http://m.jamaicaobserver.com/mobile/news/Sprinting-s-Cancer-Link-
http://m.jamaicaobserver.com/mobile/news/Sprinting-s-Cancer-Link-
Sprinting’s Cancer Link?
BY VERNON DAVIDSON Executive Editor, Publications davidsonv@jamaicaobserver.com
Monday, February 20, 2012
A local urologist has suggested a possible link between sprinting prowess and prostate cancer, arguing that both have multiple causative factors that exist in the descendants of Africans who survived the inhumane conditions of the transatlantic slave voyage centuries ago.
The hypothesis is advanced by Dr William Aiken, consultant urologist at the University of the West Indies, Mona, in an article published in the December 2011 edition of the prestigious journal Medical Hypotheses.
The journal, according to its publisher Elsevier, is regarded as a forum for ideas in medicine and related biomedical sciences. Elsevier describes itself on its website as “the world’s leading provider of science and health information”, serving “more than 30 million scientists, students and health and information professionals worldwide”.
In his article, Dr Aiken, who is also a lecturer in surgery and supervisor of the UWI’s urology programme, examined the possible causes of Jamaica’s outstanding sprinting prowess and postulated whether there is a link with prostate cancer.
According to Dr Aiken, persons of African descent in the Americas, who are descendants of African slaves who survived the Middle Passage experienced a population shift in favour of greater testosterone responsiveness compared to Africans living in Africa.
This, he argued, was created by the inhumane conditions under which the slaves were transported.
“The specific conditions (slaves packed tightly in the hull of the slave ship in stifling, hot, humid conditions with little convection of air and in body fluids such as urine, faeces, vomit and menstrual effluent) created a tremendous selection pressure in which many slaves succumbed. Some ship logs indicate that as many as 90 per cent of the slaves perished during the average three-month-long journey,” Aiken wrote.
“Those who survived did so not because of luck or chance but because they had specific attributes which allowed them to withstand the adverse effects of the inhumane conditions.
“It is hypothesised that the slaves who survived had greater lean muscle mass and therefore higher skin surface area to body volume ratios and were consequently able to dissipate heat more efficiently and keep relatively cool in the hull of the slave ship; those with greater haemoglobin concentrations were able to enjoy better oxygen-carrying capacity and therefore greater tissue oxygen delivery in the stifling conditions; those with thicker, hardier skin and greater sebum production were able to resist the macerating effect of lying in urine, faeces, vomit and blood for hours without getting skin infections and sores; those with thicker and more robust bones resisted bone fractures which, should they have occurred, would have meant being tossed overboard, and finally, those with the mental toughness, vitality and aggressive will to survive would have experienced a survival advantage,” Aiken argued.
These attributes, he said, are all expressions of testosterone’s influence on the human mind and body. “Among the slaves surviving the journey there would be a much higher proportion exhibiting these features than among those who originally began the transatlantic voyage because of the severe selection pressure. Those without these attributes would have more easily succumbed and died,” he said.
“Multiply this scenario many times over for a total period of four centuries and voila! A shift in the population distribution of testosterone responsiveness in favour of greater responsiveness when comparing descendants of African slaves in the New World to West Africans in Africa,” Dr Aiken added.
“This would partly explain why relatively small countries like Jamaica and Trinidad & Tobago have done better than Nigeria, the seventh largest country in the world and by far the world’s largest consumer of yams, when it comes to sprinting prowess; it would also explain the much higher incidence and mortality from prostate cancer in the Americas compared to urban West Africa.”
Aiken argued that Australia fits nicely into his hypothesis because it has the highest documented prostate cancer incidence in the world.
“Australia, by virtue of being originally a prison colony for British prisoners, historically would have been constituted by persons on the more aggressive end of the population spectrum. The Australians would have experienced a population shift in favour of testosterone responsiveness when compared to the British population of origin,” he said.
“Moreover, the long and perilous, though not as inhumane, journey from Britain to Australia would have created some selection pressure for only the very fittest to survive. I predict, partly based on the above hypothesis, that if Australia were to develop a tradition of sprinting they would do well at it, compared to their European Caucasian counterparts.”
A version of Dr Aiken’s article, written with a lay audience in mind, is published on Pages 8 & 9 of today’s Observer.