More fruit and cereal fibre tied to less risk of common bowel disease

Women who get more fibre from fruits and cereals may be less like to develop diverticulitis, a common and painful bowel problem, though vegetable sources of fibre don’t make much difference, a US study suggests. 

A low fibre diet has long been linked to an increased risk of diverticulitis, which occurs when small pockets or bulges lining the intestines become inflamed. But research to date hasn’t offered a clear picture of whether some forms of fibre might be better than others for minimising the risk, researchers note in the American Journal of Gastroenterology. 

For the current study, researchers followed 50,019 women who were 43 to 70 years old at the outset, and didn’t have a history of diverticulitis, cancer or inflammatory bowel disease. Over 24 years, 4,343 women developed diverticulitis. 

Compared to those with the lowest amounts of fibre in their diet — around 13 grammes a day — women who consumed the most fibre — closer to 27 grammes a day — were 14 per cent less likely to develop diverticulitis. 

“People concerned about developing diverticulitis, particularly those with a history of the disease [who] are worried about another episode, might want to consider increasing their intake of fibre, particularly from fruits,” said Dr Andrew Chan, senior author of the study and a researcher at Harvard Medical School and Massachusetts General Hospital in Boston. 

Women who consumed the most fruit fibre — around 1.7 grammes a day — were 17 per cent less likely to develop the condition than their counterparts who ate the least, at around 1.4 grammes daily. 

Every additional daily serving of whole fruits and specific fruits like apples, pears and prunes was associated with a 5 per cent lower risk of diverticulitis, the study also found. Some other fruits, including bananas, peaches, plums and apricots, didn’t appear to help reduce the risk. 

Women who had the most cereal fibre each day — around 9.8 grammes — were 10 per cent less likely to develop diverticulitis than those who ate the least, at about 2.9 grammes. 

While consuming more vegetable fibre also seemed connected to a lower risk of diverticulitis, the difference between low and high amounts of this fibre in the diet was small and could have been due to chance. 

Overall, the study participants consumed an average of 18 grams of fibre a day, less than the 25 daily grammes recommended for optimal health in adult women. 

Women who did get at least 25 grammes of fibre a day were 13 per cent less likely to develop diverticulitis than women who consumed less than 18 grammes a day. 

The study wasn’t designed to prove whether or how fibre intake might directly impact whether women developed diverticulitis. 

One limitation of the study is that researchers relied on women to report their own eating habits and diverticulitis diagnosis. Another drawback is that researchers lacked data on the duration or severity of diverticulitis episodes. 

Even so, the results offer fresh evidence of the importance of dietary fibre for optimal health, Chan said. 

“When we eat fibre, our bodies, in collaboration with naturally occurring bacteria in our intestines, breaks it down into specific proteins that in turn might reduce inflammation which could predispose us to diverticulitis,” Chan said. “Fibre in our diets may also influence the natural movement or motility of our colon which affects the risk of diverticulitis.”