Heavy drinking during a man's middle-aged years may hasten memory loss by up to six years later on in life, researchers from University College London found in a study of more than 7,000 people.

Published in the journal Neurology, the study, which included 5,054 men and 2,099 women, defined heavy drinking as more than 36 grams of alcohol per day, or roughly two pints of beer. 

Each participant's drinking habits were assessed three times during the course of 10 years. When they reached an average of 56 years old, they were given tests that evaluated memory and executive function, such as problem-solving and attention. These tests were administered twice over the next decade.

The results revealed no differences between men who did not drink and light or moderate drinkers, or those who consumed less than 20 grams per day. However, heavy drinkers exhibited declines in both memory and executive function between one and half to six years sooner than the rest.

"Much of the research evidence about drinking and a relationship to memory and executive function is based on older populations," said study author Séverine Sabia, PhD, of the University College London in the United Kingdom. "Our study focused on middle-aged participants and suggests that heavy drinking is associated with faster decline in all areas of cognitive function in men."

Women did not follow the same pattern; though, the researchers noted in the study that heavy alcohol in women was half that seen in men. There were also different social patterns associated with heavy drinking in women, such as women who drank more being more likely to occupy a higher position at work - a theme not seen in the men.

"Thus, the interpretation of sex differences in our study is not straightforward and further research is needed to test whether the effect of alcohol on cognition differs by sex," they concluded.