17 October, 2008

Moderate Alcohol Consumption Shrinks Brain

We have been told that moderate use of alcohol is good for the heart. However, reports from the Framingham Study show that moderate to heavy alcohol use is associated with damage to brain tissue. Such damage to the brain may lead to higher risk of stroke or dementia.

The Framingham Study began in 1948 to follow the residents of Framingham, Massachusetts and their offspring. The study is now following a third generation of participants. The goal of the study is to follow people over a long period of time, documenting their state of cardiovascular disease.

At the beginning of the study, subjects have no evidence of heart disease. The subjects are put through a series of tests every two years. Over time, medical records are analyzed to determine risk factors for cardiovascular disease. Much of the information published about risk factors for heart disease and stroke comes from this study.

The American Academy of Neurology presented evidence in 2007 from Wellesley College, Massachusetts. Carol Ann Paul M.S. and her associates reported that even moderate amounts of alcohol are associated with brain atrophy and possibly an increased risk of dementia or stroke.

Researchers performed MRI scans on 1,839 people aged 34 to 88 to compare the volume of brain tissue to their cranial size. Subjects were classified as non-drinkers, former drinkers, low drinkers (1 to 7 drinks per week), moderate drinkers (8 to 14 drinks per week), or high drinkers (more than 14 drinks per week). Brain shrinkage numbers increased by .25 percent as amount and frequency of drinking increased. People who consumed more than 14 drinks per week had brains which averaged 1.6 percent smaller than those who did not drink alcohol. For women, especially those in their 70's, the change was more dramatic than for men. Researchers speculated that the differences may be associated with the smaller body mass of women. In addition, those who had a longer history of heavy alcohol consumption also had more brain atrophy. The team noted that men were more likely to become heavy drinkers than women.

The same group reported again in 2008 in the Journal of the American Medical Association: "The public health effect of this study gives a clear message about the possible dangers of drinking alcohol," the authors write. "... This study suggests that, unlike the associations with cardiovascular disease, alcohol consumption does not have any protective effect on brain volume.” They suggest further, longer term studies to determine the full impact of these findings.

In general, brain volume decreases with age at an estimated rate of 1.9 percent every ten years. At the same time white matter lesions replace grey matter. Lower brain mass and white lesions are associated with problems in movement, thinking, learning, and memory.

A 2006 study from the Erasmus Medical Center in Rotterdam observed that people who developed dementia decreased in brain volume between 5 and 17 percent during the eight year study. Those who were diagnosed with Alzheimer’s had a decrease up to 40 percent. People with atrophy in parts of the brain known as the amygdala and hippocampus had the highest risk of developing dementia or Alzheimer's disease.

The accelerated loss of grey matter under the influence of alcohol is worth considering before you down that second (or third) serving of spirits.


JAMA and Archives Journals (2008, October 14). Drinking Alcohol Associated With Smaller Brain Volume. ScienceDaily. Retrieved October 16, 2008, from http://www.sciencedaily.com/releases/2008/10/081013171421.htm

Johns Hopkins University Bloomberg School Of Public Health (2003, December 5). Moderate Alcohol Consumption Linked To Brain Shrinkage. ScienceDaily. Retrieved October 16, 2008, from http://www.sciencedaily.com/releases/2003/12/031205052952.htm

American Academy of Neurology (2007, May 3). Drinking Heavy Amounts Of Alcohol Shrinks Your Brain. ScienceDaily. Retrieved October 16, 2008, from http://www.sciencedaily.com/releases/2007/05/070502172317.htm



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