Media Centre – IARC News


Long-term opium use in Iran associated with higher risk of premature death


Opium use and mortality in Golestan Cohort Study: prospective cohort study of 50 000 adults in Iran
H Khademi, R Malekzadeh, A Pourshams, E Jafari, R Salahi, S Semnani, B Abaie, F Islami, S Nasseri-Moghaddam, A Etemadi, G Byrnes, C C Abnet, S M Dawsey, N E Day, P D Pharoah, P Boffetta, P Brennan, F Kamangar.
BMJ 2012; 344 doi: 10.1136/bmj.e2502

Read article at the BMJ website

Lyon, France – Long-term opium use, even at moderately low levels, is associated with increased risks of several causes of death, according to a study of more than 50 000 adults in Iran, published today in the British Medical Journal (BMJ). Approximately one in six of the study participants were long-term opium users, and they experienced a near doubling in risk of premature death overall compared with never users; the risk was greater among women than men. This increased risk was present for several major causes of death, including death from circulatory disorders and cancer, and for both smoking and ingestion of opium.

In 2008, an estimated 22 million people worldwide used opium or its derivatives as illicit drugs, and these results indicate that long-term ‘recreational’ opium users might be at a substantially increased risk of premature death.

“The strength of this study is that it was conducted in a population where long-term opium use at relatively low levels is common”, commented Dr Paul Brennan, from the International Agency for Research on Cancer. “By following up this population and determining who died, we were able to provide strong support that long-term recreational use of opium even in relatively low doses is harmful for many different diseases”.

This prospective cohort study, the largest of its kind ever conducted in the Eastern Mediterranean, was initially established to investigate the causes of oesophageal cancer in north-eastern Iran, where the incidence of this cancer is extremely high. The results are from the Golestan Cohort Study, a collaboration between the Digestive Disease Research Centre (DDRC, Tehran, Iran), the International Agency for Research on Cancer (IARC, Lyon, France) and the US National Cancer Institute (NCI), with additional funding from Cancer Research UK (CRUK). The study group recruited 50 000 individuals, aged 40-75 years, in Golestan Province in the north-east of Iran between 2004 and 2008. For this analysis, participants were followed until 2011.

Dr Hooman Khademi, the lead author of the current study, commented on the results: “Several experimental animal studies and a number of retrospective case-control studies had previously suggested detrimental health effects of exogenous opioids, such as morphine, but the present study is the first large-scale prospective study that corroborates those hazardous effects in humans.” This study however only covers so-called recreational use of opium, by smoking or ingestion, and no inference can be drawn from it on potential deleterious effects of therapeutic or palliative use of opioid derivatives in management of chronic disease – including cancer pain.