Alcohol consumption as a risk factor for dementia and cognitive decline: meta-analysis of prospective studies

Alcohol consumption patterns and cognitive impairment in older women

OBJECTIVE

Few studies have investigated changes in alcohol consumption and risk of cognitive impairment among oldest old adults.

METHODS

In a prospective study of 1309 women ≥65 years old, alcohol use was assessed at repeated visits and used to estimate average change in alcohol consumption over 16 years. Clinically significant cognitive impairment (mild cognitive impairment and dementia) was assessed at year 20.

RESULTS

Compared with the reference group (slight decrease in alcohol consumption by 0-0.5 drinks/week, 60.4%), increasing consumption over time (>0 drinks/week) was not associated with risk of cognitive impairment (5.0%, odds ratio [OR]: 1.00, 95% confidence interval [CI]: 0.54-1.85). Decreasing consumption by >0.5 drinks/week was associated with increased risk (34.5%, OR: 1.34, 95% CI: 1.05-1.70). Adjustment for age, education, diabetes, smoking, BMI, and physical activity attenuated the magnitude of the effect slightly and resulted in borderline statistical significance.

CONCLUSION

Women in their ninth and tenth decade of life who decrease alcohol use may be at risk of cognitive impairment.

Three midlife strategies to prevent cognitive impairment due to Alzheimer's disease

The slow, progressive accumulation of pathology characteristic of Alzheimer's disease is the principal determinant of cognitive decline leading to dementia. Risk-reduction strategies during midlife focus on raising the clinical threshold for the appearance of cognitive symptoms and on reducing the extent of Alzheimer pathology. Best available evidence suggests an approach based on three, conceptually distinct strategies. (1) Raise the threshold for cognitive symptoms by improving brain health. To achieve this goal, the tactic is to reduce cerebrovascular risks mediated by hypertension, diabetes, cigarette smoking, and hyperlipidemia. (2) Raise the threshold for cognitive symptoms by enhancing cognitive reserve. Here, tactics focus on mental stimulation associated with occupation, leisure activities and social engagement. (3) Reduce the burden of Alzheimer pathology. The most promising tactic toward this end is regular aerobic exercise. Tactics in support of strategies to reduce cognitive impairment due to Alzheimer pathology are not yet substantiated by robust, consistent clinical trial evidence. There is pressing need for well-designed pragmatic trials to provide stronger evidence on preventive strategies for late-life cognitive decline and dementia.

History of alcohol use disorders and risk of severe cognitive impairment: a 19-year prospective cohort study

OBJECTIVE

To assess the effects of a history of alcohol use disorders (AUDs) on risk of severe cognitive and memory impairment in later life.

METHODS

We studied the association between history of AUDs and the onset of severe cognitive and memory impairment in 6,542 middle-aged adults born 1931 through 1941 who participated in the Health and Retirement Study, a prospective nationally representative U.S. cohort. Participants were assessed at 1992 baseline and follow-up cognitive assessments were conducted biannually from 1996 through 2010. History of AUDs was identified using the three-item modified CAGE questionnaire. Cognitive outcomes were assessed using the 35-item modified Telephone Interview for Cognitive Status at last follow-up with incident severe cognitive impairment defined as a score ≤ 8, and incident severe memory impairment defined as a score ≤ 1 on a 20-item memory subscale.

RESULTS

During up to 19 years of follow-up (mean: 16.7 years, standard deviation: 3.0, range: 3.5-19.1 years), 90 participants experienced severe cognitive impairment and 74 participants experienced severe memory impairment. History of AUDs more than doubled the odds of severe memory impairment (odds ratio [OR] = 2.21, 95% confidence interval [CI] = 1.27-3.85, t = 2.88, df = 52, p = 0.01). The association with severe cognitive impairment was statistically non-significant but in the same direction (OR = 1.80, 95% CI = 0.97-3.33, t = 1.92, df = 52, p = 0.06).

CONCLUSION

Middle-aged adults with a history of AUDs have increased odds of developing severe memory impairment later in life. These results reinforce the need to consider the relationship between alcohol consumption and cognition from a multifactorial lifespan perspective.

Effects of alcohol consumption on cognition and regional brain volumes among older adults

This study utilized data from the Framingham Heart Study Offspring Cohort to examine the relationship between midlife and late-life alcohol consumption, cognitive functioning, and regional brain volumes among older adults without dementia or a history of abusing alcohol. The results from multiple linear regression models indicate that late life, but not midlife, alcohol consumption status is associated with episodic memory and hippocampal volume. Compared to late life abstainers, moderate consumers had larger hippocampal volume, and light consumers had higher episodic memory. The differences in episodic memory according to late life alcohol consumption status were no longer significant when hippocampal volume was included in the regression model. The findings from this study provide new evidence that hippocampal volume may contribute to the observed differences in episodic memory among older adults and late life alcohol consumption status.

Alcohol consumption and cognitive performance: a Mendelian randomization study

AIMS

To use Mendelian randomization to assess whether alcohol intake was causally associated with cognitive function.

DESIGN

Mendelian randomization using a genetic variant related to alcohol intake (ADH1B rs1229984) was used to obtain unbiased estimates of the association between alcohol intake and cognitive performance.

SETTING

Europe.

PARTICIPANTS

More than 34 000 adults.

MEASUREMENTS

Any versus no alcohol intake and units of intake in the previous week was measured by questionnaire. Cognitive function was assessed in terms of immediate and delayed word recall, verbal fluency and processing speed.

FINDINGS

Having consumed any versus no alcohol was associated with higher scores by 0.17 standard deviations (SD) [95% confidence interval (CI) = 0.15, 0.20] for immediate recall, 0.17 SD (95% CI = 0.14, 0.19) for delayed recall, 0.17 SD (95% CI = 0.14, 0.19) for verbal fluency and 0.12 SD (95% CI = 0.09, 0.15) for processing speed. The minor allele of rs1229984 was associated with reduced odds of consuming any alcohol (odds ratio = 0.87; 95% CI = 0.80, 0.95; P = 0.001; R(2)  = 0.1%; F-statistic = 47). In Mendelian randomization analysis, the minor allele was not associated with any cognitive test score, and instrumental variable analysis suggested no causal association between alcohol consumption and cognition: -0.74 SD (95% CI = -1.88, 0.41) for immediate recall, -1.09 SD (95% CI = -2.38, 0.21) for delayed recall, -0.63 SD (95% CI = -1.78, 0.53) for verbal fluency and -0.16 SD (95% CI = -1.29, 0.97) for processing speed.

CONCLUSIONS

The Mendelian randomization analysis did not provide strong evidence of a causal association between alcohol consumption and cognitive ability.

Risk Factors Related to Cognitive Functioning: A Cross-National Comparison of U.S. and Korean Older Adults

The purpose of this study was to conduct a cross-national comparison of factors related to cognitive functioning in later life in a U.S. and Korean sample. The study sample was comprised of subjects from the HRS ( N = 10,175) and the KLoSA ( N = 3,550). Separate multivariate regression models were employed to examine the impact of socio-demographic, health, and health behaviors on cognitive functioning among older adults. Regression results showed that age, gender, education, wealth, self-rated health, ADL, IADL, stroke, and poor eyesight were significantly associated with cognitive functioning in both countries. However, depression, high blood pressure, diabetes, and drinking were significantly associated with cognition only among Americans, while marital status and poor hearing were significantly associated with cognition only among Koreans. In addition, gender-specific models suggested several socio-economic and health factors had significantly different effects by gender in both countries. Cross-national comparative research identified similar risk factors, suggesting robust associations. Unique factors related to cognitive functioning in U.S. and Korean older adults highlight the important role of societal influences on cognitive outcomes.

Increased risk of dementia in patients exposed to nitrogen dioxide and carbon monoxide: a population-based retrospective cohort study

Background

The air pollution caused by vehicular emissions is associated with cognitive decline. However, the associations between the levels of nitrogen dioxide (NO₂) and carbon monoxide (CO) exposure and dementia remain poorly defined and have been addressed in only a few previous studies.

Materials and Methods

In this study, we obtained data on 29547 people from the National Health Insurance Research Database (NHIRD) of Taiwan, including data on 1720 patients diagnosed with dementia between 2000 and 2010, and we evaluated the risk of dementia among four levels of air pollutant. Detailed data on daily air pollution were available from January 1, 1998 to December 31, 2010. Yearly average concentrations of pollutants were calculated from the baseline to the date of dementia occurrence, withdrawal of patients, or the end of the study, and these data were categorized into quartiles, with Q1 being the lowest level and Q4 being the highest.

Results

In the case of NO₂, the adjusted hazard ratios (HRs) of dementia for all participants in Q2, Q3, and Q4 compared to Q1 were 1.10 (95% confidence interval (CI), 0.96–1.26), 1.01 (95% CI, 0.87–1.17), and 1.54 (95% CI, 1.34–1.77), and in the case of CO, the adjusted HRs were 1.07 (95% CI, 0.92–1.25), 1.37 (95% CI, 1.19–1.58), and 1.61 (95% CI, 1.39–1.85).

Conclusion

The results of this large retrospective, population-based study indicate that exposure to NO₂ and CO is associated with an increased risk of dementia in the Taiwanese population.

Life-course socio-economic disadvantage and late-life cognitive functioning in Taiwan: results from a national cohort study

BACKGROUND

Declines in late-life cognitive functioning differ greatly between socio-economic status (SES) groups, but little is known about whether these effects are related to child and adult SES versus SES effects that accumulate over the individual's life course.

METHODS

An 18-year longitudinal national sample of older adults from Taiwan (n=2944) was used to estimate the effect of socio-economic disadvantage over the individual's life course on cognitive functioning during late life. Cognitive functioning was assessed using the brief Short Portable Mental Status Questionnaire scale. Life-course socio-economic disadvantage, as accrued during childhood and adulthood, included measures of paternal education and occupation and participant's education and occupation.

RESULTS

Multivariate analyses using various mixed-effects models showed that the effects of childhood SES could be largely explained by adult SES and that disadvantageous SES in adulthood further exacerbated declines in late-life cognitive functioning (β=-0.02; p<0.001), even controlling for aging, practice and other covariates. Possible factors that are associated with life-course socio-economic disadvantage and late-life cognitive decline included household income and perception of economic strain.

CONCLUSIONS

The results suggest a critical role for life-course socio-economic disadvantage in late-life cognitive decline and that this may be manifested via the inequitable distribution of socio-economic resources over the individual's life course.

The alcohol paradox: light-to-moderate alcohol consumption, cognitive function, and brain volume

BACKGROUND

Studies of older persons show consumption of light-to-moderate amounts of alcohol is positively associated with cognitive function and, separately, is negatively associated with total brain volume (TBV). This is paradoxical as generally, cognitive function is positively associated with TBV. We examined the relationships of TBV, global cognitive function (GCF), and alcohol consumption in a population-based cohort of 3,363 men and women (b. 1907-1935) participating in the Age Gene/Environment Susceptibility-Reykjavik Study (2002-2006) and who were free of dementia or mild cognitive impairment

METHODS

Drinking status (never, former, and current) and current amount of alcohol consumed were assessed by questionnaire. GCF is a composite score derived from a battery of cognitive tests. TBV, standardized to head size, is estimated quantitatively from brain magnetic resonance imaging.

RESULTS

Among women and not men, adjusting for demographic and cardiovascular risk factors, current drinkers had significantly higher GCF scores than abstainers and former drinkers (p < .0001); and GCF was associated with amount consumed. TBV was not associated with drinking status or amount consumed in men or women. GCF and TBV did significantly differ in their associations across alcohol categories (p interaction < .001). Within categories of alcohol intake, GCF and TBV were positively associated.

CONCLUSIONS

The difference in associations of alcohol intake to brain structure and function suggests there may be unmeasured factors that contribute to maintaining better GCF relative to TBV. However, at higher levels of reasonable alcohol consumption, there may be factors leading to reduced brain volume.

Public knowledge and beliefs about dementia risk reduction: a national survey of Australians

Background

With the dramatically increasing contribution of Alzheimer’s Disease and other forms of dementia to the global burden of disease, countries are being urged to address this as a public health priority. This study investigated whether Australian adults recognise this as an important health issue, and hold beliefs and knowledge that are consistent with recommendations concerning dementia risk reduction. This research was undertaken to guide national brain health awareness and education strategies.

Methods

A cross-sectional telephone survey was undertaken of 1,003 Australians aged 20–75 years. This measured the importance placed on dementia, beliefs and confidence related to risk reduction, knowledge of risk reduction methods, and the perceived age-relevance of these. In analysis the data were stratified by sex, age, educational attainment, household income, language preference and previous exposure to dementia. Multivariable logistic regression was undertaken to identify variables independently associated with beliefs and knowledge.

Results

People aged 60 years and over identified dementia as very important (17.2%) more often than those aged 40–59 years (5.1%) or 20–39 years (2.1%). While 41.5% of respondents believed the risk of dementia could be reduced, 26.9% were very confident that they could achieve this. Mental activity (57.1%) was identified as beneficial much more often than physical activity (31.3%), healthy eating (23.3%) and other cardiovascular health behaviours. Women, people of English-speaking origin, and those having contact with a person with dementia, showed better knowledge of several health behaviours.

Conclusions

Growing attention is being given to population risk reduction to combat the dramatic increase in the burden of disease due to dementia. In Australia many people do not yet hold beliefs and knowledge that support this, which highlights the need for concerted awareness raising that dementia is not an inevitable aspect of ageing, and for education about the role of vascular health in dementia risk reduction.

Gender differences in alcohol consumption among middle-aged and older adults in Australia, the United States and Korea

OBJECTIVES

To compare gender differences in alcohol use and the socioeconomic correlates of at-risk drinking among middle-aged and older adults in Australia, the United States (US) and South Korea.

METHOD

Data were drawn from large nationally representative surveys of people aged 45 years and older, collected in 2006.

RESULTS

Rates of any drinking and at-risk drinking (>14 US standard drinks/week) were higher for males than females in all countries and these gender differences were largest in Korea. Socioeconomic differentials for at-risk drinking varied by country and gender. In the US, at-risk drinking was associated with lower educational levels among men, but higher educational levels among women; in Korea, it was associated with being unpartnered, particularly for women; and in Australia, at-risk drinking was associated with higher income.

CONCLUSIONS

Gender-role expectations differ between countries and may influence both the levels at which older adults consume alcohol and the ways in which at-risk drinking is associated with socioeconomic factors.

IMPLICATIONS

Heavy alcohol use in middle-aged and older adults is a cause for concern. Health promotion strategies should target older age groups and consider the ways in which gender, marital status and education influence norms and opportunities for risky alcohol use.

Development of the motivation to change lifestyle and health behaviours for dementia risk reduction scale

Background and Aims

It is not yet understood how attitudes concerning dementia risk may affect motivation to change health behaviours and lifestyle. This study was designed to develop a reliable and valid theory-based measure to understand beliefs underpinning the lifestyle and health behavioural changes needed for dementia risk reduction.

Methods

617 participants aged ≥50 years completed a theory-based questionnaire, namely, the Motivation to Change Lifestyle and Health Behaviours for Dementia Risk Reduction (MCLHB-DRR) scale. The MCLHB-DRR consists of 53 items, reflecting seven subscales of the Health Belief Model.

Results

Confirmatory factor analysis was performed and revealed that a seven-factor solution with 27 items fitted the data (comparative fit index = 0.920, root-mean-square error of approximation = 0.047) better than the original 53 items. Internal reliability (α = 0.608-0.864) and test-retest reliability (α = 0.552-0.776) were moderate to high. Measurement of invariance across gender and age was also demonstrated.

Conclusions

These results propose that the MCLHB-DRR is a useful tool in assessing the beliefs and attitudes of males and females aged ≥50 years towards dementia risk reduction. This measure can be used in the development and evaluation of interventions aimed at dementia prevention.

Alcohol consumption and lifetime change in cognitive ability: a gene × environment interaction study

Studies of the effect of alcohol consumption on cognitive ability are often confounded. One approach to avoid confounding is the Mendelian randomization design. Here, we used such a design to test the hypothesis that a genetic score for alcohol processing capacity moderates the association between alcohol consumption and lifetime change in cognitive ability. Members of the Lothian Birth Cohort 1936 completed the same test of intelligence at age 11 and 70 years. They were assessed for recent alcohol consumption in later life and genotyped for a set of four single-nucleotide polymorphisms in three alcohol dehydrogenase genes. These variants were unrelated to late-life cognition or to socioeconomic status. We found a significant gene × alcohol consumption interaction on lifetime cognitive change (p = 0.007). Individuals with higher genetic ability to process alcohol showed relative improvements in cognitive ability with more consumption, whereas those with low processing capacity showed a negative relationship between cognitive change and alcohol consumption with more consumption. The effect of alcohol consumption on cognitive change may thus depend on genetic differences in the ability to metabolize alcohol.

Prevalence of cognitive impairment no dementia in a rural area of Northern China

OBJECTIVE

Few data are available on the prevalence of cognitive impairment no dementia (CIND) in rural China. The aim of this study was to estimate the prevalence of CIND in individuals aged 60 years and older in a large rural community, and to analyze the associated risk factors.

METHODS

A two-phase, door-to-door epidemiological study was used for residents aged 60 years and older in Ji County, a rural county near Tianjin in Northern China. In phase 1 of the study, the Mini-Mental State Examination and Clinical Dementia Rating were administered for screening purposes. In phase 2, the subjects who screened positive were further examined by neurologists. A total of 5,744 individuals underwent the home visit interview, where demographic variables and comorbidities were recorded; 5,550 individuals completed the two phases. CIND was diagnosed by the Aging, Demographics and Memory Study on CIND criteria. The odds ratio (OR) for each risk factor was calculated by logistic regression analysis.

RESULTS

The prevalence of CIND among those aged 60 years and older was 23.3%. The prevalence of CIND was lower among those with a higher level of education or social involvement. CIND was more prevalent in females, older individuals, those with a past history of stroke, and those living without a partner. Significant risk factors were found by multivariate analyses: past history of stroke (OR = 1.889; 95% CI: 1.437-2.483); being female (OR = 1.546; 95% CI: 1.305-1.832); and having no partner (divorced, widowed or single; OR = 1.250; 95% CI: 1.042-1.499). In turn, level of education (OR = 0.560; 95% CI: 0.460-0.681) and engagement in social activities (OR = 0.339; 95% CI: 0.258-0.404) were protective factors.

CONCLUSIONS

This is the first large-scale community-based epidemiological study assessing the prevalence of cognitive loss in the rural Chinese population. The total prevalence of CIND observed was 23.3%, which was higher than in other studies in Western and Asian countries. Living without a partner, female gender and previous stroke increased the risk of CIND, whereas a higher level of education and engagement in social activities reduced the risk of CIND.

Increased risk of dementia in patients with osteoporosis: a population-based retrospective cohort analysis

Osteoporosis is a common systemic skeletal disease that predominantly affects people older than 50 years and often co-occurs with dementia. The purpose of this study was to evaluate the risk of dementia in osteoporosis patients in Taiwan. Using data from Taiwan's National Health Insurance Research Database (NHIRD), we identified 23,941 patients with osteoporosis from 2000 to 2010 and 47,579 nonosteoporosis control patients, frequency-matched for age, sex, and index year, excluding patients with dementia at the baseline. We conducted univariate and multiple Cox proportional-hazards regression analyses to calculate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of the association between osteoporosis and risk of dementia. After adjustment for potential risk factors, the osteoporosis patients exhibited 1.46-fold and 1.39-fold higher risk of dementia (95 % CI = 1.37-1.56) and Alzheimer's disease (95 % CI = 0.95-2.02), respectively, compared with the matched nonosteoporosis patients. We observed increased risk of dementia in both men and women with osteoporosis. The osteoporosis patients receiving bisphosphonate treatment or estrogen supplementation were associated with significantly lower risk of dementia compared with the osteoporosis patients who did not receive any treatment. Overall, our results suggest higher risks of dementia in osteoporosis patients than in nonosteoporosis patients. Osteoporosis could thus be considered an early risk factor for dementia. Future large-scale double-blind randomized clinical trials are required to clarify the role of medication in osteoporosis-related dementia.

The mammalian circadian clock in the suprachiasmatic nucleus exhibits rapid tolerance to ethanol in vivo and in vitro

BACKGROUND

Ethanol (EtOH) triggers cellular adaptations that induce tolerance in many brain areas, including the suprachiasmatic nucleus (SCN), the site of the master circadian clock. EtOH inhibits light-induced phase shifts in the SCN in vivo and glutamate-induced phase shifts in vitro. The in vitro phase shifts develop acute tolerance to EtOH, occurring within minutes of initial exposure, while the in vivo phase shifts exhibit no evidence of chronic tolerance. An intermediate form, rapid tolerance, is not well studied but may predict subsequent chronic tolerance. Here, we investigated rapid tolerance in the SCN clock.

METHODS

Adult C57BL/6 mice were provided 15% EtOH or water for one 12-hour lights-off period. For in vitro experiments, SCN-containing brain slices were prepared in the morning and treated for 10 minutes with glutamate +/- EtOH the following night. Single-cell neuronal firing rates were recorded extracellularly during the subsequent day to determine SCN clock phase. For in vivo experiments, mice receiving EtOH 24 hours previously were exposed to a 30-minute light pulse immediately preceded by intraperitoneal saline or 2 g/kg EtOH injection. Mice were then placed in constant darkness and their phase-shifting responses measured.

RESULTS

In vitro, the SCN clock from EtOH-exposed mice exhibited rapid tolerance, with a 10-fold increase in EtOH needed to inhibit glutamate-induced phase shifts. Co-application of brain-derived neurotrophic factor prevented EtOH inhibition, consistent with experiments using EtOH-naïve mice. Rapid tolerance lasts 48 to 96 hours, depending on whether assessing in vitro phase advances or phase delays. Similarly, in vivo, prior EtOH consumption prevented EtOH's acute blockade of photic phase delays. Finally, immunoblot experiments showed no changes in SCN glutamate receptor subunit (NR2B) expression or phosphorylation in response to rapid tolerance induction.

CONCLUSIONS

The SCN circadian clock develops rapid tolerance to EtOH as assessed both in vivo and in vitro, and the tolerance lasts for several days. These data demonstrate the utility of the circadian system as a model for investigating cellular mechanisms through which EtOH acts in the brain.

A self-report risk index to predict occurrence of dementia in three independent cohorts of older adults: the ANU-ADRI

BACKGROUND AND AIMS

The Australian National University AD Risk Index (ANU-ADRI, http://anuadri.anu.edu.au) is a self-report risk index developed using an evidence-based medicine approach to measure risk of Alzheimer's disease (AD). We aimed to evaluate the extent to which the ANU-ADRI can predict the risk of AD in older adults and to compare the ANU-ADRI to the dementia risk index developed from the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study for middle-aged cohorts.

METHODS

This study included three validation cohorts, i.e., the Rush Memory and Aging Study (MAP) (n = 903, age ≥53 years), the Kungsholmen Project (KP) (n = 905, age ≥75 years), and the Cardiovascular Health Cognition Study (CVHS) (n = 2496, age ≥65 years) that were each followed for dementia. Baseline data were collected on exposure to the 15 risk factors included in the ANU-ADRI of which MAP had 10, KP had 8 and CVHS had 9. Risk scores and C-statistics were computed for individual participants for the ANU-ADRI and the CAIDE index.

RESULTS

For the ANU-ADRI using available data, the MAP study c-statistic was 0·637 (95% CI 0·596-0·678), for the KP study it was 0·740 (0·712-0·768) and for the CVHS it was 0·733 (0·691-0·776) for predicting AD. When a common set of risk and protective factors were used c-statistics were 0.689 (95% CI 0.650-0.727), 0.666 (0.628-0.704) and 0.734 (0.707-0.761) for MAP, KP and CVHS respectively. Results for CAIDE ranged from c-statistics of 0.488 (0.427-0.554) to 0.595 (0.565-0.625).

CONCLUSION

A composite risk score derived from the ANU-ADRI weights including 8-10 risk or protective factors is a valid, self-report tool to identify those at risk of AD and dementia. The accuracy can be further improved in studies including more risk factors and younger cohorts with long-term follow-up.

Alcohol consumption and cognitive decline in early old age

Objective:

To examine the association between alcohol consumption in midlife and subsequent cognitive decline.

Methods:

Data are from 5,054 men and 2,099 women from the Whitehall II cohort study with a mean age of 56 years (range 44–69 years) at first cognitive assessment. Alcohol consumption was assessed 3 times in the 10 years preceding the first cognitive assessment (1997–1999). Cognitive tests were repeated in 2002–2004 and 2007–2009. The cognitive test battery included 4 tests assessing memory and executive function; a global cognitive score summarized performances across these tests. Linear mixed models were used to assess the association between alcohol consumption and cognitive decline, expressed as z scores (mean = 0, SD = 1).

Results:

In men, there were no differences in cognitive decline among alcohol abstainers, quitters, and light or moderate alcohol drinkers (<20 g/d). However, alcohol consumption ≥36 g/d was associated with faster decline in all cognitive domains compared with consumption between 0.1 and 19.9 g/d: mean difference (95% confidence interval) in 10-year decline in the global cognitive score = −0.10 (−0.16, −0.04), executive function = −0.06 (−0.12, 0.00), and memory = −0.16 (−0.26, −0.05). In women, compared with those drinking 0.1 to 9.9 g/d of alcohol, 10-year abstainers showed faster decline in the global cognitive score (−0.21 [−0.37, −0.04]) and executive function (−0.17 [−0.32, −0.01]).

Conclusions:

Excessive alcohol consumption in men (≥36 g/d) was associated with faster cognitive decline compared with light to moderate alcohol consumption.

Persistent long-standing illness and non-drinking over time, implications for the use of lifetime abstainers as a control group

BACKGROUND

Non-drinkers are shown to have worse health than moderate drinkers in later life. We examine the preceding health status of non-drinkers in early adulthood, and secondly whether persistent poor health is associated with persistent non-drinking.

METHODS

Using two prospective British birth cohort studies established in 1958 (National Child Development Study (NCDS)) and in 1970 (British Cohort Study (BCS)), participants who reported 'never' or 'never had an alcoholic drink' to drinking status questions in successive waves from 23 to 26 years in the NCDS/BCS were derived as 'lifetime abstainers'. Logistic regression on the odds of being a lifetime abstainer was carried out on changes in limiting long-standing illness (LLSI) in the NCDS and long-standing illness (LSI) in the BCS, adjusting for sex, education, poor psychosocial health, marital and parental status.

RESULTS

Participants with an LLSI in consecutive waves since 23 years had 4.50 times the odds of someone who did not have an LLSI of being a lifetime abstainer at 33 years (95% CI 1.99 to 10.18) and 7.02 times the odds at 42 years (2.39 to 20.66) after adjusting for all factors. Similarly, in the BCS, having an LSI in consecutive waves resulted in higher odds of being a lifetime abstainer at 30 years (OR 2.80, 1.88 to 4.18) and 34 years (OR 3.33, 2.01 to 5.53).

CONCLUSIONS

Persistent LSI was associated with remaining a non-drinker across adulthood. Studies comparing the health outcomes of moderate drinkers to lifetime abstainers that do not account for pre-existing poor health may overestimate the better health outcomes from moderate alcohol consumption.

Alcohol-a universal preventive agent? A critical analysis

BACKGROUND

In observational studies, moderate drinking is associated with a reduced risk of more than twenty different diseases and health problems. However, it would be premature to conclude that there is a causal relationship.

METHOD

This paper critically reviews the evidence for such associations.

FINDINGS

It was found that reasons for questioning the causal association of moderate drinking and a reduced health risk are: the lack of dose-response relationships; the characteristics and lifestyles of today's abstainers and moderate drinkers; the lack of plausible biological mechanisms; the problems in the classification of drinking groups, and; the general limitations of observational studies.

CONCLUSIONS

The evidence for the harmful effects of alcohol is undoubtedly stronger than the evidence for beneficial effects.

Gender differences in the association of smoking and drinking with the development of cognitive impairment

Modifiable lifestyle-related factors such as smoking and alcohol drinking are associated with cognitive impairment in the elderly population but the relationships have shown various results. To evaluate the relationship of alcohol drinking and smoking in the early 60 s with the risk of developing incident cognitive impairment. In 1999, we evaluated cognitive function, smoking, and drinking status in 3,174 inhabitants aged 60–64 years in a rural area of Korea, with a follow-up assessment of cognitive function 7 years later. A total of 1,810 individuals who did not show cognitive impairment at baseline were included. A stratified analysis was applied to evaluate how smoking and alcohol drinking affected the risk of developing cognitive impairment based on gender. Current smokers showed a higher risk for developing cognitive impairment than did never smokers (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.09–2.15). The OR for female current smokers compared with never smokers was 1.62 (95% CI, 1.05–2.52), and smokers with higher pack-years were more likely to develop cognitive impairment than never smokers, showing a dose–response relationship (P for trend = 0.004). Frequent alcohol consumption increased the risk of developing cognitive impairment (OR, 1.68; 95% CI, 1.01–2.78), and a dose–response relationship was observed among male subjects (P for trend = 0.044). Infrequent drinking in females decreased the odds of developing cognitive impairment (OR, 0.67; 95% CI, 0.42–1.00), whereas frequent drinking tended to increase the odds, although this trend was not significant, suggesting a U-shaped relationship. Although the sample was small for some analyses, especially in female, our data suggest that smoking and drinking in the early 60 s are associated with a risk of developing cognitive impairment, and this relationship is characterized by gender differences.

The relationship between midlife and late life alcohol consumption, APOE e4 and the decline in learning and memory among older adults

AIMS

The aim of the study was to determine whether the trajectory of learning and memory is modified according to an interaction between midlife or late life alcohol consumption status and the presence of one or more APOE e4 alleles.

METHODS

This was a secondary analysis of cognitive, genetic and alcohol consumption data collected from members of the Framingham Heart Study Offspring Cohort.

RESULTS

Light and moderate alcohol consumption during late life was associated with greater decline in learning and memory among APOE e4 carriers, whereas light and moderate alcohol consumption was associated with an increase in learning and memory among non-APOE e4 carriers. There was not a significant interaction between midlife alcohol consumption status and APOE e4 on the trajectory of learning and memory.

CONCLUSION

Light to moderate alcohol consumption during late life may protect against a decline in learning and memory for non-APOE e4 allele carriers, but not for older adults who carry one or more APOE e4 alleles.

Consumption of alcoholic beverages and cognitive decline at middle age: the Doetinchem Cohort Study

Accelerated cognitive decline increases the risk of dementia. Slowing down the rate of cognitive decline leads to the preservation of cognitive functioning in the elderly, who can live independently for a longer time. Alcohol consumption may influence the rate of cognitive decline. The aim of the present study was to evaluate the associations between the total consumption of alcoholic beverages and different types of alcoholic beverages and cognitive decline at middle age. In 2613 men and women of the Doetinchem Cohort Study, aged 43–70 years at baseline (1995–2002), cognitive function (global cognitive function and the domains memory, speed and flexibility) was assessed twice, with a 5-year time interval. In linear regression analyses, the consumption of different types of alcoholic beverages was analysed in relation to cognitive decline, adjusting for confounders. We observed that, in women, the total consumption of alcoholic beverages was inversely associated with the decline in global cognitive function over a 5-year period (P for trend = 0·02), while no association was observed in men. Regarding the consumption of different types of alcoholic beverages in men and women together, red wine consumption was inversely associated with the decline in global cognitive function (P for trend < 0·01) as well as memory (P for trend < 0·01) and flexibility (P for trend = 0·03). Smallest declines were observed at a consumption of about 1·5 glasses of red wine per d. No other types of alcoholic beverages were associated with cognitive decline. In conclusion, only (moderate) red wine consumption was consistently associated with less strong cognitive decline. Therefore, it is most likely that non-alcoholic substances in red wine are responsible for any cognition-preserving effects.

The impact of alcohol on Alzheimer's disease: a systematic review

Currently, there is discrepancy regarding alcohol's impact on Alzheimer's disease (AD). Consequently, the purpose of this systematic review was to determine whether alcohol serves as a protective agent against the development of AD, as well as whether protective effects are influenced by quantity and/or frequency of drinking. Adapted versions of the Matrix Method and PRISMA guidelines were used in order to identify, organize, and synthesize relevant research. Overall, there is no consensus regarding alcohol's impact on AD. Specifically, seven articles suggested drinking alcohol decreases the risk of AD, three studies found drinking led to an increased risk of AD, and yet another nine reported alcohol had no impact on AD. Validity and consistency of both alcohol and AD measures across studies represents a severe limitation. Prior to the development of standards and/or clinical recommendations, more investigations into the association between alcohol and AD are necessary. Considering the current evidence base, alcohol should not be used as a means to decrease risk of developing AD.

Adaptation and sensitization to proteotoxic stress

Although severe stress can elicit toxicity, mild stress often elicits adaptations. Here we review the literature on stress-induced adaptations versus stress sensitization in models of neurodegenerative diseases. We also describe our recent findings that chronic proteotoxic stress can elicit adaptations if the dose is low but that high-dose proteotoxic stress sensitizes cells to subsequent challenges. In these experiments, long-term, low-dose proteasome inhibition elicited protection in a superoxide dismutase-dependent manner. In contrast, acute, high-dose proteotoxic stress sensitized cells to subsequent proteotoxic challenges by eliciting catastrophic loss of glutathione. However, even in the latter model of synergistic toxicity, several defensive proteins were upregulated by severe proteotoxicity. This led us to wonder whether high-dose proteotoxic stress can elicit protection against subsequent challenges in astrocytes, a cell type well known for their resilience. In support of this new hypothesis, we found that the astrocytes that survived severe proteotoxicity became harder to kill. The adaptive mechanism was glutathione dependent. If these findings can be generalized to the human brain, similar endogenous adaptations may help explain why neurodegenerative diseases are so delayed in appearance and so slow to progress. In contrast, sensitization to severe stress may explain why defenses eventually collapse in vulnerable neurons.

Development of a new method for assessing global risk of Alzheimer's disease for use in population health approaches to prevention

Alzheimer's disease (AD) affects approximately 35 million people worldwide. Increasing evidence suggests that many risk factors for AD are modifiable. AD pathology develops over decades. Hence risk reduction interventions require very long follow-ups to show effects on AD incidence. Focussing on AD risk, instead of diagnosis, provides a more realistic target for prevention strategies. We developed a novel methodology that yields a global approach to risk assessment for AD for use in population-based settings and interventions. The methodology was used to develop a risk assessment tool that can be updated as more evidence becomes available. First, a systematic search strategy identified risk and protective factors for AD. Eleven risk factors and four protective factors for AD were identified for which odds ratios were published or could be calculated (age, sex, education, body mass index, diabetes, depression, serum cholesterol, traumatic brain injury, smoking, alcohol intake, social engagement, physical activity, cognitive activity, fish intake, and pesticide exposure). An algorithm was developed to combine the odds ratios into an AD risk score. The approach allows for interactions among risk factors which provides for their varying impact over the life-course as current evidence suggests midlife is a critical period for some risk factors. Finally, a questionnaire was developed to assess the risk and protective factors by self-report. Compared with developing risk indices on single cohort studies, this approach allows for more risk factors to be included, greater generalizeability of results, and incorporation of interactions based on findings from different stages of the lifecourse.

Combined impact of smoking and heavy alcohol use on cognitive decline in early old age: Whitehall II prospective cohort study

BACKGROUND

Identifying modifiable risk factors for cognitive decline may inform prevention of dementia.

AIMS

To examine the combined impact of cigarette smoking and heavy alcohol consumption on cognitive decline from midlife.

METHOD

Prospective cohort study (Whitehall II cohort) with three clinical examinations in 1997/99, 2002/04 and 2007/09. Participants were 6473 adults (72% men), mean age 55.76 years (s.d. = 6.02) in 1997/99. Four cognitive tests, assessed three times over 10 years, combined into a global z-score (mean 0, s.d. = 1).

RESULTS

Age-related decline in the global cognitive score was faster in individuals who were smoking heavy drinkers than in non-smoking moderate alcohol drinkers (reference group). The interaction term (P = 0.04) suggested that the combined effects of smoking and alcohol consumption were greater than their individual effects. Adjusting for age, gender, education and chronic diseases, 10-year decline in global cognition was -0.42 z-scores (95% CI -0.45 to -0.39) for the reference group. In individuals who were heavy alcohol drinkers who also smoked the decline was -0.57 z-scores (95% CI -0.67 to -0.48); 36% faster than the reference group.

CONCLUSIONS

Individuals who were smokers who drank alcohol heavily had a 36% faster cognitive decline, equivalent to an age-effect of 2 extra years over 10-year follow-up, compared with individuals who were non-smoking moderate drinkers.

Risk factors for dementia with Lewy bodies: a case-control study

OBJECTIVE

To determine the risk factors associated with dementia with Lewy bodies (DLB).

METHODS

We identified 147 subjects with DLB and sampled 2 sex- and age-matched cognitively normal control subjects for each case. We also identified an unmatched comparison group of 236 subjects with Alzheimer disease (AD). We evaluated 19 candidate risk factors in the study cohort.

RESULTS

Compared with controls, subjects with DLB were more likely to have a history of anxiety (odds ratio; 95% confidence interval) (7.4; 3.5-16; p < 0.0001), depression (6.0; 3.7-9.5; p < 0.0001), stroke (2.8; 1.3-6.3; p = 0.01), a family history of Parkinson disease (PD) (4.6; 2.5-8.6; p < 0.0001), and carry APOE ε4 alleles (2.2; 1.5-3.3; p < 0.0001), but less likely to have had cancer (0.44; 0.27-0.70; p = 0.0006) or use caffeine (0.29; 0.14-0.57; p < 0.0001) with a similar trend for alcohol (0.65; 0.42-1.0; p = 0.0501). Compared with subjects with AD, subjects with DLB were younger (72.5 vs 74.9 years, p = 0.021) and more likely to be male (odds ratio; 95% confidence interval) (5.3; 3.3-8.5; p < 0.0001), have a history of depression (4.3; 2.4-7.5; p < 0.0001), be more educated (2.5; 1.1-5.6; p = 0.031), have a positive family history of PD (5.0; 2.4-10; p < 0.0001), have no APOE ε4 alleles (0.61; 0.40-0.93; p = 0.02), and to have had an oophorectomy before age 45 years (7.6; 1.5-39; p = 0.015).

CONCLUSION

DLB risk factors are an amalgam of those for AD and PD. Smoking and education, which have opposing risk effects on AD and PD, are not risk factors for DLB; however, depression and low caffeine intake, both risk factors for AD and PD, increase risk of DLB more strongly than in either.

Nutrition and the risk of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for the major cause of dementia, and the increasing worldwide prevalence of AD is a major public health concern. Increasing epidemiological studies suggest that diet and nutrition might be important modifiable risk factors for AD. Dietary supplementation of antioxidants, B vitamins, polyphenols, and polyunsaturated fatty acids are beneficial to AD, and consumptions of fish, fruits, vegetables, coffee, and light-to-moderate alcohol reduce the risk of AD. However, many of the results from randomized controlled trials are contradictory to that of epidemiological studies. Dietary patterns summarizing an overall diet are gaining momentum in recent years. Adherence to a healthy diet, the Japanese diet, and the Mediterranean diet is associated with a lower risk of AD. This paper will focus on the evidence linking many nutrients, foods, and dietary patterns to AD.

Alcohol Consumption, Types of Alcohol, and Parkinson's Disease

Background

The epidemiologic evidence on alcohol consumption and Parkinson’s disease (PD) is equivocal. We prospectively examined total alcohol consumption and consumption of specific types of alcoholic beverage in relation to future risk of PD.

Methods

The study comprised 306,895 participants (180,235 male and 126,660 female) ages 50–71 years in 1995–1996 from the NIH-AARP Diet and Health Study. Consumption of alcoholic beverages in the past 12 months was assessed in 1995–1996. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were obtained from logistic regression models.

Results

A total of 1,113 PD cases diagnosed between 2000 and 2006 were included in the analysis. Total alcohol consumption was not associated with PD. However, the association differed by types of alcoholic beverages. Compared with non-beer drinkers, the multivariate ORs for beer drinkers were 0.79 (95% CI: 0.68, 0.92) for <1 drink/day, 0.73 (95% CI: 0.50, 1.07) for 1–1.99 drinks/day, and 0.86 (95% CI: 0.60, 1.21) for ≥2 drinks/day. For liquor consumption, a monotonic increase in PD risk was suggested: ORs (95% CI) were 1.06 (0.91, 1.23), 1.22 (0.94, 1.58), and 1.35 (1.02, 1.80) for <1, 1–1.99, and ≥2 drinks/day, respectively (P for trend <0.03). Additional analyses among exclusive drinkers of one specific type of alcoholic beverage supported the robustness of these findings. The results for wine consumption were less clear, although a borderline lower PD risk was observed when comparing wine drinkers of 1–1.99 drinks/day with none drinkers (OR = 0.74, 95% CI: 0.53, 1.02).

Conclusions

Our results suggest that beer and liquor consumption may have opposite associations with PD: low to moderate beer consumption with lower PD risk and greater liquor consumption with higher risk. These findings and potential underlying mechanisms warrant further investigations.

Moderate alcohol use and health: a consensus document

AIMS

The aim of this consensus paper is to review the available evidence on the association between moderate alcohol use, health and disease and to provide a working document to the scientific and health professional communities.

DATA SYNTHESIS

In healthy adults and in the elderly, spontaneous consumption of alcoholic beverages within 30 g ethanol/d for men and 15 g/d for women is to be considered acceptable and do not deserve intervention by the primary care physician or the health professional in charge. Patients with increased risk for specific diseases, for example, women with familiar history of breast cancer, or subjects with familiar history of early cardiovascular disease, or cardiovascular patients should discuss with their physician their drinking habits. No abstainer should be advised to drink for health reasons. Alcohol use must be discouraged in specific physiological or personal situations or in selected age classes (children and adolescents, pregnant and lactating women and recovering alcoholics). Moreover, the possible interactions between alcohol and acute or chronic drug use must be discussed with the primary care physician.

CONCLUSIONS

The choice to consume alcohol should be based on individual considerations, taking into account the influence on health and diet, the risk of alcoholism and abuse, the effect on behaviour and other factors that may vary with age and lifestyle. Moderation in drinking and development of an associated lifestyle culture should be fostered.

Nonpharmacologic treatment and prevention strategies for dementia

PURPOSE OF REVIEW

Epidemiologic studies can provide critical evidence to inform the timing and duration of nonpharmacologic interventions. Although more studies are needed to further determine long-term efficacy, the evidence supporting modifiable risk factors for prevention is compelling, and prevention strategies that incorporate multidomain nonpharmacologic factors may have the most impact.

RECENT FINDINGS

Epidemiologic studies have identified a number of promising nonpharmacologic factors that have the potential to lower the risk of developing dementia.

SUMMARY

Potential modifiable strategies for dementia prevention include cardiovascular risk factors; lifestyle risk factors such as physical, cognitive, and social activity as well as nutrition, smoking, and alcohol use; and sleep quality. Results of randomized controlled trials for the treatment of cardiovascular risk factors have not been consistent, while interventions that increase physical, cognitive, and social activity have demonstrated protective effects for dementia risk. Trials of single-nutrient dietary supplementation have also been conflicting, but focus on multinutrient supplementation shows promise. Observational data also indicate that sleep quality may be a modifiable risk factor for dementia prevention.

Alcohol and smoking consumption behaviours in older Australian adults: prevalence, period and socio-demographic differentials in the DYNOPTA sample

PURPOSE

Alcohol consumption and tobacco use are key risk factors for chronic disease and health burden across the adult lifespan. We estimate the prevalence of alcohol consumption and smoking by age and time period in adults from mid to old age.

METHODS

Participants (n = 50,652) were drawn from the Dynamic Analyses to Optimise Ageing (DYNOPTA) project and were compared with Australian National Health Survey data. Alcohol and smoking consumption DYNOPTA data were weighted to the estimated resident population of the sampling frame for each contributing study according to age and sex distributions within major statistical regions.

RESULTS

Comparisons in the rates of smoking and alcohol consumption between DYNOPTA and other national surveys were comparable. Males were more likely to be (RRR = 2.12) or have been smokers (RRR = 2.97), whilst females were more likely to be non-drinkers (RRR = 2.52). Period effects were also identified; higher prevalence rates in consumption of alcohol (RRR = 3.21) and smoking (RRR = 1.67) for those contributing studies from the early 1990's, in comparison with those studies from the latter half of the decade, were reported.

CONCLUSIONS

Over a decade, prevalence rates for high-risk consumption of alcohol and current smoking behaviour declined and suggest the possible impact of government health policy, with targeted-health policies, that included bans on public smoking, and a toughening of legislation against alcohol-related crime.

A 12-week multidomain intervention versus active control to reduce risk of Alzheimer's disease: study protocol for a randomized controlled trial

BACKGROUND

Disappointing results from clinical trials of disease-modifying interventions for Alzheimer's dementia (AD), along with reliable identification of modifiable risk factors in mid life from epidemiological studies, have contributed to calls to invest in risk-reduction interventions. It is also well known that AD-related pathological processes begin more than a decade before the development of clinical signs. These observations suggest that lifestyle interventions might be most effective when targeting non-symptomatic adults at risk of AD. To date, however, the few dementia risk-reduction programs available have targeted individual risk factors and/or were restricted to clinical settings. The current study describes the development of an evidence-based, theoretically-driven multidomain intervention to reduce AD risk in adults at risk.

METHOD

The design of Body Brain Life (BBL) is a randomized controlled trial (RCT) to evaluate a 12-week online AD risk-reduction intervention. Eligible participants with several modifiable risk factors on the Australian National University (ANU) AD Risk Index (ANU-ADRI) are randomly allocated to an online only group, an online and face-to-face group, or an active control group. We aim to recruit 180 participants, to undergo a comprehensive cognitive and physical assessment at baseline, post-intervention, and 6-month follow-up assessment. The intervention comprises seven online modules (dementia literacy, risk factor education, engagement in physical, social, and cognitive lifestyles, nutrition, and health monitoring) designed using contemporary models of health behavior change.

DISCUSSION

The BBL program is a novel online intervention to reduce the risk of AD in middle-aged adults at risk. The trial is currently under way. It is hypothesized that participants in the intervention arms will make lifestyle changes in several domains, and that this will lead to a reduction in their AD risk profile. We also expect to show that health behavior change is underpinned by changes in psychological determinants of behavior. If successful, the findings will contribute to the development of further dementia risk reduction interventions, and thus contribute to the urgent need to lower dementia risk factors in the population to alter future projections of disease prevalence. Longer follow-up of BBL participants and replications using large samples are required to examine whether reduction in AD risk factors will be associated with reduced prevalence.

TRIAL REGISTRATION

Reg. no. ACTRN12612000147886.

Nutraceutical strategies for ameliorating the toxic effects of alcohol

Rodent studies reveal that oxidative stress, much of it generated via induction/activation of NADPH oxidase, is a key mediator of a number of the pathogenic effects of chronic ethanol overconsumption. The highly reactive ethanol metabolite acetaldehyde is a key driver of this oxidative stress, and doubtless works in other ways to promote alcohol-induced pathology. Effective antioxidant measure may therefore be useful for mitigating the adverse health consequences of alcohol consumption; spirulina may have particular utility in this regard, as its chief phycochemical phycocyanobilin has recently been shown to function as an inhibitor of certain NADPH oxidase complexes, mimicking the physiological role of its chemical relatives biliverdin/bilirubin in this respect. Moreover, certain nutraceuticals, including taurine, pantethine, and lipoic acid, may have the potential to boost the activity of the mitochondrial isoform of aldehyde dehydrogenase, ALDH-2, accelerating conversion of acetaldehyde to acetate (which arguably has protective health effects). Little noticed clinical studies conducted nearly three decades ago reported that pre-ingestion of either taurine or pantethine could blunt the rise in blood acetaldehyde following ethanol consumption. Other evidence suggests that lipoic acid may function within mitochondria to maintain aldehyde dehydrogenase in a reduced active conformation; the impact of this agent on ethanol metabolism has however received little or no study. Studies evaluating the impact of nutracetical strategies on prevention of hangovers - which likely are mediated by acetaldehyde - may represent a quick, low-cost way to identify nutraceutical regimens that merit further attention for their potential impact on alcohol-induced pathology. Measures which boost or preserve ALDH-2 activity may also have important antioxidant potential, as this enzyme functions physiologically to protect cells from toxic aldehydes generated by oxidant stress.

Predicting 10-year alcohol use trajectories among men age 50 years and older

OBJECTIVE

To describe common 10-year drinking trajectories followed by men age 50 years or older and identify risk factors for those trajectories.

DESIGN

Longitudinal data were used to derive a semiparametric group-based model.

PARTICIPANTS

Men from the Health and Retirement Study age 50-65 years in 1998 who completed three or more of the six interviews conducted from 1998 to 2008, including our 1998 baseline interview.

MEASUREMENTS

Biannual data on number of drinks per drinking day were used to derive drinking trajectories. Risk factors included baseline age, race, ethnicity, education, marital status, retirement, smoking, binge drinking, vigorous exercise, body mass index, depression, pain, self-reported health, and chronic disease.

RESULTS

The best-fitting model included consistent infrequent drinkers and nondrinkers (40.6% of cohort), increasing drinkers (5.5%), decreasing drinkers (7.6%), consistent at-risk drinkers (15.6%), and consistent moderate drinkers (30.7%). Adjusted logistic regression models comparing men with similar 1998 drinking levels who subsequently followed different trajectories identified significant risks associated with age, education, smoking, binge drinking, depression, pain, and self-reported health. To illustrate, odds ratios (ORs) and 95% confidence intervals (95% CIs) suggest that baseline infrequent drinkers were less likely to follow an increasing drinkers trajectory if they were older (OR: 0.57, 95% CI: 0.38-0.82) and smoked cigarettes (OR: 0.47, 95% CI: 0.30-0.74). Baseline drinkers were less likely to follow a decreasing trajectory if they reported more than 12 years of education (OR: 0.58, 95% CI: 0.42-0.82) and thought that their health was excellent or very good (OR: 0.54, 95% CI: 0.39-0.76).

CONCLUSION

Only 30.7% of older men in this cohort were moderate drinkers throughout the follow-up. Many older men may benefit from brief counseling on the risks and benefits of drinking.

Alcohol consumption in mild cognitive impairment and dementia: harmful or neuroprotective?

OBJECTIVE

In several longitudinal studies, light-to-moderate drinking of alcoholic beverages has been proposed as being protective against the development of age-related changes in cognitive function, predementia syndromes, and cognitive decline of degenerative (Alzheimer's disease, AD) or vascular origin (vascular dementia). However, contrasting findings also exist.

METHOD

The English literature published in this area before September 2011 was evaluated, and information relating to the various factors that may impact upon the relationship between alcohol consumption and dementia or predementia syndromes is presented in the succeeding texts.

RESULTS

Light-to-moderate alcohol consumption may be associated with a reduced risk of incident overall dementia and AD; however, protective benefits afforded to vascular dementia, cognitive decline, and predementia syndromes are less clear. The equivocal findings may relate to many of the studies being limited to cross-sectional designs, restrictions by age or gender, or incomplete ascertainment. Different outcomes, beverages, drinking patterns, and study follow-up periods or possible interactions with other lifestyle-related (e.g., smoking) or genetic factors (e.g., apolipoprotein E gene variation) may all contribute to the variability of findings.

CONCLUSION

Protective effects of moderate alcohol consumption against cognitive decline are suggested to be more likely in the absence of the AD-associated apolipoprotein E ε4 allele and where wine is the beverage. At present, there is no indication that light-to-moderate alcohol drinking would be harmful to cognition and dementia, and attempts to define what might be deemed beneficial levels of alcohol intake in terms of cognitive performance would be highly problematic and contentious.

Epidemiology of dementias and Alzheimer's disease

BACKGROUND AND AIMS

Global population aging has been one of the defining processes of the twentieth century, with profound economic, political and social consequences. It is driving the current epidemic of dementia, both in terms of its extent and global distribution. The aim of the study was to summarize recent findings relevant to the epidemiological knowledge of dementia and Alzheimer's disease (AD).

METHODS

A narrative mini-review of the literature relevant to the epidemiology of dementia and AD is presented, summarizing important findings and analyzing their implications.

RESULTS

It was estimated that in 2010 there were 36.5 million people living with dementia, with 7.7 million new cases yearly and a new case of dementia every 4 sec. The number of persons living with dementia will nearly double every 20 years. Most of these persons will be living in low- and middle-income countries (LMIC).

CONCLUSIONS

There are a substantial number of people with dementia worldwide and these numbers will continue to increase mainly in LMIC, producing a wide range of impacts. It is important to make dementia a national public health and social care priority worldwide. Recent reviews and meta-analyses have failed to clearly identify a singular causal or preventive pathway for AD that seems to be a multicausal, heterogeneous and age-related condition.

Alcohol consumption and premotor corpus callosum in older adults

Heavy alcohol consumption is toxic to the brain, especially to the frontal white matter (WM), but whether lesser amounts of alcohol negatively impact the brain WM is unclear. In this study, we examined the relationship between self-reported alcohol consumption and regional WM and grey matter (GM) volume in fifty-six men and thirty-seven women (70+- 7years) cognitively intact participants of the Baltimore Longitudinal Study of Aging (BLSA) with no history of alcohol abuse. We used regional analysis of volumes examined in normalized space (RAVENS) maps methodology for WM and GM segmentation and normalization followed by voxel based morphometry (VBM) implemented in SPM8 to examine the cross-sectional association between alcohol consumption and regional WM (and, separately, GM) volume controlling for age, sex, smoking, blood pressure and dietary thiamine intake. WM VBM revealed that in men, but not in women, higher alcohol consumption was associated with lower volume in premotor frontal corpus callosum. This finding suggests that even moderate amounts of alcohol may be detrimental to corpus callosum and white matter integrity.

Patients with chronic kidney disease are at an elevated risk of dementia: a population-based cohort study in Taiwan

Background

Chronic kidney disease (CKD) is more prevalent in Taiwan than in most countries. This population-based cohort study evaluated the dementia risk associated with CKD.

Methods

Using claims data of 1,000,000 insured residents covered in the universal health insurance of Taiwan, we selected 37049 adults with CKD newly diagnosed from 2000–2006 as the CKD cohort. We also randomly selected 74098 persons free from CKD and other kidney diseases, frequency matched with age, sex and the date of CKD diagnosed. Incidence and hazard ratios (HRs) of dementia were evaluated by the end of 2009.

Results

Subjects in the CKD cohort were more prevalent with comorbidities than those in the non-CKD cohort (p <0.0001). The dementia incidence was higher in the CKD cohort than in the non-CKD cohort (9.30 vs. 5.55 per 1,000 person-years), with an overall HR of 1.41 (95% confidence interval (CI), 1.32-1.50), controlling for sex, age, comorbidities and medicaitions. The risk was similar in men and women but increased sharply with age to an HR of 133 (95% CI, 68.9-256) for the elderly. However, the age-specific CKD cohort to non-CKD cohort incidence rate ratio decreased with age, with the highest ratio of 16.0 (95% CI, 2.00-128) in the youngest group. Among comorbidities and medications, alcoholism and taking benzodiazepines were also associated with dementia with elevated adjusted HRs of 3.05 (95% CI 2.17-4.28) and 1.23 (95% CI 1.14-1.32), respectively.

Conclusions

Patients with CKD could have an elevated dementia risk. CKD patients with comorbidity deserve attention to prevent dementia.

Gender differences in the link between excessive drinking and domain-specific cognitive functioning among older adults

OBJECTIVE

This study investigated gender differences in the relationship between excessive drinking and two cognitive domains among older adults.

METHOD

Using data from the Health and Retirement Study, 3,888 females and 2,350 males were analyzed separately. Multivariate regression was used to analyze the association between excessive drinking and fluid intelligence score. Logistic regression was conducted to examine the relationship between excessive drinking and crystallized intelligence.

RESULTS

Multivariate analysis showed that compared to non-excessive drinking, excessive drinking did not have a significant impact on fluid intelligence for either women or men, but it had a significantly negative association with a high crystallized intelligence score for women.

DISCUSSION

Findings suggest that the relationship between excessive drinking and cognition varies with gender when crystallized intelligence is measured. Clinicians and service providers should consider gender differences when developing strategies for the prevention and treatment of alcohol-related cognitive decline among older adults.