Researchers in a meta-analysis study found a correlation between increased risk for inflammatory bowel disease (IBD) and meat consumption, particularly among individuals who consumed red meat. The study, titled “Meat intake and risk of inflammatory bowel disease: A meta-analysis,” was published in The Turkish Journal of Gastroenterology.

The research team investigated the association between meat consumption and the risk of IBD. To this end, researchers performed a meta-analysis on published literature, between July 1966 to July 2015 and without any restriction on language, from Pubmed and EM-BASE databases. The search included articles on IBD, ulcerative colitis, Crohn’s disease, and meat consumption (including red meat, processed meat, and white meat). Red meat was defined as “darker-colored meat from mammals, such as cows, sheep/lambs, pigs, and horses” and white meat as “lighter-colored meat from poultry, such as chickens, and rabbits.”

In total, nine studies were included in the meta-analysis. The results suggested that consumers with a high meat intake have an increased risk for IBD, with the risk degree varying with the type of meat: red meat consumption had a slight greater risk when compared with processed meat and white meat consumption.

Several mechanisms may explain the association detected. First, it was suggested that cooking meat at high temperatures generates by-products that contain mutagenic or carcinogenic characteristics which may cause a negative impact on the digestive tract. Another possible mechanism, is that the heme iron in the red-meat can lead to the formation of N-nitroso compounds that impacts cells’ proliferation activity in the digestive system. Moreover, fat consumption from animals was also suggested to increase IBD risk, with reports showing that high meat intake correlates with ulcerative colitis incidence and relapse. The consumption of linoleic acid, a polyunsaturated omega-6 fatty acid present in meat, was also recently shown to increase IBD risk.

Despite previous studies reporting an association between processed meat (here, defined as “bacon, poultry sausage, luncheon meats [red and white meat], ham, hot dogs, etc.”) and cancer risk, no correlation was found between processed meat and IBD.

In conclusion, the results suggest that a high intake of meat is associated with an increased IBD risk; however, additional studies are required to further confirm these results.