Diet, and not only the environment and physiological changes, may have an
influence on the length of telomeres – the nucleoprotein caps on the ends of
chromosomes that are implicated in cellular aging, cancer and other
This has been discovered for the first time in tests on yeast
cells in the lab – though not yet on animals or humans – by researchers at Tel
Aviv University, who have just published their findings in the prestigious,
open-access journal PLOS (Public Library of Science) Genetics.
Martin Kupiec and his team pointed specifically to caffeine, which seems to
shorten telomeres, and alcohol, which appears to lengthen them.
and alcohol affect cellular aging, genome stability and the risk for different
diseases, said Kupiec and other members of his team, Dr. Gal Hagit Romano and
They tested how different environmental stressors affect
elements of the genome in living yeast cells that are used for making bread and
beer. Their results show that caffeine and alcohol alter the length of
In the last decade, groups around the world have studied the
impact that environmental factors (the food we eat and the chemicals to which we
are exposed) have on the human genome.
Recently, telomeres have become a
particular focus of attention.
Telomeres are essential for chromosome
stability and replication. They protect chromosome ends from breaking down and
prevent degradation and rearrangement of chromosomes.
with each cell division and thus constitute a ‘molecular clock’ that underlies
cellular aging,” said Kupiec on Thursday.
“Cancer cells elongate their
telomeres to become immortal.”
In a 2004 study, Nobel laureate Prof.
Elizabeth Blackburn surprised the world by demonstrating that mental stress
correlates with telomere length. She maintained that there is a correlation –
but not a proven cause and effect – between prolonged mental stress in women and
shorter telomeres in their cells.
Until now, said Romano, the common
assumption was that due to mental stress, physiological changes – accumulation
of free radicals and oxidative stress, for example – occurred, causing telomere
To test this assumption, Kupiec’s team grew cells under
oxidative stress. Surprisingly, telomere length was not changed. The team then
exposed cells to 13 different environmental stressors (temperature and pH
changes, different drugs and chemicals).
Although most treatments had no
impact on telomere length, several compounds with which humans have daily
encounters significantly altered telomere length. A low concentration of
caffeine, similar to the amount found in one shot of espresso, for example,
significantly shortened telomeres, while exposure to a 5 percent to 7 percent
alcohol solution disrupted the mechanism maintaining telomere length, resulting
in long and heterogeneous telomeres.
The Kupiec team’s research has major
therapeutic consequences, explains PhD student Yaniv Harary. Due to telomeres’
importance in preserving genome stability, telomere length is controlled by a
complex genetic network.
More than 400 genes affect telomere length and
create a stable system capable of coping with environmental changes. Disrupting
that system and altering telomere length may cause genome instability, rapid
aging, and the development of a host of different diseases.
alterations in telomere length may fuel the pathology of many human diseases,
controlling telomere length by manipulating simple stressing agents may point
the way to effective treatment, said Kupiec, who said it is too early – maybe
many years – before scientists will be able to recommend eating or drinking
certain things to balance out their telomeres.
“There are open biological
questions. So far, there is correlation but not proven cause and effect. There
is a connection between the shortening of telomeres and aging, but we don’t know
if one causes the other or one is only a marker of the other,” he
Asked to comment, Rambam Medical Center and Technion genetics
researcher Prof. Karl Skorecki, who is also director of the Technion’s Rappaport
Research Institute, commented that the TAU study was “a very interesting and
carefully done study by an excellent group of investigators, which has found a
potentially important additional pathway whereby environmental cues influence
“Since the discovery is based on studies in a biological
model system, it may be too early to draw direct human inferences and make
clinical recommendations. However, the principle of dietary and environmental
influence on the genome and especially the rate of shortening at the ends of
chromosomes is of crucial importance.
“Furthermore, by unraveling pivotal
control pathways whereby these effects occur, the investigators have advanced