New research published in The Lancet by Dr Gilaad Kaplan shows that IBD can now be considered a global disease.
"Over the past 100 years, the incidence of IBD in Western countries has climbed and then plateaued," said Kaplan, an associate professor at the Cumming School of Medicine in Canada.
"Our research shows that countries outside the Western world now appear to be in the first stage of this sequence."
"As countries in Asia, South America and the Middle East have become industrialised, IBD has emerged and its incidence is rising dramatically. At the turn of the 21st century, it became a global disease."
Population-based studies
The research, carried out in collaboration with Siew Ng at the Chinese University of Hong Kong, gathered data from all population-based studies reporting on the incidence or prevalence of IBD since 1990.
According to the paper, cohort studies from Asia, Africa, and South America have consistently described the rising incidence of IBD in countries outside the Western world.
But within Asia, there are considerable variations across countries and regions, which the paper attributed to varying risk factors, different database capture systems, and differing access to healthcare.
"During the past generation, newly industrialised countries have experienced greater urbanisation, with populations moving from rural areas to densely populated cities," it said.
For example, in China, variation in incidence across regions is correlated with population density.
"This correlation might explain why a nationwide study of South Korea showed stable incidence of inflammatory bowel disease, whereas a study focused on a highly populated district of Seoul showed significant increases in incidence," the study noted.
Co-ordinated solution
The research also highlighted growing rates of IBD in Taiwan, which had a 4% rise in the incidence of Crohn's disease and a 4.8% rise in the incidence of ulcerative colitis from 1998 to 2008.
"As newly industrialised countries become more westernised, we can clearly see that the incidence of IBD is also rapidly rising," said Ng.
As IBD has become a global problem, Kaplan and Ng are hopeful that a co-ordinated solution to prevent and treat IBD around the world is possible.
"Future research should focus on identifying environmental risk factors observed during the early stages of industrialisation," said Ng.
Kaplan agreed, adding: "Research into environmental intervention that helps to prevent IBD should be prioritised."
A recent study from the UK found that the vast majority of children with IBD fail to meet current guidelines for calcium and vitamin D intake, prompting calls for supplementation.
Source: The Lancet
https://doi.org/10.1016/S0140-6736(17)32448-0
"Worldwide incidence and prevalence of inflammatory bowel disease in the 21st century: a systematic review of population-based studies"
Authors: Gilaad G Kaplan, et al.