***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: PURPOSE This study assessed overall quality of life of caregivers , using a path model in which burden was conceptualized as distinct from well-being . DESIGN AND METHODS Data were drawn from a representative sample of caregivers to dementia and nondementia care receivers in British Columbia , Canada ( N = 243 ) . The model used was based on a previously proposed stress/ appraisal path model and used multiple regression path estimates . Primary stressors were care receiver cognitive status , physical function , and behavioral problems ; the primary appraisal variable was hours of caregiving during the previous week . Mediators were perceived social support , frequency of getting a break , and hours of formal service use ; secondary appraisal was subjective burden . The outcome measure was generalized well-being . RESULTS Well-being was directly affected by four variables : perceived social support , burden , self-esteem , and hours of informal care . Burden was affected directly by behavioral problems , frequency of getting a break , self-esteem , and informal hours of care and was not affected by perceived social support . DISCUSSION The finding that perceived social support is strongly related to well-being but unrelated to burden reinforces the conceptual distinctiveness of the latter two concepts . This suggests that quality of life of caregivers could be improved even with burden in their lives and that the overwhelming focus in caregiving research on burden should be supplemented with an emphasis on quality of life The objective of this paper is to summarize current knowledge on the possible advantages of lifestyle interventions , with particular attention to physical fitness , cognitive activity , leisure and social activity as well as nutrition . There is a large amount of published papers providing partial evidence and asserting the need for immediate , appropriate preventive lifestyle measures against dementia and AD development . Nevertheless , there are currently great difficulties in drafting effective guidelines in this field . This depends mainly upon lack of r and omized controlled trials assessing benefits versus risks of particular lifestyle interventions strategies . However , due to the rapid increase of dementia burden , lifestyle factors and their amelioration should be already made part of decision making in light of their health-maintaining effects while awaiting for results of well- design ed large prospect i ve cohort studies in dementia Objective : To study the influence of leisure activity participation on risk of development of  amnestic mild cognitive impairment ( aMCI ) .  Methods : The authors examined the relationship between baseline level of participation in leisure activities and risk of aMCI in a prospect i ve cohort of 437 community-residing subjects older than 75 years , initially free of dementia or aMCI , using Cox analysis adjusted for age , sex , education , and chronic illnesses . The authors derived  Cognitive and Physical Activity Scales based on frequency of participation in individual activities . Results : Over a median follow-up of 5.6 years , 58 subjects had development of aMCI . A one-point increase on the Cognitive ( hazard ratio [ HR ] 0.95 , 95 % CI 0.91 to 0.99 ) but not Physical Activities Scale ( HR 0.97 , 95 % CI 0.93 to 1.01 ) was associated with lower risk of aMCI . Subjects with Cognitive Activity scores in the highest ( HR 0.46 , 95 % CI 0.24 to 0.91 ) and middle thirds ( HR 0.52 , 95 % CI 0.29 to 0.96 ) had a lower risk of aMCI compared with subjects in the lowest third . The association persisted even after excluding subjects who converted to dementia within 2 years of meeting criteria for aMCI . Conclusions : Cognitive activity participation is associated with lower risk of development of amnestic mild cognitive impairment  , even after excluding individuals at early stages of dementia BACKGROUND Participation in leisure activities has been associated with a lower risk of dementia .  It is unclear whether increased participation in leisure activities lowers the risk of dementia or participation in leisure activities declines during the pre clinical phase of dementia . METHODS We examined the relation between leisure activities and the risk of dementia in a prospect i ve cohort of 469 subjects older than 75 years of age who resided in the community and did not have dementia at base line . We examined the frequency of participation in leisure activities at enrollment and derived  cognitive-activity and physical-activity scales in which the units of measure were activity-days per week . Cox proportional-hazards analysis was used to evaluate the risk of dementia according to the base-line level of participation in leisure activities , with adjustment for age , sex , educational level , presence or absence of chronic medical illnesses , and base-line cognitive status . RESULTS Over a median follow-up period of 5.1 years ,  dementia  developed in 124 subjects ( Alzheimer 's disease in 61 subjects , vascular dementia in 30 , mixed dementia in 25 , and other types of dementia in 8) . Among leisure activities , reading , playing board games , playing musical instruments , and dancing were associated with a reduced risk of dementia . A one-point increment in the cognitive-activity score was significantly associated with a reduced risk of dementia ( hazard ratio , 0.93 [ 95 percent confidence interval , 0.90 to 0.97 ] ) , but a one-point increment in the physical-activity score was not ( hazard ratio , 1.00 ) . The association with the cognitive-activity score persisted after the exclusion of the subjects with possible pre clinical dementia at base line . Results were similar for Alzheimer 's disease and vascular dementia . In linear mixed models , increased participation in cognitive activities at base line was associated with reduced rates of decline in memory . CONCLUSIONS Participation in leisure activities is associated with a reduced risk of dementia , even after adjustment for base-line cognitive status and after the exclusion of subjects with possible pre clinical dementia . Controlled trials are needed to assess the protective effect of cognitive leisure activities on the risk of dementia 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 BACKGROUND Modifiable vascular and lifestyle-related risk factors have been associated with dementia risk in observational studies . In the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability ( FINGER ) , a proof-of-concept r and omised controlled trial , we aim ed to assess a multidomain approach to prevent cognitive decline in at-risk elderly people from the general population . METHODS In a double-blind r and omised controlled trial we enrolled individuals aged 60 - 77 years recruited from previous national surveys . Inclusion criteria were CAIDE ( Cardiovascular Risk Factors , Aging and Dementia ) Dementia Risk Score of at least 6 points and cognition at mean level or slightly lower than expected for age . We r and omly assigned participants in a 1:1 ratio to a 2 year multidomain intervention ( diet , exercise , cognitive training , vascular risk monitoring ) , or a control group ( general health advice ) . Computer-generated allocation was done in blocks of four ( two individuals r and omly allocated to each group ) at each site . Group allocation was not actively disclosed to participants and outcome assessors were masked to group allocation . The primary outcome was change in cognition as measured through comprehensive neuropsychological test battery ( NTB ) Z score . Analysis was by modified intention to treat ( all participants with at least one post-baseline observation ) . This trial is registered at Clinical Trials.gov , number NCT01041989 . FINDINGS Between Sept 7 , 2009 , and Nov 24 , 2011 , we screened 2654 individuals and r and omly assigned 1260 to the intervention group ( n=631 ) or control group ( n=629 ) . 591 ( 94 % ) participants in the intervention group and 599 ( 95 % ) in the control group had at least one post-baseline assessment and were included in the modified intention-to-treat analysis . Estimated mean change in NTB total Z score at 2 years was 0·20 ( SE 0·02 , SD 0·51 ) in the intervention group and 0·16 ( 0·01 , 0·51 ) in the control group . Between-group difference in the change of NTB total score per year was 0·022 ( 95 % CI 0·002 - 0·042 , p=0·030 ) . 153 ( 12 % ) individuals dropped out overall . Adverse events occurred in 46 ( 7 % ) participants in the intervention group compared with six ( 1 % ) participants in the control group ; the most common adverse event was musculoskeletal pain ( 32 [ 5 % ] individuals for intervention vs no individuals for control ) . INTERPRETATION Findings from this large , long-term , r and omised controlled trial suggest that a multidomain intervention could improve or maintain cognitive functioning in at-risk elderly people from the general population . FUNDING Academy of Finl and , La Carita Foundation , Alzheimer Association , Alzheimer 's Research and Prevention Foundation , Juho Vainio Foundation , Novo Nordisk Foundation , Finnish Social Insurance Institution , Ministry of Education and Culture , Salama bint Hamdan Al Nahyan Foundation , Axa Research Fund , EVO funding for University Hospitals of Kuopio , Oulu , and Turku and for Seinäjoki Central Hospital and Oulu City Hospital , Swedish Research Council , Swedish Research Council for Health , Working Life and Welfare , and af Jochnick Foundation CONTEXT Dementia is common , costly , and highly age related . Little attention has been paid to the identification of modifiable lifestyle habits for its prevention . OBJECTIVE To explore the association between physical activity and the risk of cognitive impairment and dementia .  DESIGN , SETTING , AND SUBJECTS Data come from a community sample of 9008 r and omly selected men and women 65 years or older , who were evaluated in the 1991 - 1992 Canadian Study of Health and Aging , a prospect i ve cohort study of dementia . Of the 6434 eligible subjects who were cognitively normal at baseline , 4615 completed a 5-year follow-up .  Screening and clinical evaluations were done at both waves of the study . In 1996 - 1997 , 3894 remained without cognitive impairment , 436 were diagnosed as having cognitive impairment-no dementia , and 285 were diagnosed as having dementia . MAIN OUTCOME MEASURE Incident cognitive impairment and dementia by levels of physical activity at baseline . RESULTS Compared with no exercise , physical activity was associated with lower risks of cognitive impairment , Alzheimer disease , and dementia of any type . Significant trends for increased protection with greater physical activity were observed . High levels of physical activity were associated with reduced risks of cognitive impairment ( age- , sex- , and education-adjusted odds ratio , 0.58 ; 
    Output:
    
CONCLUSIONS While the findings support a growing consensus that participation in leisure activities might significantly contribute to prevention of dementia , it also identifies major hindrances to progress .