A 26-year-long study has just been concluded, definitively linking increased red meat consumption to a bowel condition called diverticulitis. The study analyzed data collected from 46,000 men. Every two years, they were asked to fill out a questionnaire about their complete medical history and any illnesses they may have had. Every four years, they completed a questionnaire to give researchers a sense of their diets.

The study found that men who ate six or more serving of red meat each week were 58% more likely to develop diverticulitis than men who ate just 1.2 servings per week. Diverticulitis is more common after age 40. Symptoms include abdominal pain, fever, nausea, and a change in bowel habits. Diverticulitis occurs when a person’s gut lining bulges outward from its usually position and forms a small sac. Some of the other risk factors for developing diverticulitis are thought to be smoking, taking nonsteroidal anti-inflammatory drugs, and a lack of physical activity.

Although processed meat is often implicated in health problems, this study found unprocessed red meat to be the major driver of the link between high red meat consumption and the development of diverticulitis.