***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Dietary intake of fish and the omega-3 fatty acids have been associated with lower risk of Alzheimer disease and stroke . OBJECTIVE To examine whether intakes of fish and the omega-3 fatty acids protect against  age-related cognitive decline .  DESIGN Prospect i ve cohort study . SETTING Geographically defined Chicago , Ill , community . PARTICIPANTS Residents , 65 years and older , who participated in the Chicago Health and Aging Project . MAIN OUTCOME MEASURE Change in a global cognitive score estimated from mixed models . The global score was computed by summing scores of 4 st and ardized tests . In-home cognitive assessment  s were performed 3 times over 6 years of follow-up . RESULTS Cognitive scores declined on average at a rate of 0.04 st and ardized units per year ( SU/y ) . Fish intake was associated with a slower rate of cognitive decline in mixed models adjusted for age , sex , race , education , cognitive activity , physical activity , alcohol consumption , and total energy intake . Compared with a decline rate in score of -0.100 SU/y among persons who consumed fish less than weekly , the rate was 10 % slower ( -0.090 SU/y ) among persons who consumed 1 fish meal per week and 13 % slower ( -0.088 SU/y ) among persons who consumed 2 or more fish meals per week . The fish association was not accounted for by cardiovascular-related conditions or fruit and vegetable consumption but was modified after adjustment for intakes of saturated , polyunsaturated , and trans fats . There was little evidence that the omega-3 polyunsaturated fatty acids were associated with cognitive change . CONCLUSIONS Fish consumption may be associated with slower cognitive decline with age . Further study is needed to determine whether fat composition is the relevant dietary constituent Background Some studies have suggested an association between omega-3 long-chain polyunsaturated fatty acids ( n-3 LC PUFAs ) and better cognitive outcomes in older adults . To date , only two r and omised , controlled trials have assessed the effect of n-3 LC PUFA supplementation on cognitive function in older cognitively healthy population s. Of these trials only one found a benefit , in the subgroup carrying the ApoE-ε4 allele . The benefits of n-3 LC PUFA supplementation on cognitive function in older normal population s thus still remain unclear . The main objective of the current study was to provide a comprehensive assessment of the potential of n-3 LC PUFAs to slow cognitive decline in normal elderly people , and included ApoE-ε4 allele carriage as a potential moderating factor . The detailed methodology of the trial is reported herein . Methods The study was a parallel , 18-month , r and omised , double-blind , placebo-controlled intervention with assessment at baseline and repeated 6-monthly . Participants ( N = 391 , 53.7 % female ) aged 65 - 90 years , English-speaking and with normal cognitive function , were recruited from metropolitan Adelaide , South Australia . Participants in the intervention arm received capsules containing fish-oil at a daily dosage of 1720 mg of docosahexaenoic acid and 600 mg of eicosapentaenoic acid while the placebo arm received the equivalent amount of olive oil in their capsules . The primary outcome is rate of change in cognitive performance , as measured by latent variables for the cognitive constructs ( encompassing Reasoning , Working Memory , Short-term Memory , Retrieval Fluency , Inhibition , Simple and Choice-Reaction Time , Perceptual Speed , Odd-man-out Reaction Time , Speed of Memory Scanning , and Psychomotor Speed ) and assessed by latent growth curve modeling . Secondary outcomes are change in the Mini-mental State Examination , functional capacity and well-being ( including health status , depression , mood , and self-report cognitive functioning ) , blood pressure , and biomarkers of n-3 LC PUFA status , glucose , lipid metabolism , inflammation , oxidative stress , and DNA damage . Trial registration Australia and New Zeal and Clinical Trials Register ( ANZCTR ) : Given evidence that eicosapentaenoic acid ( EPA ) , docosahexaenoic acid ( DHA ) , and anthocyanin-rich blueberries provide neurocognitive benefit , we investigated long-term supplementation in older adults with cognitive complaints .  In a 24-week r and omized , double-blind , placebo-controlled trial , elderly men and women received daily fish oil ( FO ) or blueberry ( BB ) or both . Diet records confirmed that participants reduced background consumption of EPA , DHA , and anthocyanins as prescribed . Erythrocyte EPA + DHA composition increased in the FO groups ( p = 0.0001 ) . Total urinary anthocyanins did not differ between the groups after supplementation but glycoside and native ( food ) forms increased only in the BB-supplemented groups . The FO ( p = 0.03 ) and BB ( p = 0.05 ) groups reported fewer cognitive symptoms , and the BB group showed improved memory discrimination ( p = 0.04 ) , indicating that supplementation improved cognition . Cognitive benefit in the BB group was associated with the presence of urinary anthocyanins reflecting recent BB intake but not with anthocyanin metabolites . However , combined FO + BB treatment was not associated with cognitive enhancement as expected 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 aim ed to determine the effect of DHA supplementation on cognitive function and hippocampal atrophy in elderly subjects with MCI . This was a r and omized , double-blind , placebo-controlled trial in Tianjin , China . 240 individuals with MCI aged 65 years and over were recruited and equalized r and omly 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 BACKGROUND Plasma fatty acids may affect the risk of  cognitive decline in older adults . OBJECTIVES We prospect ively studied the association between plasma fatty acids and  cognitive decline in adults aged 50 - 65 y at baseline and conducted a subgroup analysis . DESIGN From 1987 through 1989 , the Atherosclerosis Risk in Communities ( ARIC ) Study analyzed plasma fatty acids in cholesteryl esters and phospholipids in whites residing in Minneapolis , MN . From 1990 through 1992 and from 1996 through 1998 , 3 neuropsychological tests in the domains of delayed word recall , psychomotor speed , and verbal fluency were administered . We selected cutoffs for statistically reliable cognitive decline in each of these domains and a measure of global cognitive change computed by principal-components analysis . Multivariate logistic regression was conducted . Focusing on n-3 highly unsaturated fatty acids ( HUFAs ) , a subgroup analysis assessed differential association across potential effect modifiers implicated in oxidative stress and increased risk of neurodegenerative disease . RESULTS In the 2251 study subjects , the risk of global cognitive decline increased with elevated palmitic acid in both fractions and with high arachidonic acid and low linoleic acid in cholesteryl esters . Higher n-3 HUFAs reduced the risk of decline in verbal fluency , particularly in hypertensive and dyslipidemic subjects . No significant findings were shown for psychomotor speed or delayed word recall . CONCLUSIONS Promoting higher intakes of n-3 HUFAs in the diet of hypertensive and dyslipidemic persons may have substantial benefits in reducing their risk of cognitive decline in the area of verbal fluency . However , clinical trials are needed to confirm this finding BACKGROUND Very-long-chain n-3 polyunsaturated fatty acids ( n-3 PUFAs ) are suggested to be related to cognitive performance in older adults . However , limited data exist on the association between n-3 PUFAs and performance in specific cognitive domains . OBJECTIVE We evaluated the association between plasma n-3 PUFA proportions and cognitive performance in 5 cognitive domains and determined whether plasma n-3 PUFA proportions predict cognitive change over 3 y. DESIGN We used data from the FACIT trial , in which participants received folic acid or placebo capsules for 3 y. Fatty acid proportions in plasma cholesteryl esters at baseline were measured in 807 men and women aged 50 - 70 y.  Cognitive performance for memory , sensorimotor speed , complex speed , information-processing speed , and word fluency was assessed at baseline and after 3 y. The cross-sectional analyses were based on all 807 participants ; the longitudinal analyses were based only on 404 participants in the placebo group . RESULTS Higher plasma n-3 PUFA proportions predicted less decline in sensorimotor speed ( multiple linear regression coefficient , z score = 0.31 ; 95 % CI : 0.06 , 0.57 ) and complex speed ( 0.40 ; 95 % CI : 0.10 , 0.70 ) over 3 y. Plasma n-3 PUFA proportions did not predict 3-y changes in memory , information-processing speed , or word fluency . The cross-sectional analyses showed no association between plasma n-3 PUFA proportions and performance in any of the 5 cognitive domains . CONCLUSIONS In this population , plasma n-3 PUFA proportions were associated with less decline in the speed-related cognitive domains over 3 y. These results need to be confirmed in r and omized controlled trials Depressive symptoms may increase the risk of progressing from mild cognitive impairment ( MCI ) to dementia . Consumption of n-3 PUFA may alleviate both cognitive decline and depression . The aim of the present study was to investigate the benefits of supplementing a diet with n-3 PUFA , DHA and EPA , for depressive symptoms , quality of life ( QOL ) and cognition in elderly people with MCI . We conducted a 6-month double-blind , r and omised controlled trial . A total of fifty people aged > 65 years with MCI were allocated to receive a supplement rich in EPA ( 1·67 g EPA + 0·16 g DHA/d ; n 17 ) , DHA ( 1·55 g DHA + 0·40 g EPA/d ; n 18 ) or the n-6 PUFA linoleic acid ( LA ; 2·2 g/d ; n 15 ) . Treatment allocation was by minimisation based on age , sex and depressive symptoms ( Geriatric Depression Scale , GDS ) . Physiological and cognitive assessment s , question naires and fatty acid composition of erythrocytes were obtained at baseline and 6 months ( completers : n 40 ; EPA n 13 , DHA n 16 , LA n 11 ) . Compared with the LA group , GDS scores improved in the EPA ( P=0·04 ) and DHA ( P=0·01 ) groups and verbal fluency ( Initial Letter Fluency ) in the DHA group ( P=0·04 ) . Improved GDS scores were correlated with increased DHA plus EPA ( r 0·39 , P=0·02 ) . Improved self-reported physical health was associated with increased DHA . There were no treatment effects on other cognitive or QOL parameters . Increased intakes of DHA and EPA benefited mental health in older people with MCI . Increasing n-3 PUFA intakes may reduce depressive symptoms and the risk of progressing to dementia . This needs to be investigated in larger , depressed sample s with MCI BACKGROUND Epidemiologic and animal studies have suggested that dietary fish or fish oil rich in omega 
    Output:
    
This Systematic Review concludes that omega-3 supplementation might have a positive effect on cognitive function .
Thus , n-3 LCPUFAs could be used as a preventive or therapeutic tool for cognitive decline in aged or elder adults