brooke K
authors.initials: BK
authors.lastname: Walter
authors.forename: Elaine
authors.initials: E
authors.lastname: Tsai
authors.forename: Nadia
authors.initials: N
authors.lastname: Postupna
authors.forename: Johanna
authors.initials: J
authors.lastname: Lampe
authors.forename: Suzanne
authors.initials: S
authors.lastname: Craft
mesh_terms: D000368:Aged; D000375:Aging / Q000134:cerebrospinal fluid* / Q000523:psychology; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid* / Q000178:diet therapy / Q000523:psychology; D004032:Diet / Q000009:adverse effects / Q000379:methods; D018752:Diet, Fat-Restricted / Q000379:methods; D059305:Diet, High-Fat / Q000009:adverse effects / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D040242:Risk Reduction Behavior; D011795:Surveys and Questionnaires
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)