送交者: blackbox 于 2006-5-23, 15:26:27:
回答: ZT:英国科学家研究基因得惊人结论：贫穷竟是天注定 由 xinku 于 2006-5-23, 10:32:27:
Doomed to failure by 'poverty gene'
RICHARD GRAY HEALTH CORRESPONDENT ( rgray@scotlandonsunday.com)
SCOTTISH scientists have discovered a "poverty gene" which causes people from deprived areas to age rapidly, pass on health problems to the next generation and might even explain negative attitudes to employment.
Research in Glasgow has established that deprivation can lead to an overactive immune system which quickly uses up the body's supply of spare cells needed to keep ageing at bay. It means a typical 55-year-old from the city's East End might have a "biological age" closer to 70.
Centuries of natural selection among poor communities mean those with highly active immune systems are more likely to pass their genes on, condemning the next generation to grow old before their time.
Most astonishing of all, it is suspected that a hyperactive immune system floods the brain with a cocktail of chemicals which suppress the natural desire for self-advancement.
The study, by the Glasgow Centre for Population Health, is the first time the full extent of the link between health, genetics and poverty has been looked at scientifically. The findings have been seized upon by health campaigners as evidence that poverty is not simply the result of idleness and that more resources should be ploughed into tackling health inequality to break the cycle of deprivation.
But fears have also been expressed that linking poverty to genetic traits could have the opposite effect by encouraging the view that the poor should be abandoned as a lost cause.
Scotland has one of the worst health records in the western world, with shockingly high levels of chronic illnesses such as heart disease, obesity, cancer and diabetes.
There are enormous health gaps within Scotland, with men living in Glasgow's East End expected to die by the age of 64 while in Orkney life expectancy is 82.
Initial findings from the new research have shown that those from poorer areas are hit with a 'double whammy' of unhealthy environmental factors and an inherited predisposition to poor health.
Dr Chris Packard, a biochemist and principal investigator in the study, said: "We are looking at the idea that these people suffer from a chronic state of inflammation where their immune systems are constantly on a high state of alert.
"Compounds called cytokines, which talk to other parts of the immune system to prepare it for the invasion of bacteria, are far higher in people from deprived areas compared with the more affluent ones.
"This constant state of alert seems to be prematurely ageing the body beyond chronological age and so accelerates chronic diseases - they are, in a sense, old beyond their years."
Packard believes this overactive immune system has developed in poorer communities by being inherited over generations.
He claims that children with more aggressive biological defences were better able to survive potentially deadly Victorian-era diseases such as measles and so were able to pass on this trait to their own children.
This has led to large swathes of deprived communities who have lived for generations in the same area, now suffering from high levels of immune activity. While this can provide protection during childhood against diseases, it causes additional stress to the body in adulthood, which causes it to age far faster.
This ageing process can be gauged by measuring the growing thickness of artery walls. The team are also studying the spare DNA that helps cells to replicate to repair tissue damaged by wear and tear. With each replication this DNA reduces, and once it is gone the cells can no longer replicate, meaning tissues degenerate.
Packard said: "If you look at a person from the East End of Glasgow aged 55, they may look closer to 65 or 70, while those from a more affluent area of the same age will probably be far closer to their real age."
The researchers are also conducting brain scans on individuals in a bid to unravel the effect this high-level immunity has on their psychology.
Packard added: "Cytokines also affect mood and an individual's general mental outlook to make them feel very negative about their life. This may explain why people from these deprived backgrounds feel they are trapped in poverty and are unable to see the benefits of changing their lifestyle to improve their health. They feel very negatively about life and cannot see the point in trying to extend it."
The researchers now hope to find new ways of helping people from deprived areas to improve their health.
Shona Robison, SNP shadow health minister, said it was important the government made it easier for poorer people to pull themselves out of poverty. "My concern is that we don't start pushing responsibility for dealing with poverty and poor health on to individuals themselves," she said. "We can't write off whole generations of families as being damaged by poverty, as given support through improved economic conditions and education, they can turn their lives around."
But Lord Tebbit, the former Trade and Industry Secretary who famously urged the unemployed to "get on their bikes", said he did not believe poverty could be explained by genetics.
He said: "My sorrow is that on the left of politics these days, there is a great deal of running away from the sort of politics of the left in the Welsh valleys during the late 19th and early 20th century, where they didn't feel they had to be bound by poverty and fought their way out of it, partly through very high standards of education. The incentive to be a success is far higher in poor areas, which is why you frequently get individuals springing up to do very well from deprived backgrounds."
Professor Allyson Pollock, an expert on health inequalities at the Centre for International Public Health Policy, warned that linking poverty to genetics could lead to the idea that the poor were somehow inferior. "Poverty is not a genetic issue, it is an economic issue. If you go down that route you may end up with eugenics, and that is extremely worrying," she said.