Leading article: An age of affliction

We tend to presume that as our societies grow steadily wealthier, our health will improve too; that diseases and illnesses will be wiped out as we devote more of our communal resources to medical research. So it comes as a shock when we are told that, on present projections, this is not the direction in which we are headed at all.

According to researchers from Johns Hopkins University, the number of people living with Alzheimer's disease will probably quadruple by the middle of the century. Whereas 26 million people have Alzheimer's today, some 106 million will have the condition by 2050. The greatest increase in Alzheimer's incidence is projected for Asia, which will have 62.8 million sufferers by the middle of the century. By 2050, Europe will have 16.5 million, and America 8.8 million. This is very much a global challenge.

The reason is simple: age. Alzheimer's is an affliction of the elderly. It is usually diagnosed after the age of 60. The likelihood of developing it doubles every five years after the age of 80. The irony is that as more of us live longer, thanks to our prosperity, more of us will also encounter the ravages of dementia.

We should not underestimate what this means for our way of life. Even those of us fortunate enough to avoid developing Alzheimer's personally will be affected. The costs to society will be high. Caring for sufferers will be hugely expensive. The Johns Hopkins research team estimates that 43 per cent of cases will be so advanced they will require nursing-home care. Specialised facilities in the US cost thousands of dollars a month. Those who cannot afford to buy care will have to devote great deal of their time to looking after afflicted relatives.

There are drugs that can slow the disease, and these will be invaluable in the coming decades. Postponing the onset of Alzheimer's could reduce the number of sufferers by 12 million by 2050. And the Johns Hopkins researchers stress that early diagnosis and greater awareness of the symptoms among relatives can make a difference in this respect too.

But the painful fact is that there is no cure at the moment. The only promising avenue for research lies in building replacement neural tissue from stem cells. Yet this is precisely the area of scientific research that is being held up by the objections of the Christian right in the US and Europe. Last year, President Bush used his veto on a bill to lift a ban on federal funding for new embryonic stem cell research. There have been threats to European Union funding too.

As this study emphasises, if we allow religious dogma to place restrictions on medical research, we had better be prepared for the consequences.