Drinking more than two-and-a-half drinks a day can speed memory loss by up to six years, a study of middle aged men in Britain found. Moderate drinking, on the other hand, did not show harmful effects on memory and thinking skills in later years.
The findings, which were published in Neurology, from the American Academy of Neurology, add to earlier research showing that heavy drinking is bad for the brain.
“Much of the research evidence about drinking and a relationship to memory and executive function,” which allows us to plan, solve problems and perform other mentally demanding task, “is based on older populations,” said study author Séverine Sabia, 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.”
For the study, researchers looked at more than 5,000 men and 2,000 women whose drinking habits were assessed three times over a 10-year period. Those who said they had had beer, wine or liquor in the previous year but not in the previous week were classified as occasional drinkers; those who had about 15 drinks or less per week were moderate drinkers; and those who drank more than that weekly, or about two-and-a-half drinks a day on average, were classified as heavy drinkers.
The researchers did not distinguish between daily drinkers and binge drinkers, who may drink heavily only on weekends, for example. But most of the heavy drinkers in the study said they drank daily or almost daily.
At an average age of 56, the study participants were given a test to assess memory and thinking skills. They were assessed for memory and thinking abilities two more times over the next 10 years.
The researchers found that those men who did not drink at all or who were light or moderate drinkers did not show any difference in declines in memory or reasoning and planning skills. Men who were heavy drinkers, though, showed memory and executive function declines between one-and-a-half to six years faster than those who had fewer drinks per day. The more the men drank, in general, the greater the decline in cognitive function, the researchers found.
Patterns of drinking and memory declines were less consistent among the women in the study, though the researchers found slight declines in executive function in women who drank heavily compared to those who drank less. They also found that women who drank moderately showed less cognitive decline than those who abstained from alcohol.
Some earlier studies have shown that light to moderate drinking may be linked to less cognitive decline and a lower risk of dementia. Wine, in some studies, was shown to have more brain benefits than other types of alcohol. However, most of those studies were conducted in older people, including those whose heavy drinking may have caused a variety of health ills. This study looked at younger men and women who ranged in age from 44 to 69 at the study’s start, assessing declines in thinking and memory over the next decade.
The authors note that light to moderate alcohol consumption is associated with better health of the heart and blood vessels, while excessive alcohol consumption is tied to worse cardiovascular health. Improved vascular health in the brain may account for some of the observed benefits in this study, they note.
Alcohol abuse can also impair memory because excessive alcohol may be toxic to nerve cells. Those who drink alcohol also often show vitamin deficiencies, including those of B vitamins essential for nerve and brain function.
Source: Severine Sabia, PhD, Alexis Elbaz, MD, PhD, Annie Britton, PhD, et al: “Alcohol Consumption and Cognitive Decline in Early Old Age.” Neurology, Vol. 82, pages 332-339, January 15, 2014.