Tuesday, March 31, 2009

The Red Heart Pill -- the road to immortality?

The BBC is reporting the story today of a study just published in the British medical journal, The Lancet, about the 'polypill', a 5-in-1-er that combines aspirin to prevent blood clots, a statin to lower cholesterol, and three drugs to lower blood pressure. Meant to be taken by 'everyone over 55' (a pill that everyone takes forever -- a pharmaceutical dream), the original aim was to lower heart disease by 80%.

A drug trial in India suggests that the pill has the desired effect, and is well tolerated with no downside. The reaction to this by the medical profession seems to be mixed, with many questioning the ethics of offering a pill to do what diet and exercise can already do. (Oddly, few question the ethics of these drugs taken separately, nor suggest that more money should be put into figuring out how to make health education effective.)

To us, however, a more important point is one related to a major theme of this Blog, that of causal complexity in life. The problem is known as that of competing causes, and there is nothing arcane about it. It is that if this pill actually works and becomes widely used (the BBC reports that the estimate is that incidence of heart disease and stroke will be halved, saving millions of lives), the long term effect will be to allow huge numbers of people to survive farther into old age, where they will inevitably become arthritic, mentally deficient, and will get diseases like cancers and other non-cardiovascular diseases that will be just as lethal and even more expensive, for longer, than the heart disease they didn't die of in middle age.

This is another angle on biological complexity: there is no free lunch. One can't oppose measures that increase the length of healthy life, but that doesn't mean the competing cause problem won't become a serious one. We know this clearly from what has happened in the last couple of generations as many of us have lived long enough to do complexity Blogs, once infectious diseases and other causes of early death were brought under control.

The competing cause trap also relates to what is called the 'dependency ratio', the number of people that each working-age person must support. This number is already a heavy burden, and we know that it will get dramatically worse (e.g., who will pay for Social Security for all the elders?) even without any polypills leading to yet more people to survive to become socially dependent.

Besides supporting the elderly, there will also be a problem of less resources for those here and elsewhere in the world whose needs, at young ages, are vital -- nutrition, vaccination, and so on for hundreds of millions for whom living long and hale enough to get heart disease is just a dream.

There are no easy escapes from complexity problems of this sort. Here the good of the individual competes with the good of society.The problem is what to do about it, and there the answers must come from science but also from society as a whole.

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