How was the correlation studied?
To study alcohol intake for each person, researchers had participants fill out a questionnaire about their drinking habits. Next, they evaluated their cognitive abilities over the next 2 decades using a special interview test called the Mini-Mental State Examination, or MMSE. This test is a 5-component test that examines someone’s short-term memory, long-term memory, attention, orientation, and language. Participants were followed every 4 years for a total of 6 evaluations.
As endpoint measurements, the researchers looked at rates of death before age 85 as well as cognitive impairments later in life. They compared these rates between people who didn’t drink, people who drank moderately, and those who drank heavily. Heavy drinking was based on gender and sex. Women and older men above the age of 65 were considered heavy drinkers if they consumed over 3 drinks daily. For men below age 65, heavy consumption was more than 4 drinks per day.