A study presented this week in Boston suggests that the greater a person’s alcohol consumption over time, the more the brain shrinks in size.
Carol Ann Paul, a postgraduate researcher from Wellesley College in Massachusetts, who conducted the study, said yesterday “Research has shown that there is a beneficial effect of alcohol in reducing incidence of cardiovascular disease in people who consume low to moderate amounts of alcohol. However, this study found that greater alcohol consumption was negatively correlated with brain volume.”
Researchers in the study looked at the MRI brain scans of 1,839 people ages 34 to 88. Based upon self-report, the research subjects were classified as non-drinkers, former drinkers, low drinkers (those who drank one to seven drinks per week), moderate drinkers (eight to 14 drinks per week), or high drinkers (more than 14 drinks per week).
Excessive drinking appears to accelerate the natural reduction in brain size caused by aging. The researchers found that the more alcohol people drank on a regular basis, the smaller their brain volume. People who had more than 14 drinks per week had an average 1.6 percent reduction in brain volume compared with people who never drank, especially among older women.
Brain volume decreased 0.25 per cent on average for every jump in drinking category. There is a natural reduction of about 0.19 per cent every year due to ageing, researchers said. Women were found to have a reduction of up to 0.29 per cent for every jump in category; for men it was 0.2 per cent.
The researchers, however, did not test perfomance on mental assessments that help determine whether such size differences makes a real difference in how a person thinks, behaves, or feels.
People who participated in the research study had an average age of 60, with a brain-to-skull ratio of under 80 per cent of what it was when they were young adults. Previous studies have suggested that alcohol-dependent people have smaller brain volumes than others. It is believed that this is due to ethanol, which causes an alcoholic’s brain to shrink with aging to a greater extent.
The unpublished findings were presented to the American Academy of Neurology conference in Boston.