Page last updated: November 27, 2013

Heavy alcohol consumption leaves its mark on youngsters’ DNA

A study begun in Mexico with the collaboration of university students analysed the effect of weekend alcohol consumption on the lipids comprising cell membrane and its genetic material, i.e. DNA. The results have been published in the journal Alcohol.

The authors state that the study is pioneering because it deals with the effect of alcohol on young, healthy people. The damage to the packaging of nuclear material in the early stages of alcohol consumption has never been documented, perhaps because most of the studies are done at later stages with people who have been consuming alcohol for many years.

The idea of studying the oxidative effect of weekend alcohol consumption came about when the researcher Adela Rendón was lecturing in Clinical Biochemistry at the National Polytechnic Institute in Mexico. Many of the students turning up for class first thing on Monday morning displayed a lack of attention and general malaise due to having drunk alcohol over the weekend. The researcher suggested to them that they should study the effects on their bodies of the weekend consumption that the students regarded as harmless. A study was therefore initiated to examine oxidative damage caused by the consumption of high levels of alcohol consumption in young people.

The students were divided into two groups: the control group made up of the students who did not drink alcohol and the study group of those who drank heavily at weekends. To make sure that they were healthy individuals without any other diseases or addiction that could alter the results of the study, they underwent blood tests. The age of the students ranged between 18 and 23 and the average consumption of alcohol was 118g, considerably more than responsible daily drinking guidelines for adults of between 14g and 24g for women and 28g and 40g (depending on country guidelines). The activity of the alcohol enzyme dehydrogenase, responsible for metabolising ethanol into acetaldehyde, acetoacetate and acetone was measured. Oxidative damage is evaluated by a TBARS biochemical test (types that react to barbituric acid), and reflects the lipid peroxidation that affects the membrane due to the impact not only of the ethanol in the blood but also of the acetaldehyde produced by the action of the enzyme on the ethanol. Therefore, there are at least two means by which free radicals are formed that can damage cell membrane integrity.

Although the researchers expected to find oxidative damage, they were surprised by the result. The group who drank sustained twice as much oxidative damage compared with the control group. The researchers then decided to continue with a test to assess whether the DNA was also affected: the comet test. They extracted the nucleus of the lymphocytic cells in the blood and subjected it to electrophoresis. If the DNA has been damaged, it leaves a halo in the electrophoresis which is called, “the comet tail”. The chromatin of the exposed group left a small halo, greater than that of the control group. The results revealed damage in 8% of the cells in the control group and 44% in the exposed group. Therefore, the exposed group had 5.3 times more damaged cells.

To be able to confirm the existence of considerable damage to the DNA, the comet tail must exceed 20 nm, and that was not the case. Rendón commented “… the fact is, there should not have been any damage at all because they had not been consuming alcohol for very long, they had not been exposed in a chronic way.” The means by which alcohol manages to alter DNA is not yet known. Source: Adela Rendón-Ramírez, Miriam Cortés-Couto, Abril Bernardette Martínez-Rizo, Saé Muñiz-Hernández, Jesús Bernardino Velázquez-Fernández. Oxidative damage in young alcohol drinkers: A preliminary study. Alcohol, 2013; 47 (7): 501 DOI: 10.1016/j.alcohol.2013.08.002.

 

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