The risk of developing inflammatory bowel disease is raised with high iron levels in drinking water. Inflammatory bowel disease (IBD) includes Crohn's disease and ulcerative colitis, which causes inflammation in the digestive tract. The cause of IBD is unknown, and symptoms include abdominal cramps, bloody diarrhea, fever and weight loss.Past studies have linked drinking water to IBD, but most of them focused on the content of different micro-organisms. Researchers from Norway studied the association between the content and quality of water and the incidence of IBD.
They studied 843 patients with suspected IBD and 762 of these were followed up for 5 years. They collected data about the quality of the water– levels of iron, aluminum, acidity (pH), colour, turbidity and coliform bacteria. Data regarding age, gender and degree of urbanization of the study group participants was also taken into account.It was found that iron content was significantly linked with the risk of IBD. For each 0.1 milligram per litre increase in iron, the relative risk for ulcerative colitis and Crohn’s disease increased by 23 percent and 25 percent respectively.
However, no association between IBD and aluminum content, colour, or turbidity in water was found. The age, gender and degree of urbanisation of participants had no impact on the association between iron content and the risk of disease.The researchers explained the reason for the findings by 2 mechanisms.
Firstly, high iron concentration works as a catalyst for oxidative stress, which causes inflammation and/or increases the rate of cell mutations. Secondly, iron content stimulates the growth of bacteria and increases the likelihood of inappropriate immune response in genetically predisposed individuals. Though the risk of developing inflammatory bowel disease, like ulcerative colitis and Crohn’s disease is raised with high iron content in water, further studies may be required to verify these results. - American Journal of Epidemiology November 2008