Tel Aviv University researchers: Coffee and beer may destabilize your genome
Caffeine and alcohol affect cellular aging, genome stability and the risk for different diseases researchers say.
By JUDY SIEGEL-ITZKOVICHBeer mugs 370(photo credit: Reuters)
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 diseases.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.Prof. Martin Kupiec and his team pointed specifically to caffeine, which seems to shorten telomeres, and alcohol, which appears to lengthen them.Caffeine 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 Yaniv Harary.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 telomeres.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.“Telomeres shorten 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 shortening.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.Because 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 said.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 the genome.“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 the field.”
