Inflammatory bowel disease (IBD) is a family of autoimmune conditions in which chronic recurring overreaction of the immune system causes inflammation and damage to parts of the digestive tract. While it is not completely known why this condition occurs in some people and not others, there are several risk factors. One risk factor that continues to warrant investigation is why people in urban environments are more likely to get IBD.
Like the study of asthma that showed that the Amish rarely get the chronic lung disease, it’s also possible that the lack of exposure (in urban environments) to immune-boosting bacteria in early childhood could set a person up for IBD. According to a 2014 study, “Hygiene Hypothesis in Inflammatory Bowel Disease,” researchers noted that examining the lack of exposure to bacteria that develop innate immunity is an area where future work should be focused. An additional study of Environmental Risk Factors completed in 2010 also noted that childhood respiratory infections and gatroenteritis appeared to be protective against IBD. Much more research is needed to determine what infections or exposures will specifically trigger innate immunity and protect against IBD. In the meantime, it is important not to over-sanitize your environment.
One theory as to why people who live in more urbanized areas experience more IBD is the issue of "food deserts." As many as 23.5 million people in the United States live in areas called food deserts, where there are limited food options — mainly corner mini-marts and fast food restaurants. While the Crohn’s and Colitis Foundation is still studying the role of diet in the development of IBD, we do know that diets full of fresh fruits, vegetables, lean meats, and healthy fats — like the Mediterranean Diet — appear to be helpful. If you live in one of these food deserts it is wise to look into local community gardens or ways to procure fresh foods as often as possible.
Exposures in urban environments
People in more rural environments are, generally speaking, exposed to more kinds of natural bacteria than people raised in urban areas. While it is impossible to know for sure what exposures are increasing the risk of IBD, we do know that some factors like exposure to cigarette smoke, overuse of antibiotics, lack of breastfeeding, overuse of NSAIDs, and high stress levels, among other things, may be part of why urban environments see more IBD.
If you live in an urban environment, it doesn’t mean that you or your children will get IBD, but you should be aware of the added risk. You should also discuss these issues with your physician if you have a family history of IBD. Maintaining a healthy lifestyle, eating healthy foods like those in the Mediterranean Diet, limiting exposure to the overuse of antibiotics or NSAIDs, and not overly sanitizing your environment might be a good start to leveling the playing field.
Jennifer has a bachelor's degree in dietetics as well as graduate work in public health and nutrition. She has worked with families dealing with digestive disease, asthma and food allergies for the past 12 years. Jennifer also serves the Board of Directors for Pediatric Adolescent Gastroesophageal Reflux Association (PAGER).