The Protective Effect of Omega-3 Fatty Acid on Cognitive Function Among Patients With Mild Dementia

Background： Dementia is a progressive, devastating, and fatal neurodegenerative disorder. Alzheimer's disease (AD) is the most common cause of dementia, accounting for more than 50% of patients with dementia. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the major bioactive components of n-3 polyunsaturated fatty acids (n-3 PUFAs) , might connect to the etiology of several neuropsychiatric diseases. To our knowledge, it has never been studied to look at the different effects of DHA, EPA and their combination on associated symptoms of AD. Objectives To examine the effects of DHA, EPA and their combination on associated symptoms of AD, including cognitive function, depressive symptoms, and functional ability. Method This is a randomized, double-blind, placebo-controlled, 24-month follow-up study, enrolling 200-400 patients with mild AD (Mini-Mental Status Examination (MMSE) 19-26 or Clinical Dementia Rating (CDR) 0.5-1). Cognitive ability is assessed by the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and the MMSE. Mood status is assessed by Geriatric Depression Scale (GDS). Functional ability is assessed by the Alzheimer Disease Cooperative Study activities of daily living (ADCS-ADL) and global function by the CDR, quality of life scale (QOL-AD). Brain function is assessed by resting state brain magnetic resonance imaging (MRI).