Dietary Strategies for Diverticular Disease

When I learned about diverticulitis and diverticulosis during my nursing school days, I thought these sounded less alarming compared to other gastrointestinal issues. Little did I know that those seemingly innocuous "outpouchings'' in the colon could lead to significant challenges for those affected. My experience working in the hospital introduced me to diverticulitis complications - infections, perforations, and life-altering surgeries - and opened my eyes to the reality: diverticular disease is a serious health concern.

This gastrointestinal condition affects around 50% of individuals in Western countries by the age of 60, and becomes even more prevalent with increasing age (2)(6). Despite it being the most common reason for GI-related hospital visits in the US, there are currently no proven medical treatments available (2). Partial colon resection may treat complications or be done as an elective surgery to reduce chronic pain, but there is a lack of evidence that this actually helps reduce pain or improve quality of life (9). 

While some cases of diverticular disease are asymptomatic, a significant portion of individuals experience persistent gastrointestinal symptoms, such as bloating, pain, and altered bowel movements. Worse still, about a quarter of people face urgent complications of diverticulitis, such as painful infections, hospitalizations, bowel perforations or necessary surgery (6).

Fortunately, dietary interventions can help prevent complications in diverticular disease, and have a significant impact on health outcomes for those affected. If you or your loved one has diverticular disease, this is how the research suggests you should eat.

Reducing Disease Risk: 

There’s three clear evidence-based dietary recommendations to help reduce risk of diverticular disease. These are a high-fiber, low-red meat, and anti-inflammatory diet (2)(3).

1. High-Fiber

What counts as high fiber? Most Canadians are only getting half of the recommended daily intake of 25g per day for women and 38g per day for men, so aiming for that would be a good start (8). In fact, a fiber intake of just 30g/day was found to reduce risk of developing diverticular disease by 41% (6), but we might not want to top out there. Studies show an inverse relationship between fiber consumption and diverticular disease, suggesting the greater the intake, the better (1).

I’d strongly recommend putting your food into a tracking app like Cronometer or Myfitnesspal to figure out how much fiber you’re getting and make sure you’re hitting or exceeding the recommended daily intake. If you’re not yet there, add a couple of extra grams of fiber per week, and keep working up. Your gut health will thank you!

1. Low Red-Meat

Red meat intake is associated with higher risk of diverticulitis, with the strongest evidence pointing to unprocessed red meats as opposed to processed meats (1). But please don’t interpret this as your sign to replace the red meat in your diet with processed meats (see next recommendation for why).

1. Anti-inflammatory diet

An inflammatory diet pattern is also associated with increased risk of diverticulitis (2). In this large prospective cohort study (>46,000 participants), an inflammatory diet pattern was considered one that is high in red meat, processed meat, refined grains, and sugary beverages, and low in green leafy veggies, dark yellow veggies, coffee and tea. Even when the researchers controlled for red-meat and dietary-fiber intake, they still found an association between the inflammatory diet pattern and diverticulitis development (2), emphasizing a need to focus on anti-inflammatory foods and not simply increase fiber and avoid red meat.

People with diverticular disease also show lower levels of the antioxidant vitamins A, C, and E (5), which reiterates the need for more vitamin-rich, anti-inflammatory foods (think colorful veggies, fruits, berries, nuts and seeds). In general, the more colorful a food is, the higher its antioxidant levels, so any opportunity you have to pick a more vibrant food is likely a positive step!

Symptom Control / Management:

The dietary approach for treatment mirrors that for prevention, with a strong emphasis on fiber.

• Why fiber?

Low-fiber diets cause constipation, straining, and weakness in the inner layer of the colon, which allow it to herniate (or push through) the muscle layer, forming pouches or diverticula (4). High-fiber diets help sweep debris through the colon, keeping pressure down, preventing diverticular formation, irritation and inflammation.

Diets rich in fiber also help the body rapidly eliminate toxins. This prevents harmful waste products from being reabsorbed before excretion, reducing colon inflammation.  As inflammation is a key factor in diverticulitis (2), any way we can calm inflammation in the gut is a helpful intervention.

Another amazing function of fiber is feeding our microbiome and intestinal cells. Fiber feeds beneficial gut bacteria, and they in turn produce short-chain fatty acids (SCFAs) which feed our intestinal cells. Healthy gut cells and a proliferative microbiome create a strong barrier in our intestines, preventing leaky gut and keeping inflammation at bay (6).

• Which fiber types are best?

Insoluble fiber seems to be the most protective for diverticular disease (1), and fiber from fruit and vegetables in particular has been shown to significantly reduce the overall risk of hospitalization (6). Top food sources for insoluble fiber include: whole grains, legumes, nuts and seeds, vegetables, and fruits (especially with the skins).

*Special note

The traditional understanding of diverticulitis was that obstruction from small food-bits like nuts or popcorn caused the diverticula (colon outpouchings) to get blocked off and infected (1). This led to a common belief to avoid nuts, corn, and popcorn entirely to prevent diverticular complications (1). Thankfully, that is no longer the case! There’s actually an inverse association between nut and popcorn consumption and the risk of diverticulitis (1). So, go ahead and enjoy your nuts or popcorn as they are a delicious whole-food option to increase your fiber intake. 

Acute Diverticulitis Management:

During a flare-up, a brief period of bowel rest is typically recommended (7). This looks like a couple days of consuming only clear fluids. After bowel rest, people traditionally eased into a low-fiber diet before working up to a high-fiber diet, but more recent evidence suggests that this low-fiber progression is not necessary. A 2018 systematic review of 8 different studies concludes that there’s no evidence for a low-fiber diet during uncomplicated* acute diverticulitis, and recommended to start with a high-fiber diet as soon as the acute episode has resolved (6).

*An uncomplicated episode means without obstruction, bleeding, abscess or perforation (12).

Promising Directions in Research:

Recent research points toward gut microbial imbalance and chronic inflammation as primary culprits in diverticulitis (2). Most complications of the diverticular disease are bacteria driven, and most interventions aim to change that bacteria (6). A course of antibiotics to kill off the pathogenic microbes is often the first-line treatment for diverticulosis flare-ups (4), but what receives less attention is supporting an abundance of beneficial microbes after that course.

So how do we support a healthy gut microbiome? 

• Include a high diversity of plant foods

Including a high diversity of plant foods helps support microbial health, which is crucial for diverticular disease management (6). Different plants contain different types of fiber, and just like us humans with our favorite foods, different gut microbes prefer different fiber types (11). This means that if we consume a wide variety of plant foods, we’re supporting a diversity of gut microbes -a key marker of microbiome health (10). 

So rather than eating the same rotation of meals day after day, try to branch out and try new recipes that encourage you to eat different plants. A great goal is to aim for at least 30 different unique plant-foods per week, as research shows that consuming >30 as opposed to <10 unique types of plants per week supports significantly greater microbial diversity (11).

• Prebiotics and Probiotics

Prebiotics are a specific type of fiber that resists digestion in the upper gastrointestinal tract and reaches the colon intact, (ready to feed the gut bacteria that live down around the diverticula). To feed the beneficial gut bacteria in the colon, include prebiotic-rich foods like onions, garlic, asparagus, legumes, cooked and cooled potatoes or rice, and fruit with the peels.

Probiotics may also be helpful for diverticular disease by competing with pathogenic bacteria and helping reduce abdominal symptoms (4). Several randomized controlled trials show promise in reducing frequency of constipation, diarrhea, pain, and bloating (9). However, the research is not yet conclusive, so the specific types of probiotic therapy hasn't been defined (6). 

Until clear recommendations come out, I’d recommend fermented foods like sauerkraut, kimchi, miso, kombucha, and tempeh to naturally incorporate food-based probiotics into your diet.

• Consider your Protein Source

The composition of gut bacteria can be greatly influenced by the protein sources consumed. Diets high in protein encourage the growth of bacteria that can ferment protein, potentially suppressing beneficial strains such as Bifidobacteria and Lactobacilli (3). It's crucial to highlight that proteins derived from red meat have been associated with an increased proliferation of disease-causing microbes, upsetting the inflammatory equilibrium in the gut (3). This underscores the importance of steering clear of red meat, especially for individuals with diverticular disease.

Conclusion:

Diverticular disease is a common and debilitating gastrointestinal health issue, but nutritional interventions are powerful tools for preventing and managing complications. The evidence supporting a high-fiber, low red meat, anti-inflammatory diet is clear, offering individuals significant control over their disease trajectory.

If you made it this far, I applaud your interest in dietary strategies to improve your health! If you have any questions, or if you’re looking for guidance on implementing these recommendations, feel free to reach out - I’m here for you.

To your health,

Karen

Sources:

1. Carabotti M, Falangone F, Cuomo R, Annibale B. Role of Dietary Habits in the Prevention of Diverticular Disease Complications: A Systematic Review. Nutrients. 2021; 13(4):1288. https://doi.org/10.3390/nu13041288

2. Ma W, Jovani M, Nguyen LH, Tabung FK, Song M, Liu P-H, Cao Y, Tam I, Wu K, Giovannucci EL, Strate LL, Chan AT, Association Between Inflammatory Diets, Circulating Markers of Inflammation, and Risk of Diverticulitis, Clinical Gastroenterology and Hepatology (2019), doi: https:// doi.org/10.1016/j.cgh.2019.11.011.

3. Ticinesi, A., Nouvenne, A., Corrente, V., Tana, C., Di Mario, F., & Meschi, T. (2019). Diverticular Disease: a Gut Microbiota Perspective. Journal of Gastrointestinal & Liver Diseases, 28(3).

4. Batti, B., & Mohammad, W. (2023). Bowel Diverticulosis. Retrieved Nov 23, 2023 from https://www.intechopen.com/online-first/1169764

5. Polese B, Carabotti M, Rurgo S, Ritieni C, Sarnelli G, Barbara G, Pace F, Cuomo R, Annibale B, on behalf of REMAD Group. Patients with Diverticular Disease Have Different Dietary Habits Compared to Control Subjects: Results from an Observational Italian Study. Nutrients. 2023; 15(9):2119. https://doi.org/10.3390/nu15092119

6. Marasco, G., Buttitta, F., Cremon, C., Barbaro, M. R., Stanghellini, V., & Barbara, G. (2023). The role of microbiota and its modulation in colonic diverticular disease. Neurogastroenterology & Motility, e14615.

7. https://www.gicare.com/gi-health-resources/diverticulosis-diet/#:~:text=Early%20on%2C%20a%20diet%20consisting,is%20where%20most%20people%20are.

8. https://cdhf.ca/en/recommended-daily-fibre-intake/

9. Hantouli, M. N., Droullard, D. J., Strate, L. L., Flum, D. R., Wolff, E. M., Krane, M. K., … Davidson, G. H. (2020). Optimizing medical management for diverticular disease: a systematic review and gap analysis. Seminars in Colon and Rectal Surgery, 100782. doi:10.1016/j.scrs.2020.100782

10. Valdes, A. M., Walter, J., Segal, E., & Spector, T. D. (2018). Role of the gut microbiota in nutrition and health. BMJ, k2179. doi:10.1136/bmj.k2179 

11. McDonald, D., Hyde, E., Debelius, J. W., Morton, J. T., Gonzalez, A., Ackermann, G., … Chen, Y. (2018). American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems, 3(3). doi:10.1128/msystems.00031-18 

12. Petruzziello L, Iacopini F, Bulajic M, Shah S, Costamagna G. Review article: uncomplicated diverticular disease of the colon. Aliment Pharmacol Ther. 2006 May 15;23(10):1379-91. doi: 10.1111/j.1365-2036.2006.02896.x. PMID: 16669953.