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.