***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 n-3 polyunsaturated fatty acids improve brain functioning in animal studies , but there is limited study of whether this type of fat protects against Alzheimer disease . OBJECTIVE To examine whether fish consumption and intake of different types of n-3 fatty acids protect against Alzheimer disease . DESIGN Prospect i ve study conducted from 1993 through 2000 , of a stratified r and om sample from a geographically defined community . Participants were followed up for an average of 3.9 years for the development of Alzheimer disease . PATIENTS A total of 815 residents , aged 65 to 94 years , who were initially unaffected by Alzheimer disease and completed a dietary question naire on average 2.3 years before clinical evaluation of incident disease . MAIN OUTCOME MEASURES Incident Alzheimer disease diagnosed in a structured neurologic examination by means of st and ardized criteria . RESULTS A total of 131 sample participants developed Alzheimer disease . Participants who consumed fish once per week or more had 60 % less risk of Alzheimer disease compared with those who rarely or never ate fish ( relative risk , 0.4 ; 95 % confidence interval , 0.2 - 0.9 ) in a model adjusted for age and other risk factors . Total intake of n-3 polyunsaturated fatty acids was associated with reduced risk of Alzheimer disease , as was intake of docosahexaenoic acid ( 22:6n-3 ) . Eicosapentaenoic acid ( 20:5n-3 ) was not associated with Alzheimer disease . The associations remained unchanged with additional adjustment for intakes of other dietary fats and of vitamin E and for cardiovascular conditions . CONCLUSION Dietary intake of n-3 fatty acids and weekly consumption of fish may reduce the risk of incident Alzheimer disease BACKGROUND Few studies have investigated the effects of dietary fats on the development of Alzheimer disease . We examined the associations between intake of specific types of fat and incident Alzheimer disease in a biracial community study . METHODS We performed clinical evaluations on a stratified r and om sample of 815 community residents aged 65 years and older who were unaffected by Alzheimer disease at baseline and who completed a food-frequency question naire a mean of 2.3 years before clinical evaluation . RESULTS After a mean follow-up of 3.9 years , 131 persons developed Alzheimer disease . Intakes of saturated fat and trans-unsaturated fat were positively associated with risk of Alzheimer disease , whereas intakes of omega-6 polyunsaturated fat and monounsaturated fat were inversely associated . Persons in the upper fifth of saturated-fat intake had 2.2 times the risk of incident Alzheimer disease compared with persons in the lowest fifth in a multivariable model adjusted for age , sex , race , education , and apolipoprotein E epsilon4 allele status ( 95 % confidence interval , 1.1 - 4.7 ) . Risk also increased with consumption of trans-unsaturated fats , beginning with the second fifth of intake ( relative risk , 2.4 compared with the lowest fifth ; 95 % confidence interval , 1.1 - 5.3 ) . We observed linear inverse associations between Alzheimer disease and vegetable fat ( P = .002 ) , and , after further adjustment for other types of fat , marginally significant associations with intake of omega-6 polyunsaturated fat ( P = .10 for trend ) and monounsaturated fat ( P = .10 for trend ) . Intakes of total fat , animal fat , and dietary cholesterol were not associated with Alzheimer disease . CONCLUSION High intake of unsaturated , unhydrogenated fats may be protective against Alzheimer disease , whereas intake of saturated or trans-unsaturated ( hydrogenated ) fats may increase risk Aim : To study long-term effects of dietary patterns on dementia and Alzheimer ’s disease ( AD ) . Methods : Of 525 subjects r and omly selected from population -based cohorts surveyed at midlife , a total of 385 ( 73 % ) subjects were re-examined 14 years later in the CAIDE study . A healthy-diet index ( range 0–17 ) was constructed including both healthy and unhealthy dietary components . Results : Persons with a healthy diet ( healthy-diet index > 8 points ) had a decreased risk of dementia ( OR 0.12 , 95 % CI 0.02–0.85 ) and AD ( OR 0.08 , 95 % CI 0.01–0.89 ) compared with persons with an unhealthy diet ( 0–8 points ) , adjusting for several possible confounders . Conclusions : Healthy diet at midlife is associated with a decreased risk of dementia/AD in late life . These findings highlight the importance of dietary patterns and may make more effective measures for dementia/AD prevention or postponement possible Objective To prospect ively examine the relation between the Dietary Approaches to Stop Hypertension ( DASH ) and Western diets and risk of gout ( ie , the clinical endpoint of hyperuricemia ) in men . Design Prospect i ve cohort study . Setting The Health Professionals Follow-up Study . Participants 44 444 men with no history of gout at baseline . Using vali date d food frequency question naires , each participant was assigned a DASH dietary pattern score ( based on high intake of fruits , vegetables , nuts and legumes , low fat dairy products , and whole grains , and low intake of sodium , sweetened beverages , and red and processed meats ) and a Western dietary pattern score ( based on high intake of red and processed meats , French fries , refined grains , sweets , and desserts ) . Main outcome measure Risk of incident gout meeting the preliminary American College of Rheumatology survey criteria for gout , adjusting for potential confounders , including age , body mass index , hypertension , diuretic use , and alcohol intake . Results During 26 years of follow-up , 1731 confirmed cases of incident gout were documented . A higher DASH dietary pattern score was associated with a lower risk for gout ( adjusted relative risk for extreme fifths 0.68 , 95 % confidence interval 0.57 to 0.80 , P value for trend < 0.001 ) . In contrast , a higher Western dietary pattern score was associated with an increased risk for gout ( 1.42 , 1.16 to 1.74 , P=0.005 ) . Conclusion The DASH diet is associated with a lower risk of gout , suggesting that its effect of lowering uric acid levels in individuals with hyperuricemia translates to a lower risk of gout . Conversely , the Western diet is associated with a higher risk of gout . The DASH diet may provide an attractive preventive dietary approach for men at risk of gout CONTEXT Both higher adherence to a Mediterranean-type diet and more physical activity have been independently associated with lower Alzheimer disease ( AD ) risk but their combined association has not been investigated . OBJECTIVE To investigate the combined association of diet and physical activity with AD risk . DESIGN , SETTING , AND PATIENTS Prospect i ve cohort study of 2 cohorts comprising 1880 community-dwelling elders without dementia living in New York , New York , with both diet and physical activity information available . St and ardized neurological and neuropsychological measures were administered approximately every 1.5 years from 1992 through 2006 . Adherence to a Mediterranean-type diet ( scale of 0 - 9 ; trichotomized into low , middle , or high ; and dichotomized into low or high ) and physical activity ( sum of weekly participation in various physical activities , weighted by the type of physical activity [ light , moderate , vigorous ] ; trichotomized into no physical activity , some , or much ; and dichotomized into low or high ) , separately and combined , were the main predictors in Cox models . Models were adjusted for cohort , age , sex , ethnicity , education , apolipoprotein E genotype , caloric intake , body mass index , smoking status , depression , leisure activities , a comorbidity index , and baseline Clinical Dementia Rating score . MAIN OUTCOME MEASURE Time to incident AD . RESULTS A total of 282 incident AD cases occurred during a mean ( SD ) of 5.4 ( 3.3 ) years of follow-up . When considered simultaneously , both  Mediterranean-type diet adherence  ( compared with low diet score , hazard ratio [ HR ] for middle diet score was 0.98 [ 95 % confidence interval { CI } , 0.72 - 1.33 ] ; the HR for high diet score was 0.60 [ 95 % CI , 0.42 - 0.87 ] ; P = .008 for trend ) and physical activity ( compared with no physical activity , the HR for some physical activity was 0.75 [ 95 % CI , 0.54 - 1.04 ] ; the HR for much physical activity was 0.67 [ 95 % CI , 0.47 - 0.95 ] ; P = .03 for trend ) were associated with lower AD risk . Compared with individuals neither adhering to the diet nor participating in physical activity ( low diet score and no physical activity ; absolute AD risk of 19 % ) , those both adhering to the diet and participating in physical activity ( high diet score and high physical activity ) had a lower risk of AD ( absolute risk , 12 % ; HR , 0.65 [ 95 % CI , 0.44 - 0.96 ] ; P = .03 for trend ) . CONCLUSION In this study , both higher Mediterranean-type diet adherence and higher physical activity were independently associated with reduced risk for AD It has been suggested that inflammation is involved in Alzheimer disease ( AD ) pathogenesis . The aim of this study is to evaluate the association between inflammatory aspects of diet and incident AD risk . About 2258 nondemented elderly ( age ≥65 ) in New York who provided dietary information at baseline were followed-up prospect ively for AD development . We examined the composite total Inflammation Factor Rating ( tIFR ) , as a measure of inflammatory impact of foods , in relation with ( i ) serum level of high-sensitivity C-reactive protein ( hsCRP ) and ( ii ) risk of incident AD using Cox proportional hazard model . The tIFR was not associated with serum hsCRP level . After an average of 4.0 years of follow-up , 262 paticipants developed incident AD . The tIFR was not associated with AD risk : compared with the lowest tertile of tIFR ( most proinflammatory ) , hazard ratios ( 95 % confidence interval ) for the highest tertile ( most anti-inflammatory ) was 0.97 ( 0.69 - 1.35 ) ( P-for-trend=0.71 ) , in the adjusted model . We conclude that tIFR might not be a biologically relevant measure of the inflammatory impact of the diet . In addition , although it remains possible that tIFR might be related with some other aspects of inflammation not captured by hsCRP , lack of association with AD risk suggests its limited clinical utility Recently dietary pattern analysis has emerged as a way for examining diet-disease relations in Alzheimer ’s disease . In contrast with the conventional approach , which focuses on a single nutrient or a few nutrients or foods , this method considers overall eating patterns . We examined the dietary patterns defined by factor analysis using data collected with a food-frequency question naire in people with Alzheimer ’s disease ( AD ) as compared to healthy controls . The diet data were obtained during population based study of the prevalence of Alzheimer ’s disease in a population in Pol and . Stratified sampling and r and om selection strategies were combined to obtain a representative population for screening ( age group > 55 ) . From the population screened three times , 71 people were diagnosed with Alzheimer ’s according to DSM-IV , and were recruited for further diet risk factors assessment . A group of people with Alzheimer disease ( n = 71 ; F/M 42/29 ) and the same number of healthy , age and gender matched control were recruited for the study . Patients and their caregivers as well as controls were presented with a food frequency question naire based on the 12 food groups . Factor analysis ( principal component ) was used to derive food patterns . The analysis was conducted using the factor procedure . The factors were rotated by an orthogonal transformation ( Varimax rotation ) to achieve simpler structure with greater interpretability . Using factor analysis , we identified major eating patterns , one for Alzheimer ’s patients and a different one for control group . The AD dietary pattern , FACTOR AD was characterized by a high intake of meat , butter , high-fat dairy products , eggs , and refined sugar , whereas the other pattern , ( FACTOR C ) was characterized by a high intake of grains and vegetables . These data indicate the existence of dietary patterns defined by factor analysis with data from a food frequency question naire , characteristic for Alzheimer ’s disease in a Polish population Objectives : To provide up date d estimates of Alzheimer disease ( AD ) dementia prevalence in the United States from 2010 through 2050 . Methods : Probabilities of AD dementia incidence were calculated from a longitudinal , population -based study including substantial numbers of both black and white participants . Incidence probabilities for single year of age , race , and level of education were calculated using weighted logistic regression and AD dementia diagnosis from 2,577 detailed clinical evaluations of 1,913 people obtained from stratified r and om sample s of previously disease-free individuals in a population of 10,800 . These were combined with US mortality , education , and new US Census Bureau estimates of current and future 
    Output:
    
This literature review indicated that adherence to a healthy dietary pattern  has neuroprotective effects on AD prevention , while unhealthy diet can cause neurodegenerative effects in AD etiology .
In conclusion , our findings showed that adherence to healthy diet can decrease oxidative stress and inflammation and accumulation of amyloid-β and consequently can decrease the risk of AD