***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 a small number of reports exist on the cognitive effects of soy isoflavones , the findings from which are mixed . Isoflavone efficacy is dependent upon conversion of glycosides contained in soy foods and supplements to the biologically active aglycons . Of particular interest is the production of the metabolite , equol , which is dependent upon intestinal microflora and an integrous digestive system , both being altered by age and age-associated conditions . Unfortunately , few studies enrolled adults over the age of 70 , and none included older men . OBJECTIVE we examined safety , feasibility and cognitive efficacy of soy isoflavone administration in older nondemented men and women ( age 62 - 89 years ) . DESIGN AND METHODS in this r and omised , placebo-controlled , double-blind pilot study , subjects ingested either 100 mg/day soy isoflavones ( glycoside weight ) or matching placebo tablets for 6 months . RESULTS active and placebo-treated subjects exhibited a comparable side-effect profile . Plasma levels of genistein and daidzein ( P < 0.001 ) , but not equol , increased with isoflavone administration . While similar at baseline , the two groups differed across 6 months of treatment on 8 of 11 cognitive tests administered . Isoflavone-treated subjects improved on tests of visual-spatial memory ( P < 0.01 ) and construction ( P = 0.01 ) , verbal fluency ( P < 0.01 ) and speeded dexterity ( P = 0.04 ) . Placebo-treated participants were faster than isoflavone-treated subjects on two tests of executive function ( P < 0.05 ) . CONCLUSIONS these data suggest that administration of 100 mg/day of isoflavones was well tolerated . Plasma genistein and daidzein levels , but not equol , increased with isoflavone administration . Finally , data support the potential cognitive effects of soy isoflavones in older adults Females perform better in certain memory-related tasks than males . Sex differences in cognitive performance may be attributable to differences in circulating oestrogen acting on oestrogen beta receptors ( ERbeta ) which are prevalent in brain regions such as the hippocampus , frontal lobe and cortex that mediate cognitive functions . Since soya isoflavones are known to activate ERbeta , chronic isoflavone supplementation in males may improve cognitive performance in memory-related tasks . A 12-week double-blind , placebo-controlled cross-over trial was conducted in thirty-four healthy men to investigate the effect of isoflavone supplementation on cognitive function .  Volunteers were r and omised to take four capsules/d containing soya isoflavones ( 116 mg isoflavone equivalents/d : 68 mg daidzein , 12 mg genistein , 36 mg glycitin ) or placebo for 6 weeks , and the alternate treatment during the following 6 weeks . Assessment s of memory ( verbal episodic , auditory and working ) , executive function ( planning , attention , mental flexibility ) and visual-spatial processing were performed at baseline and after each treatment period . Isoflavone supplementation significantly improved spatial working memory ( P = 0.01 ) , a test in which females consistently perform better than males . Compared with placebo supplementation , there were 18 % fewer attempts ( P = 0.01 ) , 23 % fewer errors ( P = 0.02 ) and 17 % less time ( P = 0.03 ) required to correctly identify the requisite information . Isoflavones did not affect auditory and episodic memory ( Paired Associate Learning , Rey 's Auditory Verbal Learning Task , Backward Digit Span and Letter-Number Sequencing ) , executive function ( Trail Making and Initial Letter Fluency Task ) or visual-spatial processing ( Mental Rotation Task ) .  Isoflavone supplementation in healthy males may enhance cognitive processes which appear dependent on oestrogen activation BACKGROUND The many putative beneficial effects of the polyphenol resveratrol include an ability to bolster endogenous antioxidant defenses , modulate nitric oxide synthesis , and promote vasodilation , which thereby improves blood flow . Resveratrol may therefore modulate aspects of brain function in humans . OBJECTIVE The current study assessed the effects of oral resveratrol on cognitive performance and localized cerebral blood flow variables in healthy human adults . DESIGN In this r and omized , double-blind , placebo-controlled , crossover study , 22 healthy adults received placebo and 2 doses ( 250 and 500 mg ) of trans-resveratrol in counterbalanced order on separate days . After a 45-min resting absorption period , the participants performed a selection of cognitive tasks that activate the frontal cortex for an additional 36 min . Cerebral blood flow and hemodynamics , as indexed by concentration changes in oxygenated and deoxygenated hemoglobin , were assessed in the frontal cortex throughout the posttreatment period with the use of near-infrared spectroscopy . The presence of resveratrol and its conjugates in plasma was confirmed by HPLC after the same doses in a separate cohort ( n = 9 ) . RESULTS Resveratrol administration result ed in dose-dependent increases in cerebral blood flow during task performance , as indexed by total concentrations of hemoglobin . There was also an increase in deoxyhemoglobin after both doses of resveratrol , which suggested enhanced oxygen extraction , that became apparent toward the end of the 45-min absorption phase and was sustained throughout task performance . Cognitive function was not affected . Resveratrol metabolites were present in plasma throughout the cognitive task period . CONCLUSION These results showed that single doses of orally administered resveratrol can modulate cerebral blood flow variables CONTEXT Postmenopausal women have a greater risk than men of developing Alzheimer disease , but studies of the effects of estrogen therapy on Alzheimer disease have been inconsistent . On July 8 , 2002 , the study drugs , estrogen plus progestin , in the Women 's Health Initiative ( WHI ) trial were discontinued because of certain increased health risks in women receiving combined hormone therapy . OBJECTIVE To evaluate the effect of estrogen plus progestin on the incidence of dementia and mild cognitive impairment compared with placebo . DESIGN , SETTING , AND PARTICIPANTS The Women 's Health Initiative Memory Study ( WHIMS ) , a r and omized , double-blind , placebo-controlled clinical trial , began enrolling participants from the Women 's Health Initiative ( WHI ) estrogen plus progestin trial in May 1996 . Of the 4894 eligible participants of the WHI study , 4532 ( 92.6 % ) postmenopausal women free of probable dementia , aged 65 years or older , and recruited from 39 of 40 WHI clinical centers were enrolled in the WHIMS . INTERVENTION Participants received either 1 daily tablet of 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate ( n = 2229 ) , or a matching placebo ( n = 2303 ) . MAIN OUTCOME MEASURES Incidence of probable dementia ( primary outcome ) and mild cognitive impairment ( secondary outcome ) were identified through a structured clinical assessment . RESULTS The mean ( SD ) time between the date of r and omization into WHI and the last Modified Mini-Mental State Examination ( 3MSE ) for all WHIMS participants was 4.05 ( 1.19 ) years . Overall , 61 women were diagnosed with probable dementia , 40 ( 66 % ) in the estrogen plus progestin group compared with 21 ( 34 % ) in the placebo group . The hazard ratio ( HR ) for probable dementia was 2.05 ( 95 % confidence interval [ CI ] , 1.21 - 3.48 ; 45 vs 22 per 10 000 person-years ; P = .01 ) . This increased risk would result in an additional 23 cases of dementia per 10 000 women per year . Alzheimer disease was the most common classification of dementia in both study groups . Treatment effects on mild cognitive impairment did not differ between groups ( HR , 1.07 ; 95 % CI , 0.74 - 1.55 ; 63 vs 59 cases per 10 000 person-years ; P = .72 ) . CONCLUSIONS Estrogen plus progestin therapy increased the risk for probable dementia in postmenopausal women aged 65 years or older . In addition , estrogen plus progestin therapy did not prevent mild cognitive impairment in these women . These findings , coupled with previously reported WHI data , support the conclusion that the risks of estrogen plus progestin outweigh the benefits Previous research has shown that resveratrol can increase cerebral blood flow ( CBF ) in the absence of improved cognitive performance in healthy , young human subjects during the performance of cognitively dem and ing tasks . This lack of cognitive effects may be due to low bioavailability and , in turn , reduced bioefficacy of resveratrol in vivo . Piperine can alter polyphenol pharmacokinetics , but previous studies have not investigated whether this affects the efficacy of the target compound . Therefore , the objective of the present study was to ascertain whether co-supplementation of piperine with resveratrol affects the bioavailability and efficacy of resveratrol  with regard to cognition and CBF . The present study utilised a r and omised , double-blind , placebo-controlled , within-subjects design , where twenty-three adults were given placebo , trans-resveratrol ( 250 mg ) and trans-resveratrol with 20 mg piperine on separate days at least a week apart . After a 40 min rest/absorption period , the participants performed a selection of cognitive tasks and CBF was assessed throughout the period , in the frontal cortex , using near-IR spectroscopy . The presence of resveratrol and its conjugates in the plasma was confirmed by liquid chromatography-MS analysis carried out following the administration of the same doses in a separate cohort ( n 6 ) . The results indicated that when co-supplemented , piperine and resveratrol significantly augmented CBF during task performance in comparison with placebo and resveratrol alone . Cognitive function , mood and blood pressure were not affected . The plasma concentrations of resveratrol and its metabolites were not significantly different between the treatments , which indicates that co-supplementation of piperine with resveratrol enhances the bioefficacy of resveratrol with regard to CBF effects , but not cognitive performance , and does this without altering bioavailability RATIONALE The decline in estrogen concentrations in women after menopause can contribute to health related changes including impairments in cognition , especially memory . Because of the health concerns related to hormone replacement therapy ( HRT ) , alternative approaches to treat menopausal symptoms , such as nutritional supplements and /or diet containing isoflavones , are of interest . OBJECTIVES This study investigated whether soy isoflavones ( soy milk and supplement ) could improve cognitive functioning in healthy , postmenopausal women . PARTICIPANTS , INTERVENTION AND DESIGN : A total of 79 postmenopausal women , 48 - 65 years of age , completed a double-blind , placebo-controlled trial in which they were r and omly assigned to one of three experimental groups : cow 's milk and a placebo supplement ( control ) ; soy milk and placebo supplement ( soy milk , 72 mg isoflavones/day ) ; or cow 's milk and isoflavone supplement ( isoflavone supplement , 70 mg isoflavones/day ) . MEASUREMENTS Cognitive functioning was assessed using various cognitive tasks before the intervention ( baseline ) and after the intervention ( test ) . RESULTS In contrast to predictions , soy isoflavones did not improve selective attention ( Stroop task ) , visual long-term memory ( pattern recognition ) , short-term visuospatial memory ( Benton Visual Retention Test ) , or visuo-spatial working memory ( color match task ) . Also , the soy milk group showed a decline in verbal working memory ( Digit Ordering Task ) compared to the soy supplement and control groups . CONCLUSION Soy isoflavones consumed as a food or supplement over a 16-week period did not improve or appreciably affect cognitive functioning in healthy , postmenopausal women Objective : To investigate whether soy-derived isoflavone extract improves performance in cognitive function and quality of life in Chinese postmenopausal women . Design : The study was a 6-month double-blind , r and omized , placebo-controlled , parallel group trial . Participants were community-dwelling women aged 55 to 76 years ; 191 eligible women were r and omly assigned to receive a daily oral intake of 80 mg soy-derived isoflavones or an identical-appearing placebo for 6 months . St and ardized neuropsychological tests of memory , executive function , attention , motor control , language , and visual perception and a global cognitive function assessment were administered face-to-face individually at baseline and at 6-months posttreatment . The vali date d Chinese version of the Short Form-36 was used for quality of life measurements . Results : Of the participants , 88 % ( 168 women : 80 among the supplementation group and 88 among the placebo group ) completed the trial . Intention-to-treat analysis , conducted for 17 
    Output:
    
The cognitive benefit of resveratrol was related to improved cerebral perfusion