Consumption
of two common beverages - coffee and beer - may influence a person's life
expectancy.

Experiments conducted by
researchers from Tel Aviv University in Israel showed that coffee and beer
left opposite effects on the length of telomeres - the sections of DNA found at
the ends of chromosomes. While caffeine decreased length of telomeres, ethanol
helped improve it.

Telomeres manage the ageing process by playing a major role in the division
of cells. The length of telomeres becomes shorter with each stage of cell
division. The process continues until the telomeres become too short, leading to
cell death and ageing. Telomere shortening
has long been known to damage immunity and increase risk of cancer.

Prof. Martin Kupiec and colleagues
started their study as an investigation into Prof. Elizabeth Blackburn's (Nobel Prize-winning molecular
biologist) 2004 study that linked emotional stress to shortening of telomere
length, ageing and production of free radicals in the cells.

In the new study, Kupiec and team grew yeast cells and created free radicals.
The yeast cells were exposed to 12 environmental stressors, including caffeine
and ethanol. Even a small exposure to caffeine was found affecting the length of
telomeres. On the other hand, exposure to ethanol left a positive impact on the
length.

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

While conducting further experiments, researchers identified two genes - Rap1
and Rif1 that play a major role in mediating between telomere length and
environmental stressors. "This is the first time anyone has analyzed a complex
system in which all of the genes affecting it are known," said Prof. Kupiec. "It
turns out that telomere length is something that's very exact, which suggests
that precision is critical and should be protected from environmental
effects."

Findings have been published in PLOS Genetics.

• 圖片
• 影片
• 部落格
• 購物
• 商家
• 新聞

• 字典
• 名人娛樂
• 食譜