title: Effects of DHA Supplementation on Hippocampal Volume and Cognitive Function in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized, Double-Blind, Placebo-Controlled Trial.
abstract: Docosahexaenoic acid (DHA) is important for brain function, and higher DHA intake is inversely correlated with relative risk of Alzheimer's disease. The potential benefits of DHA supplementation in people with mild cognitive impairment (MCI) have not been fully examined. Our study aimed to determine the effect of DHA supplementation on cognitive function and hippocampal atrophy in elderly subjects with MCI. This was a randomized, double-blind, placebo-controlled trial in Tianjin, China. 240 individuals with MCI aged 65 years and over were recruited and equalized randomly allocated to the DHA or the placebo group. Participants received 12-month DHA supplementation (2 g/day) or corn oil as placebo. Both global and specific subdomains of cognitive function and hippocampal volume were measured at baseline, 6 months, and 12 months. Both changes were analyzed by repeated-measure analysis of variance (ANOVA). This trial has been registered: ChiCTR-IOR-15006058. A total of 219 participants (DHA: 110, Placebo: 109) completed the trial. The change in mean serum DHA levels was greater in the intervention group (+3.85%) compared to the control group (+1.06%). Repeated-measures analyses of covariance showed that, over 12 months, there was a significant difference in the Full-Scale Intelligence Quotient (ηp2 = 0.084; p = 0.039), Information (ηp2 = 0.439; p = 0.000), and Digit Span (ηp2 = 0.375; p = 0.000) between DHA-treated versus the placebo group. In addition, there were significant differences in volumes of left hippocampus (ηp2 = 0.121, p = 0.016), right hippocampus (ηp2 = 0.757, p = 0.008), total hippocampus (ηp2 = 0.124, p = 0.023), and global cerebrum (ηp2 = 0.145, p = 0.032) between the two groups. These findings suggest that DHA supplementation (2 g/day) for 12 months in MCI subjects can significantly improve cognitive function and slow the progression of hippocampal atrophy. Larger, longer-term confirmatory studies are warranted.
authors.affiliation: Department of Infectious Disease, General Hospital, Tianjin Medical University, Tianjin, China.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Rujuan
authors.initials: R
authors.lastname: Miao
authors.affiliation: Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Nutrition and Food Science, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Tianfeng
authors.initials: T
authors.lastname: Wu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Ma
mesh_terms: D000704:Analysis of Variance; D002849:Chromatography, Gas; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000178:diet therapy* / Q000473:pathology*; D004035:Diet Therapy / Q000379:methods; D004281:Docosahexaenoic Acids / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000187:drug effects*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests
chemical_list: D004281:Docosahexaenoic Acids
keywords: Alzheimer’s disease; cognitive function; docosahexaenoic acid; hippocampal volume; randomized controlled trial