Diet and Fibre: A Wind of Change

The theory that diverticular disease (DD) was caused by insufficient fibre in the diet was proposed about 40 years ago. Many websites, books and health professional reviews still persist in the recommendation that dietary fibre levels should be increased up to 30g or more per day (1,2). Some still suggest the use of added wheat bran which was found to cause problems some time ago. A wind of change is blowing through DD from a new generation of researchers and editors not afraid to point out the lack of evidence and shortcomings of the fibre theory. For example, Peery et al. (3) found that a high fibre diet with increased frequency of bowel movement was associated with a greater prevalence of diverticulosis. Low levels of dietary fibre do not cause DD (4) and increased fibre levels do not prevent diverticulitis (5).

Extra fibre merely adds to the problem if bowel motions are loose or urgent. If for any reason a sluggish bowel cannot readily respond to increased bulky faeces, then more fibre does not help. Fibre produces gas in the bowel which can cause flatulence and pain. Depending on existing levels, slowly increasing fibre in the diet may help relieve constipation and straining, while others need to reduce the amount in their diet if for example diverticulitis or urgency are problems (6). The decision is based on what makes an individual comfortable.

Medical headlines were made some time ago that people with DD can eat nuts and popcorn, when in the past avoidance was recommended. The research (7) was based on men eating nuts and popcorn twice weekly (compared with less than once a month) having reduced risk of diverticulitis. Is this a “chicken and egg” situation? The statistical study did not include an effect on pain without infection. Again people must decide for themselves if hard foods and seeds are acceptable, it may well depend on the extent of their disease and the number of diverticula. The use of soups, pureed fruit and vegetables, juices, smoothies etc. are alternative ways to get the nutrients from such foodstuffs for a varied diet. Smith (6) noted that green vegetables worsen pain in some people. Cabbage, sprouts and their like increase bowel gas and can give pain. Peas and beans have a similar effect.

Constipation is a common cause of bowel pain with DD, particularly in older people. Increasing the bulk of faeces with indigestible “insoluble” fibre from fruit, vegetables or bran does not always help, but reducing portions or using wholegrain cereal products, such as porridge, may be more acceptable. Fibre in the diet not only increases bulk of faeces but also keeps them soft. Many people find relief from pain and straining by using “soluble” gel type of fibre products containing ispaghula, methyl cellulose or sterculia. Some laxatives such as lactulose also hold water in the faeces to keep them soft. It is important to keep up a good fluid intake with such treatments or they can have the opposite effect.

People with DD must become diet detectives. “One size fits all” does not apply because of the wide variation in the way DD affects individuals. There is no foodstuff or diet which could be recommended to be beneficial for DD. Suggested recipes are often the “healthy eating” variety which can be used by anybody but their high fibre levels may not be suitable for everyone with DD. Only an individual can judge what foods will produce or reduce symptoms. Items such as fat, fruit sugars or irritants can have effects as well as fibre levels Lifestyle factors such as exercise or medication for other complaints can make a difference. Increasing numbers of researchers conclude that high levels of dietary fibre do not prevent diverticulosis or diverticulitis but levels can be used to make people with DD more comfortable. It may be useful to think of DD as a permanent condition (which it is) with remissions and regressions and use a diary to uncover possible reasons for the changes. It is important that people have a varied diet and enjoy what they eat.

© Mary Griffiths PhD 2012


1 Wick JY. Diverticular disease: eat your fibre! Consult Pharm. 2012, 27, 613.

2 Tarleton S. et al. Low-residue diet in diverticular disease: putting an end to the myth. Nutr Clin Pract. 2011, 26, 137.

3 Peery AF et al. A high-fibre diet does not protect against asymptomatic diverticulosis. Gastroenterol. 2012, 142, 266.

4 Strate LL. Diverticulosis and dietary fibre: rethinking the relationship. Gastroenterology. 2012, 142, 205.

5 Maconi G. et al. Treatment of diverticular disease of the colon and prevention of acute diverticulitis: a systematic review. Dis Colon Rectum. 2011, 54, 1326.

6 Smith J. et al. Should we treat uncomplicated symptomatic diverticular disease with fibre? BMJ. 2011, 342, d2951.

7 Strate LL. et al. Nut, corn and popcorn consumption and the incidence of diverticular disease. JAMA. 2008, 300, 907.

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