Alcohol Damages White Matter in Brain, Affects Critical Thinking
People who drink heavily must work substantially harder on critical thinking tasks to achieve the same results as people unaffected by alcohol problems due to changes in the white matter in their brains, a new study finds.
Changes in the health of white matter were recently compared among people affected by alcohol dependence (alcoholism) and among problem drinkers unaffected by issues of dependence. White matter is the common name for a type of nerve cell tissue found in the brain that provides the basic connectivity required for the brain to function as the body’s central-processing organ. Significant damage to this tissue can cause malfunctions in a wide array of key activities that keep the body working properly.
Alcoholism and the Brain
Alcoholism is the result of a long-term process that begins with the excessive consumption of alcohol. Among its other effects, alcohol triggers euphoric sensations in a part of the brain commonly referred to as the pleasure center. It is this euphoric feeling that helps explain why some people consume the substance in heavy amounts. Unfortunately, when the pleasure center repeatedly experiences exposure to large amounts of alcohol, this brain area undergoes a chemical transformation and starts to depend upon an ongoing alcohol supply. Functionally speaking, such a physical dependence on alcohol is the same as alcohol addiction or alcoholism. People affected by dependence/alcoholism typically experience a range of symptoms that can include loss of the ability to limit alcohol intake, the presence of strong cravings that reinforce the need to consume alcohol, a reduced brain effect from the consumption of any given quantity of alcohol (i.e. alcohol tolerance) and the appearance of withdrawal if alcohol intake fails to meet the minimum intake dictated by dependence.
Alcoholism can have a direct or indirect impact on brain health. Known direct effects of the condition include impaired logic skills, memory impairment, brain shrinkage and loss of functional efficiency in the central nervous system (brain and spinal cord). Vitamin B1-related nutritional problems associated with alcoholism can have indirect brain effects that include the onset of the severe and potentially fatal combination of nerve cell damage, amnesia, impaired body balance and delusional thinking known as Wernicke-Korsakoff syndrome.
White matter is similar to the electrical cables that bring power to a neighborhood. The power must leave the cables in order to be useful, but without the cables, no one has access to the power. In this analogy, the brain’s main nerve cells—known formally as neurons and informally as gray matter—play the role of the vital devices that need power in order to work properly. White matter connects the individual cells in gray matter together and helps provide the brain with its fundamental ability to send and receive the signals that form the body’s command and control network.
Changes in People With Alcohol Problems
In a study published in December 2014 in Addiction Biology, researchers from the Amsterdam Institute for Addiction Research, the University of Amsterdam and several other Dutch institutions used a brain imaging technology called fMRI (functional magnetic resonance imaging) to examine the white matter health in people diagnosed with alcoholism, as well as in people who have drinking problems but don’t qualify for an alcoholism diagnosis. A total of 71 adults took part in this project. Twenty-six of these participants were dependent on alcohol, while 23 had significant, non-addiction-related alcohol issues. A third group of 22 adults acted as a comparison group and had no alcohol-related difficulties.
The researchers asked the members of all three groups to perform critical thinking tests while simultaneously undergoing real-time fMRI scans. When they reviewed the results of the tests, they found that the alcoholism-affected participants, the non-addicted group of people with alcohol problems and the comparison group performed equally well. However, when the researchers looked closely at the fMRI results, they concluded that the drinkers’ brains had to work substantially harder to achieve good testing results than the brains of the people in the comparison group. They also concluded that the underlying reason for this added workload was damage in the functional integrity of the drinkers’ white matter.
The study’s authors concluded that people affected by alcoholism have more difficulty than their counterparts dealing with non-addiction-related alcohol problems when it comes to recruiting the extra mental resources required to maintain brain function.