Heavy drinking shrinks the brain

Washington:US researchers have revealed that heavy, chronic drinking can cause significant damage to a part of the brain structure which is vital to learning and memory.

Their study reveals that the volume of hippocampal tissue in the brain reduces over the years in heavy drinkers.

The researchers examined the effect of alcohol on the hippocampus and found that heavy drinking can reduce total hippocampus volume, which likely reflects a loss of hippocampal tissue substance.

“The hippocampus actually refers to two structures, the right hippocampus and the left hippocampus that are located in the right and left temporal lobes of the brain. Most scientists think that the hippocampus helps the brain manage learning, especially learning and remembering new things or things that happened recently. Before this study, researchers had noticed that the volume of the hippocampus seemed to be smaller in people who frequently drank large amounts of alcohol for long periods of time.” explained Thomas P. Beresford, Department of Veterans Affairs physician, and professor of psychiatry at the University of Colorado Health Sciences Center.

The researchers used magnetic resonance imaging (MRI) scans to compare hippocampus volumes among non-alcoholics and heavy drinkers.

Study results indicated a reduction in total hippocampus volume among the alcoholics.

“When we took a picture of the alcoholic brains using MRI, and measured the hippocampus,” said Beresford, “it was much smaller than the hippocampus in the group of people who did not drink alcohol heavily. This means that alcohol appears to injure the hippocampus by itself. That is, it may harm the hippocampus in a way that other things do not.”

The findings of the study could explain some of the memory impairment and cognitive deficits described in chronic alcoholics, but it is not clear whether the effect is reversible.

“This study is only a first step. We are now studying what happens to the hippocampus in heavy drinkers when they stop drinking, whether the hippocampus heals itself or not, and what we might do to help healing along. Since the hippocampus is connected to many other parts of the brain, it is difficult to know all of the things that it does. Most scientists think that injury to the hippocampus makes it harder to learn things, especially to keep memories of new things or of new patterns. Understanding this, and how alcohol-dependent individuals may cope and even heal, is the point of our research,” he said.

The results of the study are published in the November issue of Alcoholism: Clinical & Experimental Research.