It is taken as given in this day and age that people living in Europe in the Middle Ages didn’t bathe much, if at all, had no real knowledge of science or medicine, and their high mortality rates were a consequence of this general ignorance. Neither of the these assertions are, in fact, true, but the average human life span in the Middle Ages was significantly lower than the modern one nonetheless. I have discussed this in several places on this blog.
Here: https://sarahwoodbury.com/life-expectancy-in-the-middle-ages/ I discuss the life span of the royal house of Wales and the Marche. Eliminating individuals who died before adulthood completely from the equation, the mean life expectancy for women was 43.6 years, with a median of 42/43; for men, it was a mean of 48.7 and a median of 48/49. That I elminiated those who died in childhood changes the equation and it’s hard to know in all these calculations if the statistician’s numbers indicate mean (the average number), median (the middle number), and what effect including infant deaths has on the statistics.
Furthermore, here https://sarahwoodbury.com/sick-kids/ I discuss the mortality rates among King Edward I’s own family. Out of his 19 total children (3 by his second wife, Marguerite), 8 lived to grow up. However, only two lived what we would consider longish lives. Of those who actually grew up, the mean for the adult women is 41.8 with a median of 35; the mean for adult men is 36.6 with a median of 38. Combined, the mean is 39.8 and the median is 35/38. To include all children in the mortality rate brings the mean down to 18.4 and the median to a hideous 6.
What, then, were the mortality rates in the Muslim world? Muhammad promoted explorations in the sciences, including medicine. Did this increase the general lifespan of the population?
It appears not.
From my reading, not only was their little difference in lifespan across Europe, from the UK to Italy and Spain (it wasn’t cold that killed people so much as density of population that spread disease. Warfare and child birth killed people in equal measure in Italy as England–maybe more warfare in Europe, come to think on it), but into Asia as well.
This paper (http://shm.oxfordjournals.org/content/3/3/345.abstract) suggests that child mortality was equally high in the cities of the Middle East as in Europe. This is further confirmed by other sources (Daily Life in the Medieval Islamic World, by James Lindsay page 187). If child mortality was high, then death in childbirth was probably also high, and thus the average death rate of women would likely match that of the rest of the medieval world.
The long citation at Wikipedia http://en.wikipedia.org/wiki/Caliphate presents divergent views, with some texts suggesting that medieval Muslim clerics lived very long lives in comparison to the lifespan of Europeans–though some studies have shown comparable lifespans for monks/nuns in Europe, since that profession removes both childbirth and war as likely causes of death.
From that source: “The demographics of medieval Islamic society varied in some significant aspects from other agricultural societies, including a decline in birth rates as well as a change in life expectancy. Other traditional agrarian societies are estimated to have had an average life
expectancy of 20 to 25 years, while ancient Rome and medieval Europe are estimated at 20 to 30
years. Conrad I. Lawrence estimates the average lifespan in the early Islamic Caliphate to be above 35 years for the general population, and several studies on the lifespans of Islamic scholars concluded that members of this occupational group had a life expectancy between 69 and 75
years, though this longevity was not representative of the general population.
The Citations are all in Wikipedia so you can look them up. Once again, it is unclear if the authors are talking about median or mean, and to what extent ‘average’ lifespan includes children who die in childbirth or before the age of five.
http://lib.colostate.edu/research/history/medievmid.html has a nice list of books for further exploration of this issue.