Coffee or Beer? The Choice Could Affect Your Genome

Coffee and beer are polar opposites in the beverage world. Coffee picks you up, and beer winds you down.

Now Prof. Martin Kupiec and his team at Tel Aviv University's Department of Molecular Microbiology and Biotechnology have discovered that the beverages may also have opposite effects on your genome. Working with a kind of yeast that shares many important genetic similarities with humans, the researchers found that caffeine shortens and alcohol lengthens telomeres -- the end points of chromosomal DNA, implicated in aging and cancer.

"For the first time we've identified a few environmental factors that alter telomere length, and we've shown how they do it," said Prof. Kupiec. "What we learned may one day contribute to the prevention and treatment of human diseases."

The researchers set out to expand on a 2004 study by Nobel Prize-winning molecular biologist Prof. Elizabeth Blackburn, which suggested that emotional stress causes the shortening of the telomeres characteristic of aging, presumably by generating free radicals in the cells. The researchers grew yeast cells in conditions that generate free radicals to test the effect on telomere length. They were surprised to find that the length did not change.

They went on to expose the yeast cells to 12 other environmental stressors. Most of the stressors -- from temperature and pH changes to various drugs and chemicals -- had no effect on telomere length. But a low concentration of caffeine, similar to the amount found in a shot of espresso, shortened telomeres, and exposure to a 5-to-7 percent ethanol solution lengthened telomeres.