Moderate drinking has been thought to be harmless – until now. Researchers from the University of Oxford and University College London studied the weekly alcohol intake and cognitive performance tests of 550 healthy men and women over a 30-year period (1985-2015). The average age of the participants was 43 years at the start of the study and none of the participants were dependent on alcohol. After controlling for various factors such as age, gender, physical activity, and others, aspects of cognitive performance were measured at six points over the 30 years. The researchers then performed MRI scans of the participants’ brains. The overall research results showed (1) that participants who reported higher levels of alcohol consumption were at an increased risk of having hippocampal atrophy, impairing memory and spatial navigation; (2) that participants who drank more than 30 units of alcohol were at the greatest risk and participants who consumed a moderate amount of alcohol (14 to 21 units) were at three times the risk of those who did not drink at all; and (3) higher levels of drinking were associated with diminished white matter integrity, reducing efficient cognitive function and lexical fluency.