Concepts of Health, Illness and Disease: A Comparative Perspective Book

Excellent introduction to the ideas of evolutionary medicine

This works as a general introduction to the nascent field of evolutionary medicine. Note well the word "health" in the title. One of the central ideas in evolutionary medicine is preserving health, and in general looking at medicine from the point of view of the healthy instead of from an overweening concentration on the sick. An ounce of prevention in evolutionary medicine is worth a whole ton of cure.

Another important idea is to look, in so far as possible, to our adaptations as evolutionary beings to see what we might be doing wrong today. For example, grasses with plump seeds of carbohydrates were in short supply before the advent of agriculture about 10,000 years ago. There were wheats and ryes, wild oats and such, but their seeds were relatively small and required a lot of labor to harvest. Consequently, our ancestors on the savannahs and in the woodlands ate grain carbohydrates in small amounts. Now, of course, grains--especially rice, wheat and corn--are the staple foods everywhere in the world and we eat massive amounts of them.

Is this a problem? As Professor Boaz points out, evolutionary medicine suggests that it is. We are "carbohydrate intolerant" (Boaz uses the term "glucotoxicity," page 133) and cannot shut down our appetite for all the carbohydrates so tantalizingly available to us. They are especially enthralling when served up with salt and fats.

In the prehistory there were no supermarkets open 24-hours a day. Instead there were freezing winters and droughts that might last for months or more, sure to visit almost every human eventually. So when there was a bountifulness in the land we chowed down big time. And those of us who had the ability to put on fat could live out the times of famine better than any prehistoric runway model. And so our chubby guy- or chubby gal-genes were favored. Boaz calls this the "thrifty genotype."

However that virtue has become a fault. What to do? Boaz recommends exercise, for one thing. In the pre-history our ancestors managed to walk all the way around the world. They had no cars or easy chairs. That we can solve our fat problem by looking at the way our ancestors lived and emulate them, is the somewhat bitter pill of this book. And, by the way, this "medicine" (hard to take, as we all know) also works against heart attacks, gout and other modern diseases.

Boaz has gone to some considerable trouble to associate various "diseases" with 17 evolutionary levels of human structure and function. (There's a table on pages 19-25.) These levels are like the idea that "ontogeny recapitulates phylogeny" in that some of the levels are similar to those stages in the embryo's development from single cell through bony fish and amphibian to mammal, all the way to us. What Boaz is adding here is the idea that certain diseases are associated with each level of development. For example, emphysema is associated with the amphibian level of adaptation while viral infections go all the way back to when our ancestors were just single cells.

This scheme is useful in helping us to understand disease. It is even helpful in treatment. But Boaz's formulation is no magic pill or cure-all. For the chronic diseases that plague those of us in the developed world there is no easy cure. Boaz recognizes a "discordance" between our evolutionary selves and the modern environment that is leading to these diseases. He uses a concept he calls "adaptive normality" that can guide us away from the discordance.

This is a very readable book requiring no prior expertise. It is obvious that Boaz wanted to reach the educated lay person with his ideas. For those of you new to the idea of evolutionary medicine, this will be an exciting book. Boaz does an excellent job of teaching us is how to think from an evolutionary perspective, which is something we all need to do.

Another interesting book on this subject is Why We Get Sick: The New Science of Darwinian Medicine (1994) by Randolph M. Nesse and George C. Williams which I also recommend.

--Dennis Littrell, author of "Understanding Evolution and Ourselves"