Crohn's disease is thought to be caused by environmental factors (diet, lifestyle, smoking) among genetically susceptible individuals. Mutations in CARD15, a gene involved in innate immunity, are known to predispose people to the disease.
Jean-Pierre Hugot from Hopital Robert Debre, Paris, France, and colleagues discuss the cold-chain hypothesis (the production and storage of food in low temperatures) as a potential major risk factor for Crohn's disease. Jean-Pierre Hugot comments: "All findings point to refrigeration as a potential risk factor for Crohn's disease. Furthermore, cold-chain development paralleled the outbreak of Crohn's disease during the 20th century. The cold chain hypothesis suggests that psychrotrophic bacteria such as Yersinia and Listeria-commonly found in beef, pork, chicken, sausages, hamburgers, cheese, and lettuce-contribute to the disease.
These bacteria have been identified in Crohn's disease lesions. From a molecular perspective, we suggest that the disease is a result of a defect in host recognition by pathogenic bacterial components that usually escape the immune response, which results in an excessive host response to these bacteria."
Contact: Dr. Jean-Pierre Hugot, Service de gastroenterologie, Hopital Robert Debre, 48 Bd Serurier, 75019 Paris, France. T33-1-40-03-20-00; E): jean-pierre.hugot@rdb.ap-hop-paris.fr .
The Lancet