Q. I’ve read in your newsletter about the benefits of nuts and "seeded" fruits such as blueberries, but I have diverticulitis. Do I need to avoid these healthy foods because of their effects on diverticulitis?
A. Katelyn Castro, a dietetic intern at Tufts' Frances Stern Nutrition Center, and Joel Mason, MD, a gastroenterologist and professor at Tufts' Friedman School and medical school, answer: "First, it’s important to differentiate between diverticulitis and diverticulosis. Diverticulosis is a condition that occurs when small pouches (diverticula) form on the inside walls of the large intestine, bulging outwards. While most people with diverticulosis remain symptom-free, others may develop diverticulitis. Diverticulitis occurs when one or more diverticula become inflamed or infected, which may cause cramping, constipation, muscle spasms, nausea and fever. These symptoms often improve within a few days, but the recovery may require, or be facilitated by, a course of appropriate antibiotics.
"When experiencing active diverticulitis, the goal of treatment is to allow the large intestine to rest and heal. For severe attacks, a liquid diet is recommended, including broth, fruit juices, yogurt, fruit purée and pudding. For mild flareups, a low-fiber diet (10-15 grams per day) is recommended, including seedless fruits and vegetables, dairy, low-fiber cereals, tender meat, and refined pasta, bread or rice. Specifically when recovering from active diverticulitis, avoiding nuts, seeds and popcorn is recommended to help prevent further obstruction in the fecal stream.
"Once symptoms improve, you should slowly add fiber back into your diet. Current studies have found that a high-fiber diet (25 grams per day for women, 38 grams per day for men) can reduce development of further diverticuli for individuals with diverticulitis. Fiber may help to keep stools soft, allowing it to pass more easily and prevent buildup of pressure in the large intestine.
"While it seems logical to continue to avoid nuts and seeds even after recovering from diverticulitis, research to date does not support this recommendation. If you still prefer to avoid nuts and seeds, there are many other foods that can contribute to a healthy, high-fiber diet. Whole grains, beans, seedless fruits (apples, pears, melon), seedless vegetables (squash, bell peppers, spinach), and smooth nut and seed products (almond butter, peanut oil, flaxseed oil) are a few healthy and gut-friendly options for individuals with diverticulitis."