【调查】喝咖啡易折寿，喝酒可延年
据英国《每日邮报》报道，以色列的研究人员近期发现咖啡会折寿，而酒精却能延年。特拉维夫的科学家们表示，原因在于咖啡因会缩短染色体DNA的端粒，而酒精却能延长它。端粒能保护染色体的完整，防止它们在细胞分裂的过程中损坏。
端粒随着年龄增长而慢慢缩短，因为每一次细胞分裂，都会把染色体复制到新的细胞中，端粒也就会随之变短。如果端粒变得过短，细胞就会死亡。此外，较短的端粒会引起健康状况不佳，并增加早逝的风险。
研究人员通过酵母细胞来判断环境因素是否对端粒长度有影响。试验表明，温度或者酸碱度（pH值）不会改变端粒长短，但咖啡因，即使是低剂量，也会缩短端粒长度，而酒精却能延长它。“这是我们首次断定一些环境因素会改变端粒的长度，”马丁•库皮埃克教授表示，“我们的研究结果也许日后对疾病防控有所帮助。”
Why you should choose a pint over a coffee: Caffeine can shorten life expectancy - but alcohol lengthens it
Next time you congratulate yourself for choosing a coffee over a beer, you might want to think again.
Researchers have discovered that caffeine can shorten life expectancy, while alcohol can increase it.
Scientists at Tel Aviv University found that caffeine shortens, and alcohol lengthens, telomeres – the end parts of chromosomal DNA.
Just as the plastics tips of shoelaces prevent fraying, telomeres keep chromosomes stable and prevent deterioration when the cells containing them divide.
Telomeres become shorter as a person gets older as every time a cell duplicates, the chromosomes are copied into the new cell with slightly shorter telomeres.When the telomeres become too short, the cell dies.
Shorter telomeres are associated with poor health and an increased chance of premature death.
‘For the first time we've identified a few environmental factors that alter telomere length, and we've shown how they do it,’ said Professor Martin Kupiec. ‘What we learned may one day contribute to the prevention and treatment of human diseases.’
The researchers set out to establish if different environmental factors had an impact on telomere length in yeast cells.
They found temperature and pH changes had no effect.However, they found that telomere length was reduced by even low levels of caffeine, while it was increased by alcohol.
The researchers say that even an espresso contains enough caffeine to affect telomere length, as does five per cent ethanol solution.
To understand these changes, the researchers scanned 6,000 strains of the yeast, each with a different gene deactivated.
They then conducted genetic tests on the strains with the longest and shortest telomeres, revealing that two genes, Rap1 and Rif1, are the main players controlling environmental factors and telomere length.
In total, some 400 genes interact to maintain telomere length, they noted, underscoring the importance of this gene network in maintaining the stability of the genome.
Strikingly, most of these yeast genes are also present in the human genome.
‘This is the first time anyone has analysed a complex system in which all of the genes affecting it are known,’ said Professor 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.’(MailOnline)
端粒随着年龄增长而慢慢缩短，因为每一次细胞分裂，都会把染色体复制到新的细胞中，端粒也就会随之变短。如果端粒变得过短，细胞就会死亡。此外，较短的端粒会引起健康状况不佳，并增加早逝的风险。
研究人员通过酵母细胞来判断环境因素是否对端粒长度有影响。试验表明，温度或者酸碱度（pH值）不会改变端粒长短，但咖啡因，即使是低剂量，也会缩短端粒长度，而酒精却能延长它。“这是我们首次断定一些环境因素会改变端粒的长度，”马丁•库皮埃克教授表示，“我们的研究结果也许日后对疾病防控有所帮助。”
Why you should choose a pint over a coffee: Caffeine can shorten life expectancy - but alcohol lengthens it
Next time you congratulate yourself for choosing a coffee over a beer, you might want to think again.
Researchers have discovered that caffeine can shorten life expectancy, while alcohol can increase it.
Scientists at Tel Aviv University found that caffeine shortens, and alcohol lengthens, telomeres – the end parts of chromosomal DNA.
Just as the plastics tips of shoelaces prevent fraying, telomeres keep chromosomes stable and prevent deterioration when the cells containing them divide.
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Telomeres become shorter as a person gets older as every time a cell duplicates, the chromosomes are copied into the new cell with slightly shorter telomeres.When the telomeres become too short, the cell dies.
Shorter telomeres are associated with poor health and an increased chance of premature death.
‘For the first time we've identified a few environmental factors that alter telomere length, and we've shown how they do it,’ said Professor Martin Kupiec. ‘What we learned may one day contribute to the prevention and treatment of human diseases.’
The researchers set out to establish if different environmental factors had an impact on telomere length in yeast cells.
They found temperature and pH changes had no effect.However, they found that telomere length was reduced by even low levels of caffeine, while it was increased by alcohol.
The researchers say that even an espresso contains enough caffeine to affect telomere length, as does five per cent ethanol solution.
To understand these changes, the researchers scanned 6,000 strains of the yeast, each with a different gene deactivated.
They then conducted genetic tests on the strains with the longest and shortest telomeres, revealing that two genes, Rap1 and Rif1, are the main players controlling environmental factors and telomere length.
In total, some 400 genes interact to maintain telomere length, they noted, underscoring the importance of this gene network in maintaining the stability of the genome.
Strikingly, most of these yeast genes are also present in the human genome.
‘This is the first time anyone has analysed a complex system in which all of the genes affecting it are known,’ said Professor 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.’(MailOnline)
