This article was originally published in the Guardian, April 9, 2001; used here with permission.

How To Live Longer

by Johnjoe McFadden

This year's Reith lecturer, Professor Tom Kirkwood, claims ageing is "neither inevitable nor necessary" and invites us to "prepare for the longevity revolution." While, as he states, we are not programmed to die, it is also true that our genes have not been designed for long life.

Most of our ancestors were hunter-gathers who led short and brutal lives before falling prey to disease, starvation, predators or competitors. Their genes evolved to inhabit bodies for just a couple of decades before being passed on to their offspring.

The fate of the bodies left behind was of little concern to genes that had already fled into the next generation. Defects that showed up only in later years, leading to cancer, heart disease, Alzheimer's or stroke, would have escaped the attentions of natural selection. Long-term maintenance and repair was never a priority.

Our genes haven't changed. They are still designed for the short term, no matter how carefully we maintain and service our bodies. Ageing is a genetic disease. To cure it, we will need to turn short-term genes into long-term genes and this will be accomplished only by genetic engineering and gene therapy.

Ever since the first microbe crawled out of the primordial soup, Mother Nature has operated a strict policy of breeding from only the fit and healthy. The vast majority of creatures born into this world have departed from it without leaving any descendants. For many it might have been just bad luck, but others inherited bad genes that led to illness, frailty or plain lack of sex appeal.

Darwin described this motor of evolution but lamented its "clumsy, wasteful, blundering, low and horribly cruel" action. His cousin Francis Galton and others proposed to replace human natural selection with breeding programmes to "improve the racial qualities of future generations."

This "eugenics" movement was openly racist with the aim of ensuring that the "feeble nations" give way before the "nobler varieties of mankind."

In Germany, the 1934 racial hygiene law led to the enforced sterilisation of more than 80,000 people considered "unworthy." US eugenics policies between 1907 and 1960 resulted in the enforced sterilisation of at least 60,000 individuals. Even in liberal Sweden, more than 62,000 people (mostly women) with handicaps, or considered "undesirable," were sterilised against their will.

With such a terrible history, it is perhaps not surprising that many fear the human genome will become a eugenicist's toolkit. But there is a huge difference. Whereas eugenics seeks to restrict fertility by enforced or coerced sterilisation, gene therapy seeks simply to correct gene defects that make us sick.

The aim is not to produce Galton's "highly bred human race" but to eliminate genes that cause disease, including the infirmities of old age. Just as vaccines have conquered smallpox, gene therapy may eliminate genetic diseases like cystic fibrosis and muscular dystrophy and, eventually, the most common of them all, the ageing process.

Hardly a day goes by without Prince Charles warning us of the dangers of genetic engineering. Yet the human genome has revealed that nature is the busiest genetic engineer. More that 200 of our genes appear to have been captured from bacteria and much of the rest of the genome is a junkyard filled with the corpses of retrovirus and other parasites that have been hopping in and out of our chromosomes for millennia.

Comparing our chromosomes to those of other species, we can see that in addition to inserting new genes, nature has reshuffled, duplicated and deleted large segments of our chromosomes making about one major rearrangement every million years.

So if nature is not averse to a bit of genetic tinkering, why should we be so wary? With the decline of religion, the genome seems to have emerged as the secular equivalent of the soul: genes are sacred. Yet DNA is not spiritual. DNA comes out of your cells looking like strands of slimy cotton. You can store it in the freezer, post it to your friends; you can even eat it without suffering any ethical crisis. Genes are just bits of us and gene therapy is just another form of medicine. Fixing a broken arm is not considered to interfere with God's plan so why should fixing a broken gene be any different?

Of course any technology can be abused. But anyone wishing to use the human genome to make a super-race would not know where to start. Identifying those genes whose defects cause disease is a difficult enough task; unravelling the genetic and environmental interactions that lead to complex characters like good looks, physical strength or intelligence is far harder.

It would be foolish to by-pass the potential benefits of gene therapy because of unreasonable fears of its misuse. A surgeon could stab us in the heart but we trust him not to: we don't ban scalpels from operating theatres.

If we really wish to banish genetic diseases, including the ageing process, then we must overcome our fears of dabbling in our own genome.

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