An increasing body of evidence suggests that health behaviors may protect against cognitive impairment and dementia. The purpose of this study was to summarize the current evidence on health behavioral factors predicting cognitive health through a systematic review of the published literature. PubMed, Embase, and PsycINFO databases were searched for studies on community representative samples aged 65 and older, with prospective cohort design and multivariate analysis. The outcome--cognitive health--was defined as a continuum of cognitive function ranging from cognitive decline to impairment and dementia, and health behaviors included physical activity, smoking, alcohol drinking, body mass index, and diet and nutrition. Of 12,105 abstracts identified, 690 relevant full-texts were reviewed. The final yield amounted to 115 articles of which 37 studies were chosen that met the highest standards of quality. Leisure time physical activity, even of moderate level, showed protective effects against dementia, whereas smoking elevated the risk of Alzheimer's disease. Moderate alcohol consumption tended to be protective against cognitive decline and dementia, but nondrinkers and frequent drinkers exhibited a higher risk for dementia and cognitive impairment. Midlife obesity had an adverse effect on cognitive function in later life. Analysis showed vegetable and fish consumption to be of benefit, whereas, persons consuming a diet high in saturated fat had an increased dementia risk. The review demonstrates accumulating evidence supporting health behavioral effects in reducing the risk of cognitive decline and dementia. Results indicate potential benefits of healthy lifestyles in protecting cognitive health in later life.

Background: Subcortical vascular dementia (SVaD) is considered the most common type of vascular dementia and often follows a slowly progressive course, simulating Alzheimer disease (AD). Whether the progressive cognitive decline is associated with pure SVaD or concomitant AD remains unknown. The purpose of this study was to determine what proportion of patients with SVaD lack abnormal amyloid imaging, and to examine differences in the clinical or MRI features between subjects with SVaD with cortical amyloid deposition and those without. Methods: We measured brain amyloid deposition using ¹¹C-Pittsburgh compound B (PiB) PET in 45 patients (men: women = 19:26; mean age 74.2 ± 7.6 years) with SVaD. They all met DSM-IV criteria for vascular dementia and had severe white matter high signal intensities without territorial infarction or macrohemorrhage on MRI. Results: Thirty-one (68.9%) of 45 patients with SVaD were negative for cortical PiB binding. There was significant difference between ¹¹C-PiB-positive and ¹¹C-PiB-negative groups in terms of age (79.5 vs 71.9 years), Mini-Mental State Examination score (18.6 vs 22.6), the number of lacunes (3.9 vs 9.0), and the visual rating scale of hippocampal atrophy (3.1 vs 2.3). The neuropsychological assessments revealed that patients with ¹¹C-PiB-negative SVaD performed better on the delayed recall of both the verbal and visual memory test than did those with ¹¹C-PiB-positive scan. Conclusion: SVaD without abnormal amyloid imaging was more common than expected. Patients with SVaD with and without abnormal amyloid imaging differed in clinical and MRI features, although there was considerable overlap.

Background: This study was performed to better assess the perceptions, motivating factors, and behaviors associated with the use of hand washing to prevent H1N1 influenza transmission during the peak pandemic period in Korea.Methods: A cross-sectional survey questionnaire was completed by 942 students at a university campus in Suwon, Korea, between December 1 and 8, 2009. The survey included questions regarding individual perceptions, motivating factors, and behaviors associated with hand washing for the prevention of H1N1 influenza transmission.Results: Compared to one year prior, 30.3% of participants reported increasing their hand washing frequency. Female students were more likely to practice more frequent hand washing. Women also perceived the effectiveness of hand washing to be lower, and illness severity and personal susceptibility to H1N1 infection to be higher. Study participants who were female (OR: 1.79-3.90) who perceived of hand washing to be effective (OR: 1.34-12.15) and illness severity to be greater (OR: 1.00-3.12) washed their hands more frequently.Conclusions: Korean students increased their frequency of hand hygiene practices during the pandemic, with significant gender differences existing in the attitudes and behaviors related to the use of hand hygiene as a means of disease prevention. Here, the factors that affected hand washing behavior were similar to those identified at the beginning of the H1N1 or SARS pandemics, suggesting that public education campaigns regarding hand hygiene are effective in altering individual hand hygiene habits during the peak periods of influenza transmission.

Volatile organic compounds (VOCs) are reported to cause adverse effects on pulmonary function in occupationally exposed workers. However, evidence is lacking on the effect in the general population. We hypothesised that VOCs impair pulmonary function through enhancing oxidative stress, especially in the elderly population.A longitudinal panel study of 154 elderly people was performed in South Korea. Repeated spirometric tests were performed up to eight times on different days for each subject. We also measured urinary concentrations of metabolites of the VOC and markers of oxidative stress (malondialdehyde and 8-oxo-2′-deoxyguanosine) on the same day of spirometric tests. A mixed linear regression model was used to evaluate the association among the VOC metabolites, oxidative stress markers and spirometric tests.We found that the urinary levels of hippuric acid and methylhippuric acid, which are metabolites of toluene and xylene, respectively, were significantly associated with reduction of forced expiratory volume in 1 s (FEV₁), FEV₁/forced vital capacity (FVC), and forced expiratory flow at 25–75% of FVC. We also found significant associations between the metabolites of VOCs and the markers of oxidative stress. In addition, the oxidative stress markers were associated with pulmonary function parameters.This study suggests that exposure to toluene and xylene exert a harmful effect on pulmonary function by exacerbating oxidative stress in elderly people.