Scientists questioned more than 6,500 adults about their past alcohol consumption and assessed their mental abilities over a period of eight years.
They found that a history of problem drinking – described as alcohol use disorders (AUDs) –more than doubled the risk of developing severe memory impairment.
Lead researcher Dr Iain Lang, from the University of Exeter Medical School, said: “We already know there is an association between dementia risk and levels of current alcohol consumption – that understanding is based on asking older people how much they drink and then observing whether they develop problems.
“But this is only one part of the puzzle and we know little about the consequences of alcohol consumption earlier in life. What we did here is investigate the relatively unknown association between having a drinking problem at any point in life and experiencing problems with memory later in life.”
He added: “This finding – that middle-aged people with a history of problem drinking more than double their chances of memory impairment when they are older – suggests... that this is a public health issue that needs to be addressed.”
The findings are published in the American Journal of Geriatric Psychiatry.