This article was first published inÂ
If you have diverticulosis, you were probably told to avoid eating nuts and seeds. The worry was that tiny food particles could get stuck in the small cervices of the bowel wall and get infected. It was inherently logical and made a lot of sense to many physicians. But it may not be true.
For clarity, a diverticulum is a sac-like outpouching of the large intestine. This tends to happen at weak points of the bowel wall where the muscle layer has thinned or weakened. People used to think diverticula were brought on by a low-fibre diet and chronic constipation, but more recent data has not borne that out. Age seems to be the most reliable risk factor, and they can be seen in nearly 60 per cent of people over age 60.
When a patient is found to have diverticula in their large intestine, usually on routine colonoscopy or imaging, then they are diagnosed with diverticulosis. Diverticulitis is when the diverticula become infected or inflamed, and it can be extremely painful. Although it was once thought that diverticulitis was common in patients with diverticulosis, more recent data suggests the opposite. Only about will develop an acute diverticulitis, and complications are generally rare.
Antibiotics are the mainstay of treatment. Occasionally, if complications develop like an abscess or a bowel obstruction, surgery is necessary. However, (Efficacy and Safety of Nonantibiotic Outpatient Treatment in Mild Acute Diverticulitis) recently found that people with mild disease will recover even without antibiotics, so the prognosis is usually very positive.
Despite the reassuring recent data, hospitalization rates and health care costs for diverticulitis are rising because of our aging population. Routine advice has always been for patients with diverticulosis to avoid seeds and nuts. It is a mainstay of medical advice and makes a certain intuitive physiologic sense. Small food particles could become trapped in the diverticula, irritate the bowel wall, become a source of infection and lead to a painful case of diverticulitis.
However, the hypothesis — though logical — has very little data to back it up. As far back as 2008, found that eating nuts, corn and popcorn did not increase the risk of diverticulosis or diverticulitis. It was a provocative report that challenged the common recommendation to avoid these foods, but it had several drawbacks. It was not a randomized trial, it included only men, and it did not control for overall dietary patterns.
sought to address these issues. Although initially designed to study women with a family history of breast cancer, the authors were able to leverage the health data of nearly 30,000 women in their database and confirm a diagnosis of diverticulitis by analyzing their health records. A healthy overall diet reduced the risk of diverticulitis, but importantly the exact nature of that diet did not matter. Several common dietary indices like the Mediterranean diet, the DASH diet (low in salt and high in fruits and vegetables), and the Health Eating Index (which measures compliance with U.S. Department of Agriculture dietary guidelines) were all associated with a reduced risk of diverticulitis. But eating nuts, seeds and corn was not.
Like the previous study in men, this was a non-randomized trial and relied on food questionnaires to assess the women’s diet. Food questionnaires are problematic because they do not always accurately reflect what people eat over the long term given the failings of human memory.
Still, two independent analyses in different patient populations have come to the same conclusion. The evidence is starting to suggest that the widespread prohibition against seeds and nuts, often recommended to patients, just isn’t justified.
Christopher Labos is a Montreal physician. He is the host of the podcast and the author of
