When small pouches (diverticula) herniate through the colonic and muscularis mucosa of the intestine, you have a condition known as diverticulosis. Most people with diverticulosis do not have symptoms. However, if the diverticula become inflamed or infected, it becomes a complication of diverticulosis known as diverticulitis. The main symptom of diverticulitis is lower left quadrant abdominal pain. Other symptoms of diverticulitis could be fever, nausea, vomiting, chills, cramping, and constipation. (Medlineplus) Severe cases of diverticulitis must be treated with antibiotics or even surgery. To manage diverticular disease and prevent diverticulitis flare ups, research has been done in the area of how diet can help to control diverticulitis.

Causes of diverticular disease

The exact cause of diverticulosis is unknown, but there have been many factors associated with an increased risk of developing this condition, including:

  • Older age
  • Smoking
  • Obesity
  • Prescription medications (opiates, steroids, NSAIDs)
  • Lack of regular aerobic exercise

How is diet related to diverticulitis?

The type of diet you eat, among other risk factors, can increase your risk of developing this bothersome gastrointestinal disease. Epidemiologists concur that the formation of diverticula is related to a deficiency in dietary fiber intake. (Journal of Clinical Gastroenterology, 2008)

Eating high fiber foods along with proper hydration aid in keeping your stool soft, allowing it to pass more easily. However, if your diet lacks the proper amount of fiber, stools can become hard, leading to constipation. When constipation occurs, more force is required to pass the stools. It is believed that the increased pressure in the colon required to pass the stool can lead to the formation of diverticula. As stated above, diverticulitis occurs when the diverticula become infected or inflamed due to fecal matter becoming lodged in the pouches. (Healthline)

Diets high in fatty foods and red meat have also been shown to increase the risk of diverticular disease. A prospective study of diet and the risk of symptomatic diverticular disease in men examined a cohort of 47,888 US men. Along with demonstrating the inverse relationship of a high-fiber diet and diverticular disease, the study results also provided evidence that the combination of high intake of total fat or red meat and a diet low in total dietary fiber increases the risk of developing this gastrointestinal disease. (The American Journal of Clinical Nutrition, 1994)

It was previously recommended that foods such as nuts, seeds, and popcorn should be avoided in diverticular disease because it was thought that these foods could potentially get caught in the diverticula, leading to inflammation and possibly infection. According to the National Digestive Diseases Information Clearinghouse, however, there is no scientific evidence to back up this recommendation so it is not necessary to avoid these types of foods. (Livestrong)

Which foods can help control diverticulitis?

A diet high in fiber-rich foods can help to control symptoms of diverticular disease. It is important to note that there are two types of fiber, soluble and insoluble, which play different roles in helping to control diverticulitis.

Soluble fiber is able to dissolve in water and form a gel-like material that softens stools, allowing them to easily pass through the intestine. Examples of foods that contain soluble fiber are oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. (Everyday Health)

On the other hand, insoluble fiber absorbs water and adds bulk to stools, which helps to move them through the intestine easier. Insoluble fiber can be found in foods such as wheat bran, vegetables, and whole grains. (Medline Plus) Evidence indicates that diets high in the insoluble component of fiber are strongly correlated with lower risk of diverticular disease, with a particularly strong association with cellulose. (CFP)

The American Heart Association recommends obtaining fiber from food, rather than supplements, with a total daily intake of 25 grams of fiber based on a 2,000 calorie diet. The American Heart Association does not specify whether the fiber should be obtained from foods containing soluble or insoluble fiber. Interestingly, the average male and female consume approximately 50% and 62%, respectively, of the recommended level. (todaysdietitian.com)

However, after an acute diverticulitis attack, the recommended medical nutrition therapy consists of instructing the patient to first follow a low-fiber diet (10 to 15 grams per day) for a short period of time to allow the bowel to rest. Once the attack has subsided, it is recommended to gradually increase fiber intake to reach the recommended daily amount. (todaysdietitian.com)

In summary

The abdominal pain, cramping, and other gastrointestinal manifestations of diverticular disease can potentially be prevented by eating a diet that is high in fiber. A high fiber diet will reduce the incidence of constipation, reducing pressure inside the colon and reducing the formation of diverticula.