Monday, August 19, 2013

Lewontin 1991: Scientific medicine

PS: Wiki defines Scientific medicine is a modern form of medicine stemming from the synthesis of the Flexnerian medical education reforms of the early 1900s and the Germ theory of disease.

In the Wiki sense, scientific medicine then dates to the Flexnerian reforms.


 Lewontin, Richard C., "A Reasonable Skepticism" from Biology as Ideology: The Doctrine of DNA (New York: HarperPerennial, 1991):
Yet it is remarkable how much important practical science has been quite independent of theory. In Chapter 3, I will consider one of the most famous examples of scientific agricultural change: the introduction of hybrid corn all over the world. Hybrid corn is said to be one of the great triumphs of modern genetics in action, helping to feed people and increase their well-being. Yet the development of hybrid corn and, indeed, almost all plant and animal breeding as it is actually practiced has been carried out in a way that is completely independent of any scientific theory. Indeed, a great deal of plant and animal breeding has been done in a way indistinguishable from the methods of past centuries before anyone had ever heard of genetics.

The same is true for our attempts to cope with killers like cancer and heart disease. Most cures for cancer involve either removing the growing tumor or destroying it with powerful radiation or chemicals. Virtually none of this progress in cancer therapy has occurred because of a deep understanding of the elementary processes of cell growth and development, although nearly all cancer research, above the purely clinical level, is devoted precisely to understanding the most intimate details of cell biology. Medicine remains, despite all the talk of scientific medicine, essentially an empirical process in which one does what works.
Already by 1991, the first genetically modified crops were appearing.   The number of drugs and disease treatments that have proceeded from at least some understanding of the fundamental biology involved have greatly increased.   In that sense the above is now somewhat dated.

But the reason for mentioning the quote above is that it gives a clue as to what Lewontin might mean by scientific medicine.   He seems to mean medicine based on deep understanding of the underlying biology.

For instance, as far as I know, we only know that high LDL cholesterol is correlated with heart disease, and that lowering cholesterol seems to reduce the risk of death from heart disease in many populations.  But the causal mechanisms are unclear.

Similarly, some cancer drugs are designed to attack the rapidly dividing cells of a tumor; but why the tumor cells have become that way in the first place is not clear. 

In that sense, we are still largely in the state of "essentially an empirical process in which one does what works".