A Canadian study published in British Medical Journal Open says that increasing use of the contraceptive pill is being linked with the rise of prostate cancer in men.
According to researchers, the Pill has soared in popularity over the past 40 years, and at the same time prostate cancer has become the most common form of the disease in men.
There is a statistical relationship between the two trends, possibly driven by men’s greater exposure to the oestrogen hormone contained in the Pill.
Widespread use of the Pill has led to more of the hormone finding its way into the water supply and food chain, with implications for human health, says the study in BMJ Open.
Using data from 87 countries, researchers found that where the proportion of women using the contraceptive pill is higher, rates of prostate cancer are higher.
Other contraceptives such as intrauterine devices or condoms were not linked to a higher incidence of prostate cancer.
A team of researchers from Canada used two sets of data to pinpoint rates of prostate cancer and associated deaths and the proportion of women using common methods of contraception for 2007.
Use of the contraceptive pill was significantly associated with the number of new cases of prostate cancer around the world, in findings which were not affected by a nation’s wealth and therefore probably not influenced by better detection through screening and health services.
“The research is speculative and definitive conclusions cannot be drawn,” said research leader Dr. David Margel, of the Princess Margaret Hospital, Toronto University.
Excess exposure to oestrogen is known to cause cancer and the study suggests that widespread use of the Pill has resulted in by-products called endocrine disruptors being deposited in the environment.
These do not break down easily in the body so can be passed into urine and end up in the water supply or the food chain, thus exposing the general population.
Dr. Kate Holmes, of The Prostate Cancer Charity, said: “This study does not present a strong evidence case for an association between the use of the contraceptive pill and prostate cancer, nor does it intend to.
“It is intended to explore the possibility that release of endocrine disruptive chemicals (EDCs) into the environment, a process which is not unique to the Pill, might impact on the incidence of the disease.
“However, for all of the 87 countries in the study, there is no information on the level of these chemicals in the environment, with the focus on the contraceptive pill as the sole source, which we know is not the case.”