Regularly eating red meat may be linked to a heightened risk of developing the common inflammatory bowel condition diverticulitis, new research suggests.
The study, from researchers at Harvard University, suggests unprocessed red met is more detrimental to health than the processed variety.
Diverticulitis occurs when the small pockets or bulges lining the intestine (diverticula) become inflamed or infected.
It is one of the most common digestive conditions, with the NHS reporting more than 113,000 hospital admissions due to diverticulitis in England in 2012 and 2013.
The researchers noted that around 4% of those affected by diverticulitis will develop severe complications, such as perforations in the gut wall, abscesses, and fistula (abnormal connections between two hollow spaces).
The team assessed the potential impact of total dietary red meat, poultry, and fish intake on the risk of developing diverticulitis in more than 46,000 men.
The men were all aged 40 to 75 when they joined the study between 1986 and 2012.
Every four years they were asked to state how often, on average, they had eaten standard size portions of red meat, poultry and fish.
They were given nine options, ranging from “never” or “less than once a month”, to “six or more times a day”.
The NHS recommends adults who consume more than 90g of red meat per day should cut down to 70g, with the average quarter pounder beef burger containing 78g of red meat.
During the 26-year monitoring period, more than 700 men involved in the study developed diverticulitis.
Those who ate higher quantities of red meat tended to use common anti-inflammatory drugs and painkillers more often, they smoked more and they were less likely to exercise vigorously. Their fibre intake was also lower.
Those who ate more poultry and fish were more likely to exercise vigorously, take aspirin and to smoke less.
But after taking account of these potentially influential factors, total red meat intake was associated with heightened diverticulitis risk.
The researchers found that those who ate the highest level of red meat had a 58% heightened risk of developing diverticulitis compared to those who consumed the lowest amount.
Each daily serving of red meat was associated with an 18% increased risk. However, risk peaked at six servings a week.
Perhaps surprisingly, the association was strongest for unprocessed red meat, and substituting one daily portion of this with fish or poultry was associated with a 20% lowered risk of diverticulitis.
The overall findings did not seem to be influenced by being overweight or by age.
Exactly how red meat intake might affect diverticulitis risk is not clear and further research is required.
The researchers noted that the higher cooking temperatures involved for unprocessed meat, which was more strongly associated with diverticulitis, may influence bacterial composition or inflammatory activity.
They added that as the research was only carried out in men, the findings may not be applicable to women.
Nevertheless, the researchers concluded: “Our findings may provide practical dietary guidance for patients at risk of diverticulitis, a common disease of huge economic and clinical burden.”