High fibre diets, surprisingly, may not protect gut health, but they do heighten your chances of developing diverticulosis.
The condition is characterised by small bulging pouches forming on the inner lining of large intestine, trapping bits of stool and becoming infected.
Sympoms include abdominal cramping, constipation and diarrhoea, linked with of difficulty in passing stools. More serious complications include collection of pus in the pelvis, colon obstruction and rectal bleeding.
"It looks like we may have been wrong, for decades, about why diverticula actually form," said Anne Peery, fellow in gastroenterology and hepatology, University of North Carolina's Chapel Hill School of Medicine, who led the study.
The findings, which involved more than 2,000 people, reveal that a fibrous diet actually raised the risk of developing diverticulosis, which affects about a third of adults over 60 years in the US alone, the journal Gastroenterology reports.
In fact, those with the lowest fibre intake were found to be 30 per cent less likely to develop diverticula than those with the highest fibre intake, according to a North Carolina statement.
A high-fibre diet, comprising leafy vegetables, fresh and dry fruits, grains, beans, nuts and seeds, etc., had been recommended by doctors since the late 1960s, to keep diverticulosis at bay. But this assumption has seldom been backed by studies.
The study found no links between diverticulosis and physical inactivity, intake of fat, or intake of red meat. The disease's causes remain unknown, but the researchers believe gut flora may play a role.