Researchers at the Toronto University, Canada, have found a significant link between the use of contraceptive pills and the number of new cases of, and deaths from, prostate cancer.
They believe that oestrogen by-products excreted in the urine of pill-users may have contaminated the food chain and drinking water. The hormone is known to feed the growth of certain cancers, the BBC reported.
The latest investigation, published in 'BMJ Open' , looked at data from 2007 for individual nations and continents around the world to see if there was any link.
The researchers found a significant association between contraceptive pill use in the population as a whole with both the number of new cases of, and deaths from, prostate cancer.
This link was irrespective of the nation's wealth, suggesting it might not be down to better disease detection in more affluent countries that also tend to have higher rates of oral contraceptive use. And it was found to be the strongest in Europe. The researchers , however, found that there was no link between prostate cancer and other forms of contraception, like the coil, suggesting it is not something that is sexually transmitted or associated with intercourse itself.
David Margel and Neil Fleshner from the University of Toronto feared that contamination of the food chain with hormones originating from the pill are the likely culprit.
They stress that their work merely suggests a link and is not proof. "It must be considered hypothesis generating and thought-provoking ," they said.
The scientists said more research is needed and recommend close monitoring of environmental levels of oral contraceptive by-products or endocrine disruptive compounds (EDCs).