Binge drinking may cause damage to DNA
1 January 2014
A preliminary study carried out on university students in Mexico
has found that weekend alcohol consumption causes oxidative damage
to cell membranes and also produces signs of DNA damage in blood
The idea of studying the oxidative effect of weekend alcohol
consumption came about when 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.
The study analysed the effect of alcohol consumption on the
lipids comprising the membrane of cells and DNA. Until now, the damage
to the packaging of nuclear material in the early stages of alcohol
abuse has never been documented, perhaps because most of the studies
are done at later stages with people who have been consuming alcohol
in an addictive way for many years. The results have been published
in the journal Alcohol.
The activity of the enzyme dehydrogenase, which metabolises
ethanol into acetaldehyde, acetoacetate and acetone were measured in
the students. Oxidative damage is evaluated by biochemical test
called TBARS, and reflects the lipid peroxidation that affects the
cell 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 and which can damage cell membrane integrity.
Although the researchers expected to find oxidative damage, they
were surprised by the result, as Adela Rendón explained. “We saw
that the ones who drank sustained twice as much oxidative damage
compared with the group that did not consume alcohol.”
They 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,
which separates the contents across gel using an electric field.
If the chromatin (contents of the cell nucleus) is not properly compacted and the DNA has been
damaged, it leaves a halo in the electrophoresis which is called
'the comet tail'.
In the alcohol-exposed group the chromatin left a small halo that
was 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.
“Fortunately,” Rendón pointed out, “but 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.
The next step would be to study the re-packaging of the chromatin
and the behaviour of complex mechanisms like the histones in these
individuals. “When we talk about youth alcohol abuse, we are
referring to youngsters who drink alcohol without having become
addicted. Addiction involves a more complex issue socially and
psychologically speaking. This is social alcohol abuse,” said Rendón,
“but which causes damage in the long term and you have to be aware
The harmful consumption of alcoholic beverages is a global
problem and constitutes a significant health, social and economic
problem. According to World Health Organisation data, alcohol is
responsible for 2.5 million deaths a year worldwide and youngsters
between the ages of 19 and 25 account for 320,000 of them; it causes
harm that goes beyond the drinker’s physical and mental health.
The effects of alcohol abuse have been mostly studied in people
who have been consuming alcohol for a long time and who therefore
display symptoms ranging from liver damage to various types of
cancer, depression and disorders of the nervous system. That is why
this study is pioneering because it deals with the effect of alcohol
on young, healthy people.
Rendón-Ramírez A, et al. Oxidative damage in young alcohol
drinkers: a preliminary study. Alcohol. 2013 Sept 27.
Rendón Ramírez A, Gelover Reyes E, Couto M, Königsberg M, Castro
P. <<¿Genera Cometas el alcoholismo?>> [Does alcohol abuse generate
comets?] Journal: Bioquimia ISSN 0185-5751. Volume: 29; Issue:
Supplement; Start page: 84; Date: 2004.