alcohol

A mouse study found that high levels of alcohol over a long period of time were associated with high levels of a marker for inflammation, along with impaired cognition and motor skills.

However, those exposed to low levels of alcohol consumption, analogous to approximately 2 ½ drinks per day, actually showed less inflammation in the brain and their glymphatic system was more efficient in moving CSF through the brain and removing waste, compared to control mice who were not exposed to alcohol. Their cognitive performance also matched that of the controls.

A British study following 550 adults over 30 years from 1985 has found that those who reported higher levels of alcohol consumption were more often found to have a shrunken hippocampus, with the effect greater for the right side of the brain. Such shrinkage was found in 35% of those who didn’t drink, but 65% for those who drank an average 2-3 units daily, and 77% for those who drank 30 or more units a week.

The structure of white matter was also linked to how much individuals drank.

Research using human cell cultures and mice suggests that those with an uncommon variation of the aldehyde dehydrogenase 2 gene (ALDH2) may be more at risk of Alzheimer's if they consume alcohol. This gene variation is associated with facial redness following alcohol consumption, reflecting reduced activity of an enzyme that protects against a toxin produced by alcohol consumption (acetaldehyde). Flushing, and inflammation, is a response to the toxin.

A 10-year study involving 19,887 middle-aged and older Americans, who completed surveys every two years about their health and lifestyle, has found that those who had a drink or two a day tended to show less cognitive decline, compared to non-drinkers.

Cognitive function was measured in a series of tests looking at their overall mental status, word recall and vocabulary. Their test results were combined to form a total cognitive score.

Age, smoking and education level were controlled for.

Data from 196,383 older adults (60+; mean age 64) in the UK Biobank found that a healthy lifestyle was associated with lower dementia risk regardless of genes.

Both an unhealthy lifestyle and high genetic risk were associated with higher dementia risk.

Large study shows level of beneficial alcohol consumption much lower than thought

A UK study using data from 13,342 middle-aged and older adults (40-73) has found that having up to one standard unit of alcohol a day improved reaction time, but more than that amount harmed cognitive performance. The effect was more pronounced in older adults.

How alcohol increases Alzheimer's risk

A cell-culture study using rodent microglia found that some of the genes affected by alcohol and inflammation are also implicated in processes that clear amyloid beta, suggesting that alcohol may impede the clearance of amyloid beta in the brain.

A pilot study involving 106 participants of the Rush Memory and Aging Project who had experienced a stroke followed participants for an average of 5.9 years, testing their cognitive function and monitoring their eating habits using food journals. It was found that those whose diets scored highest on the MIND (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay) diet score had substantially slower rates of cognitive decline than those who scored lowest.