New York (Reuters): A new study suggests that men who eat lots of red meat are much more likely to have bowel problems, pain and nausea than their peers who stick mainly with chicken or fish.

Researchers examined more than two decades of data on more than 46,000 men and found frequent red meat eaters were 58 percent more likely to be diagnosed with diverticulitis, a common bowel condition that occurs when small pockets or bulges lining the intestines become inflamed.

“Previous studies have shown that a high-fiber diet is associated with a lower risk of diverticulitis, however, the role of other dietary factors in influencing the risk of diverticulitis was not well studied,” said senior study author Andrew Chan, a researcher at Harvard University and Massachusetts General Hospital in Boston.

“Our result shows that diets high in red meat may be associated with a higher risk of diverticulitis,” Chan added by email. Diverticulitis is common, resulting in more than 200,000 hospitalisations a year in the US at a cost of more than $2 billion, Chan and colleagues note in the journal Gut.

New cases are on the rise, and the exact causes are unknown, although the condition has been linked to smoking, obesity and the use of certain nonprescription painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs).

While diverticulitis can often be treated with a liquid or low-fiber diet, severe cases may require hospitalisation and surgery to fix complications like perforations in the gut wall.

Researchers examined data collected on men who were aged 40 to 75 when they joined the study between 1986 and 2012. Every four years men were asked how often, on average, they ate red meat, poultry and fish over the preceding year. They were given nine options, ranging from ‘never’ or ‘less than once a month,’ to ‘six or more times a day.’ During the study period, 764 men developed diverticulitis.

Men who ate the reddest meat were also more likely to smoke, more likely to regularly take NSAIDs, and less likely to eat foods with fibre or get intense exercise.

By contrast, men who ate more chicken and fish were less likely to smoke or take NSAIDs and more likely to get vigorous exercise. After accounting for these other factors that can influence the risk of diverticulitis, red meat was still associated with higher odds of developing the bowel disorder. Each daily serving of red meat was associated with an 18 percent increased risk, the study found.

Unprocessed meats like beef, pork and lamb were associated with a greater risk than processed meats like bacon or sausage. It’s possible the higher cooking temperatures typically used to prepare unprocessed meats may influence the composition of bacteria in the gut or inflammatory activity, though the exact reason for the increased risk tied to these foods is unknown, the researchers note.