Dementia

Cognitive function is an intellectual process by which we become aware of, perceive, or comprehend ideas. It involves all aspects of perception, thinking, reasoning, and remembering.Infanthood and early childhood are the periods in life where most individuals are able to absorb and use new information the best. The capacity to learn normally slows down with age, but the overall cognitive function should not decline on a large scale in healthy individuals. Cognitive dysfunction is defined as an unusually poor mental function associated with confusion, forgetfulness and difficulty to concentrate. Factors such as ageing and disease may affect cognitive function over time. Growing evidence supports the role of vascular disease and vascular risk factors in cognitive decline, Alzheimer's Disease and dementia.

 

Dementia is a form of cognitive impairment where an individual loses the ability to think, remember and reason due to physical changes in the brain. Alzheimer’s disease (AD) is a form of dementia. AD and other types of dementia are most common in the elderly, and are associated with huge health costs. With a rapidly aging population throughout the world, factors that affect the risk of cognitive decline and dementia are of great importance. Recently, insulin resistance and hyperinsulineamia, the precursors of type 2 diabetes have been linked to an increased risk of cognitive impairment.

 

The moderate consumption of alcoholic beverages has consistently been associated with a decreased cardiovascular risk, so it may be hypothesized that this cardiovascular protection could also decrease vascular dementia and cognitive decline because alcohol might improve blood flow in the brain and prevent the deposit of plaques . Even though chronic abuse of alcoholic beverages can cause progressive neurodegenerative disease, many studies have suggested that a moderate intake is associated with a lower risk of dementia or cognitive impairment.

 

At present, there are no proven pharmaceutical drugs and therapies to prevent or treat cognitive decline or dementia, although a number of prospective epidemiologic studies have shown a lower risk of such conditions among light to moderate drinkers of wine and other alcoholic beverages in comparison with non-drinkers.  When the effect of different alcoholic beverages was examined, the results indicated that only moderate wine consumption was independently associated with better performance on all cognitive tests in both men and women. 

In the literature, there are many mechanisms proposed to explain these results. Wine may affect the risk factors for ischemic processes and stroke positively. It has been suggested that the antioxidant properties of the phenolic compounds in wine may help to prevent the oxidative damage implicated in dementia. Oxidative stress is thought to be involved in Alzheimer’s Disease by the formation of amyloid-ß protein and DNA damage in neurons in the brain. Resveratrol with its antioxidant and anti-inflammatory effects may also play a role.  In addition, alcohol increases the levels of HDL cholesterol and fibrinolytic factors resulting in a lower platelet aggregation. Furthermore, moderate consumption of wine and other alcoholic beverages enhances insulin sensitivity and consequently, may improve the memory function in subjects with early AD or mild cognitive impairment.

 

It is also possible that the beneficial effects of moderate drinking noted in studies might just be a marker for an overall healthy lifestyle. The Mediterranean diet with whole grains, fresh fruit and vegetables, olive oil and moderate red wine also reduces the risk of dementia, as does exercise, social engagement, mental activities and an optimistic outlook on life.

 

Experimental animal studies indicated that the phenolic compounds in wine were able to prevent the formation of plaques that are associated with the development of AD and other forms of dementia.

 

The above summary provides an overview of the topic, for more details and specific questions, please refer to the articles in the database.

 

 

 

 

The authors evaluated the association of low-to-moderate alcohol consumption with risk of cognitive decline in a census-based cohort study of men and women aged >/=55 years conducted in Zaragoza, Spain (1994-1999). Participants free of dementia at baseline (N = 3,888) were examined after 2.5 and 4.5 years of follow-up. Information on alcohol intake was collected with the EURODEM Risk Factors Questionnaire and the History and Aetiology Schedule. The study endpoint was severe cognitive decline, defined as loss of >/=1 point/year on the Mini-Mental State Examination or a diagnosis of incident dementia (Diagnostic and Statistical Manual of Mental Disorders: DSM-IV, Text Revision criteria). Compared with those for abstainers, the multivariate-adjusted odds ratios for severe cognitive decline for male drinkers of
The relationships between alcohol consumption and dementia and cognitive decline were investigated in a systematic review including meta-analyses of 15 prospective studies. Follow-ups ranged from 2 to 8 years. Meta-analyses were conducted on samples including 14,646 participants evaluated for Alzheimer disease (AD), 10,225 participants evaluated for vascular dementia (VaD), and 11,875 followed for any type of dementia (Any dementia). The pooled relative risks (RRs) of AD, VaD, and Any dementia for light to moderate drinkers compared with nondrinkers were 0.72 (95% CI = 0.61-0.86), 0.75 (95% CI = 0.57-0.98), and 0.74 (95% CI = 0.61-0.91), respectively. When the more generally classified "drinkers," were compared with "nondrinkers," they had a reduced risk of AD (RR = 0.66, 95% CI = 0.47-0.94)…
Observational studies usually show that moderate alcohol use is associated with better cognitive function. Such studies are vulnerable to residual confounding arising from systematic differences between moderate alcohol users and others. A Mendelian randomization study carried out in a suitable population, such as southern Chinese men, in which alcohol use is low to moderate and is influenced by genotype, offers an alternative and superior approach for clarifying the causal effect of moderate alcohol use on cognitive function. The authors used aldehyde dehydrogenase 2 (ALDH2) genotype (AA, GA, or GG) as an instrumental variable in 2-stage least squares analysis to obtain unbiased estimates of the relation of alcohol consumption (measured in alcohol units (10 g ethanol) per day) with cognitive function,…
BACKGROUND: There is limited data on the effects of alcohol consumption on cognitive impairment in Chinese populations. OBJECTIVES: To investigate the association between alcohol consumption and the risk of cognitive impairment in Southern Chinese older adults in Hong Kong. METHOD: This was a cross-sectional study of 314 Chinese older participants, aged 65 years or over. Participants' socio-demographic, co-morbid diseases, alcohol drinking habits, and Mini Mental State Examination (MMSE) for cognitive function were obtained by a face-to-face interview. Participants were categorized into normal cognitive and cognitively impaired groups by education-adjusted MMSE cut-off scores. RESULT: The mean (SD) age of the participants was 79.9 (6.5) years. The average weekly alcohol consumption in the cognitively impaired group was significantly higher than that of…
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…

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