August 12, 2017

Findings differ on relationship between drinking and dementia

Researchers say moderate drinking could prevent dementia and cognitive decline in general.

Others claim the opposite.

Two studies published in recent weeks did what studies often do – give two starkly different conclusions on the same topic.

At the University of California-San Diego, a study of 1,344 older adults in the San Diego suburb Rancho Bernardo defined "moderate and heavy" as having up to three drinks a day in women and four drinks a day in men. That July 29 report found that moderate and heavy drinkers were twice as likely to live to age 85 without cognitive impairment compared to non-drinkers.

The study followed 1,344 older adults in the San Diego suburb Rancho Bernardo between 1984 and 2013, and it defined "moderate and heavy" as having up to three drinks a day for women and four drinks a day in men.

But research from the University of Oxford suggests that regularly drinking a moderate amount of alcohol can increased risk of developing cognitive diseases.

That study tracked 550 middle-aged men and women between 1985 and 2015, and used brain imaging. The heaviest drinkers (30 or more drinks each week) were at the highest risk, while even those who drank a moderate 14 to 21 drinks per week were three times as likely to develop right-side hippocampal atrophy, a condition associated with dementia and Alzheimer's.

The Oxford researchers admitted that "results of research into the effects of moderate alcohol on the brain are inconsistent." They also said past studies that have used brain imaging have thus far failed to provide a convincing neural correlate that could underpin any protective effect."

The California study pointed out that very few of its subjects drank too much.

"Our study does not show how excessive or binge-type drinking may affect longevity and cognitive health in aging," co-author Linda McEvoy said in a Decanter report on both studies.

Researchers also stressed that drinking isn't directly related to living longer and without cognitive diseases.

They also noted that alcohol, particularly wine, is linked with higher incomes and education, which are in turn linked with lower rates of smoking and better health care.

Read more on both studies here.