***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: The circulating level of brain-derived neurotrophic factor ( BDNF ) is reduced in patients with major depression and type-2 diabetes . Because acute exercise increases BDNF production in the hippocampus and cerebral cortex , we hypothesized that endurance training would enhance the release of BDNF from the human brain as detected from arterial and internal jugular venous blood sample s. In a r and omized controlled study , 12 healthy sedentary males carried out 3 mo of endurance training ( n = 7 ) or served as controls ( n = 5 ) . Before and after the intervention ,  blood sample s were obtained at rest and during exercise . At baseline , the training group ( 58 + or - 106 ng x 100 g(-1 ) x min(-1 ) , means + or - SD ) and the control group ( 12 + or - 17 ng x 100 g(-1 ) x min(-1 ) ) had a similar release of BDNF from the brain at rest . Three months of endurance training enhanced the resting release of BDNF to 206 + or - 108 ng x 100 g(-1 ) x min(-1 ) ( P < 0.05 ) , with no significant change in the control subjects , but there was no training-induced increase in the release of BDNF during exercise . Additionally , eight mice completed a 5-wk treadmill running training protocol that increased the BDNF mRNA expression in the hippocampus ( 4.5 + or - 1.6 vs. 1.4 + or - 1.1 mRNA/ssDNA ; P < 0.05 ) , but not in the cerebral cortex ( 4.0 + or - 1.4 vs. 4.6 + or - 1.4 mRNA/ssDNA ) compared with untrained mice . The increased BDNF expression in the hippocampus and the enhanced release of BDNF from the human brain following training suggest that endurance training promotes brain health CONTEXT Many observational studies have shown that physical activity reduces the risk of cognitive decline ; however , evidence from r and omized trials is lacking . OBJECTIVE To determine whether physical activity reduces the rate of cognitive decline among older adults at risk . DESIGN AND SETTING R and omized controlled trial of a 24-week physical activity intervention conducted between 2004 and 2007 in metropolitan Perth , Western Australia . Assessors of cognitive function were blinded to group membership . PARTICIPANTS We recruited volunteers who reported memory problems but did not meet criteria for dementia . Three hundred eleven individuals aged 50 years or older were screened for eligibility , 89 were not eligible , and 52 refused to participate . A total of 170 participants were r and omized and 138 participants completed the 18-month assessment . INTERVENTION Participants were r and omly allocated to an education and usual care group or to a 24-week home-based program of physical activity . MAIN OUTCOME MEASURE Change in Alzheimer Disease Assessment Scale-Cognitive Subscale ( ADAS-Cog ) scores ( possible range , 0 - 70 ) over 18 months . RESULTS In an intent-to-treat analysis , participants in the intervention group improved 0.26 points ( 95 % confidence interval , -0.89 to 0.54 ) and those in the usual care group deteriorated 1.04 points ( 95 % confidence interval , 0.32 to 1.82 ) on the ADAS-Cog at the end of the intervention . The absolute difference of the outcome measure between the intervention and control groups was -1.3 points ( 95 % confidence interval,-2.38 to -0.22 ) at the end of the intervention . At 18 months , participants in the intervention group improved 0.73 points ( 95 % confidence interval , -1.27 to 0.03 ) on the ADAS-Cog , and those in the usual care group improved 0.04 points ( 95 % confidence interval , -0.46 to 0.88 ) . Word list delayed recall and Clinical Dementia Rating sum of boxes improved modestly as well , whereas word list total immediate recall , digit symbol coding , verbal fluency , Beck depression score , and Medical Outcomes 36-Item Short-Form physical and mental component summaries did not change significantly . CONCLUSIONS In this study of adults with subjective memory impairment , a 6-month program of physical activity provided a modest improvement in cognition over an 18-month follow-up period . TRIAL REGISTRATION anzctr.org.au Identifier : ACTRN12605000136606 Background To examine the effect of multicomponent exercise program on memory function in older adults with mild cognitive impairment ( MCI ) , and identify biomarkers associated with improvement of cognitive functions . Methodology /Principal Findings Subjects were 100 older adults ( mean age , 75 years ) with MCI . The subjects were classified to an amnestic MCI group ( n = 50 ) with neuroimaging measures , and other MCI group ( n = 50 ) before the r and omization . Subjects in each group were r and omized to either a multicomponent exercise or an education control group using a ratio of 1∶1 . The exercise group exercised for 90 min/d , 2 d/wk , 40 times for 6 months . The exercise program was conducted under multitask conditions to stimulate attention and memory . The control group attended two education classes . A repeated- measures ANOVA revealed that no group × time interactions on the cognitive tests and brain atrophy in MCI patients . A sub- analysis of amnestic MCI patients for group × time interactions revealed that the exercise group exhibited significantly better Mini-Mental State Examination ( p = .04 ) and logical memory scores ( p = .04 ) , and reducing whole brain cortical atrophy ( p<.05 ) compared to the control group . Low total cholesterol levels before the intervention were associated with an improvement of logical memory scores ( p<.05 ) , and a higher level of brain-derived neurotrophic factor was significantly related to improved ADAS-cog scores ( p<.05 ) . Conclusions / Significance The results suggested that an exercise intervention is beneficial for improving logical memory and maintaining general cognitive function and reducing whole brain cortical atrophy in older adults with amnestic MCI . Low total cholesterol and higher brain-derived neurotrophic factor may predict improvement of cognitive functions in older adults with MCI . Further studies are required to determine the positive effects of exercise on cognitive function in older adults with MCI . Trial Registration UMIN-CTR UMIN000003662 ctr.cgi?function = brows&action = brows&type = summary & recptno = R000004436 & language = Objective : To examine the effects of aerobic exercise or vitamin B supplementation on cognitive function in older adults with mild cognitive impairment ( MCI ) . Design : R and omised placebo-controlled trial . Setting : General community . Participants : Community-dwelling adults aged 70–80 with MCI . Interventions : The 152 participants were r and omly assigned to two interventions : ( 1 ) a twice-weekly , group-based , moderate-intensity walking programme ( WP , n = 77 ) or a low-intensity placebo activity programme ( n = 75 ) for one year ; and ( 2 ) daily vitamin pill containing 5 mg folic acid , 0.4 mg vitamin B-12 , 50 mg vitamin B-6 ( FA/B12/B6 , n = 78 ) or placebo pill ( n = 74 ) for one year . Outcome measures : Cognitive function , measured with neuropsychological tests at baseline and after six and 12 months . Results : Median session attendance at the exercise programmes ( 25th–75th percentile ) was 63 % ( 2%–81 % ) and median compliance with taking pills ( 25th–75th percentile ) was 100 % ( 99%–100 % ) . Gender was an effect modifier . Intention-to-treat analysis revealed no main intervention effect for either intervention . In women in the WP , attention ( Stroop combination task ) improved by 0.3 seconds ( p = 0.04 ) and memory ( auditory verbal learning test ) by 0.04 words ( p = 0.06 ) with each percentage increase in session attendance . In men attending at least 75 % of the sessions , the WP improved memory ( β 1.5 ( 95 % CI : 0.1 to 3.0 ) words ) . Conclusion : The walking programme and /or FA/B12/B6 supplementation were not effective in improving cognition within one year . The walking programme , however , was efficacious in improving memory in men and memory and attention in women with better adherence . Trial registration : International St and ard R and omised Controlled Trial Number Register , 19227688 , http://www.controlled-trials.com/is rct The hippocampus shrinks in late adulthood , leading to impaired memory and increased risk for dementia . Hippocampal and medial temporal lobe volumes are larger in higher-fit adults , and physical activity training increases hippocampal perfusion , but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown . Here we show , in a r and omized controlled trial with 120 older adults , that aerobic exercise training increases the size of the anterior hippocampus , leading to improvements in spatial memory .  Exercise training increased hippocampal volume by 2 % , effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF , a mediator of neurogenesis in the dentate gyrus . Hippocampal volume declined in the control group , but higher preintervention fitness partially attenuated the decline , suggesting that fitness protects against volume loss . Cau date nucleus and thalamus volumes were unaffected by the intervention . These theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood , which is accompanied by improved memory function OBJECTIVE the aim of this study was to compare the effects of a functional tasks exercise programme to a cognitive training programme in older adults with mild cognitive impairment . DESIGN a single-blind r and omised control trial with the intervention group compared with an active control group . SETTING out-patient clinic . PARTICIPANTS older adults with mild cognitive impairment ( n = 83 ) aged 60 and older living in the community . METHODS participants were r and omised to either a functional task exercise group ( n = 43 ) or an active cognitive training group ( n = 40 ) for 10 weeks . All outcome measures were undertaken at baseline , post-intervention and 6-month follow-up using Neurobehavioral Cognitive Status Examination , Trail Making Test , Chinese Version Verbal Learning Test , Category Verbal Learning Test , Lawton Instrumental Activities of Daily Living Scale and Problems in Everyday Living Test . RESULTS the functional task exercise group showed significant between-group differences in general cognitive functions , memory , executive function , functional status and everyday problem solving ability . The improvements were sustained over time at 6-month follow-up . CONCLUSION a functional tasks exercise programme is feasible for improving cognitive functions and functional status of older adults with mild cognitive impairment . This may serve as a cost-effective adjunct to the existing interventions for population s with mild cognitive impairment . TRIAL REGISTRATION NUMBER ACTRN12610001025022 Impaired glucose regulation is a defining characteristic of type 2 diabetes mellitus ( T2DM ) pathology and has been linked to increased risk of cognitive impairment and dementia . Although the benefits of aerobic exercise for physical health are well-documented , exercise effects on cognition have not been examined for older adults with poor glucose regulation associated with prediabetes and early T2DM . Using a r and omized controlled design , twenty-eight adults ( 57 - 83 y old ) meeting 2-h tolerance test criteria for glucose intolerance completed 6 months of aerobic exercise or stretching  , which served as the control . The primary cognitive outcomes included measures of executive function ( Trails B , Task Switching , Stroop , Self-ordered Pointing Test , and Verbal Fluency ) . Other outcomes included memory performance ( Story Recall , List Learning ) , measures of cardiorespiratory fitness obtained via maximal- grade d exercise treadmill test , glucose disposal during hyperinsulinemic-euglycemic clamp , body fat , and fasting plasma levels of insulin , cortisol , brain-derived neurotrophic factor , insulin-like growth factor-1 , amyloid-β ( Aβ40 and Aβ42 ) . Six months of aerobic exercise  improved executive function ( MANCOVA , p=0.04 ) , cardiorespiratory fitness ( MANOVA , p=0.03 ) , and insulin sensitivity ( p=0.05 ) . Across all subjects , 6-month changes in cardiorespiratory fitness and insulin sensitivity were positively correlated ( p=0.01 ) . For Aβ42 , plasma levels tended to decrease for the aerobic group relative to controls ( p=0.07 ) . The results of our study using rigorous controlled methodology suggest a cognition-enhancing effect of aerobic exercise for older glucose intolerant adults . Although replication in a larger sample is needed , our findings potentially have important therapeutic implication s for a growing number of adults at increased risk of cognitive decline OBJECTIVES To apply diagnostic criteria for mild cognitive impairment ( M 
    Output:
    
Results indicated that physical exercise may benefit cognitive function among older adults who have MCI , including improvements in global cognition , executive function , memory , attention , and processing speed .
Physical exercise may also positively impact the physiology of the aging brain .