Mediterranean Diet for Diverticulitis

(IMPEDE Trial)

Overseen By Lisa Strate, MD, MPH

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Washington

Disqualifiers: Unresolved diverticulitis, Surgery, Allergy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 12 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how a Mediterranean-style diet might benefit individuals who have experienced diverticulitis, a condition where small pouches in the digestive tract become inflamed. Participants will be divided into two groups: one will follow a Mediterranean diet plan (Medi for All), while the other will adhere to standard fiber intake advice (Standard Fiber Supplementation). The trial aims to determine if these diets improve symptoms and reduce inflammation. Individuals who have recently recovered from diverticulitis may be eligible to join. As an unphased trial, this study provides participants the chance to contribute to valuable research that could enhance dietary recommendations for diverticulitis recovery.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It is best to discuss this with the trial coordinators or your doctor.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that the Mediterranean diet is generally safe and linked to health benefits like reduced inflammation and improved overall health. It is often compared to diets that help prevent diverticulitis, a condition where small pouches form in the colon and become inflamed. This way of eating is popular for its positive health effects.

Studies also indicate that consuming a lot of fiber can be beneficial. Specifically, people who consume about 30 grams of fiber each day might lower their risk of developing diverticular disease by 41%. Fiber supplements have helped some individuals avoid complications and surgeries related to diverticulitis.

Both the Mediterranean diet and fiber supplements are well-tolerated and associated with better health outcomes, making them safe options for those interested in dietary changes for diverticulitis. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these treatments for diverticulitis because they offer different approaches to managing the condition compared to standard options like antibiotics and high-fiber diets. The "Medi for All" arm introduces a Mediterranean-style diet, which is rich in fruits, vegetables, whole grains, and healthy fats, and is tailored to individuals' dietary needs and preferences. This approach not only provides a diverse range of nutrient-dense foods but also includes personalized recipes, grocery lists, and ongoing digital support to help maintain long-term dietary changes. On the other hand, the Fiber Supplementation treatment emphasizes increasing fiber intake through education and resources, aiming for at least 25 grams per day. Both treatments focus on dietary modifications as a way to potentially reduce the recurrence of diverticulitis, offering patients an alternative or complementary approach to traditional medical treatments.

What evidence suggests that this trial's treatments could be effective for diverticulitis?

This trial will compare the effects of a Mediterranean diet with fiber supplementation for managing diverticulitis. Research has shown that a Mediterranean diet, rich in fiber, might lower the risk of diverticulitis and ease its symptoms. This diet, which emphasizes fruits, vegetables, and whole grains, is linked to fewer diverticulitis flare-ups. Participants in the "Medi for All" arm will follow this diet. Meanwhile, increasing fiber intake through supplements, which participants in the "Fiber Supplementation" arm will receive, may also reduce complications and the need for surgery, although some studies have shown mixed results regarding symptom relief. Both the Mediterranean diet and fiber supplements are promising for managing diverticulitis, but the Mediterranean diet might offer additional health benefits. ^{6 7 8 9 10}

Who Is on the Research Team?

David R Flum, MD, MPH

Principal Investigator

University of Washington

Are You a Good Fit for This Trial?

This trial is for adults over 18 who have had an episode of diverticulitis in the last 18 months and can consent in English. It's not for those with allergies to Mediterranean diet foods, unable or unwilling to follow-up, currently on treatment for unresolved diverticulitis, or incarcerated.

Inclusion Criteria

Ability to provide written informed consent in English

I recently had an episode of diverticulitis.

Exclusion Criteria

I am currently being treated for an ongoing diverticulitis episode.

Currently incarcerated in a detention facility or in police custody (patients wearing a monitoring device can be enrolled) at baseline/screening

Intolerance/allergy to the main components of the Med-style food pattern

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomized to either a Mediterranean-style Food Pattern or a High Fiber Diet, with interventions including dietary education, electronic feedback, and support resources.

12 months

Bi-weekly online interactions, quarterly dietician sessions

Follow-up

Participants are monitored for safety, dietary adherence, and changes in biomarkers and quality of life.

12 months

Quarterly assessments

What Are the Treatments Tested in This Trial?

Interventions

• Medi for All
• Standard Fiber Supplementation

Trial Overview The study compares a Mediterranean-style diet (Medi) with standard fiber supplements in managing diverticulitis. Participants will be randomly assigned to one of the diets and receive electronic feedback to support dietary adherence. Inflammatory markers will be tracked over a year.

How Is the Trial Designed?

Group I: Fiber Supplementation Active Control 1 Intervention

Participants randomized to the High Fiber Diet Arm will be given commonly used patient education pamphlet,149 describing fiber and high-fiber foods, the rationale for increasing fiber intake, and ways patients can promote greater intake. Based on prior observational studies of incident diverticulitis, at least 25 grams/day of fiber will be recommended for participants.

Group II: Medi for All Active Control 1 Intervention

Participants randomized to the USDA Mediterranean-style Food Pattern Arm (called Medi for all) will have access to a "toolbox" that includes education materials (e.g., food pattern tables according to daily caloric intake), recipes, grocery lists, group-based online dietary support, feedback, and reminders to encourage dietary change. Recipes and grocery lists can be individualized to a participant's food budget and preferences. Materials will be available in print and Web-based. This state-of-the art intervention will then use electronic feedback in the form of nudge messages designed to motivate participants to sustain or improve adherence to the Med-style Food Pattern.

Who Is Running the Clinical Trial?

University of Washington

Lead Sponsor

Trials

1,858

Recruited

2,023,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

In a study of 46,295 men over 894,468 person-years, a Western dietary pattern, characterized by high intake of red meat and refined grains, was linked to a 55% increased risk of developing diverticulitis compared to a more prudent dietary pattern.

Conversely, adhering to a prudent dietary pattern, rich in fruits, vegetables, and whole grains, was associated with a 26% reduced risk of diverticulitis, highlighting the importance of dietary choices in prevention.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Western Dietary Pattern Increases, and Prudent Dietary Pattern Decreases, Risk of Incident Diverticulitis in a Prospective Cohort Study. Strate, LL., Keeley, BR., Cao, Y., et al.[2022]

The Mediterranean diet (MeDi) is associated with improved health outcomes and may help reduce the risk of non-communicable diseases (NCDs), as summarized from 33 articles including systematic reviews and meta-analyses.

Combining the MeDi with physical activity and avoiding tobacco and excessive alcohol consumption enhances its health benefits, suggesting a comprehensive approach to promoting better health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mediterranean diet and health outcomes: a systematic meta-review. Martinez-Lacoba, R., Pardo-Garcia, I., Amo-Saus, E., et al.[2019]

This systematic review of eight studies found very low-quality evidence suggesting that a liberalized diet (higher fiber) may be better than a restricted diet for managing acute, uncomplicated diverticulitis in hospitalized patients.

After recovery from an acute episode, a high dietary fiber diet is strongly recommended to help prevent recurrence and improve gastrointestinal symptoms, aligning with general dietary guidelines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evidence for Dietary Fibre Modification in the Recovery and Prevention of Reoccurrence of Acute, Uncomplicated Diverticulitis: A Systematic Literature Review. Dahl, C., Crichton, M., Jenkins, J., et al.[2018]

A systematic review of nine studies involving older adults (ages 57 to 70) found that dietary fiber supplementation significantly increased stool weight, suggesting it can improve bowel function in patients with asymptomatic or symptomatic uncomplicated diverticular disease.

However, the evidence regarding the impact of dietary fiber on gastrointestinal symptoms and stool transit time was not significant, indicating that while fiber may help with stool consistency, it may not alleviate other digestive issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Role of dietary fibre in older adults with asymptomatic (AS) or symptomatic uncomplicated diverticular disease (SUDD): Systematic review and meta-analysis. Eberhardt, F., Crichton, M., Dahl, C., et al.[2020]

In a study of 50,019 women over 24 years, higher total fiber intake was linked to a lower risk of diverticulitis, with a hazard ratio of 0.86 for those in the highest fiber intake group compared to the lowest.

Specifically, fiber from fruits and cereals (not vegetables) was associated with reduced diverticulitis risk, with each additional serving of whole fruit leading to a 5% decrease in risk.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intake of Dietary Fiber, Fruits, and Vegetables and Risk of Diverticulitis. Ma, W., Nguyen, LH., Song, M., et al.[2020]

The 14-point Mediterranean Diet Adherence Screener (MEDAS) is a valid and reliable tool for assessing adherence to the Mediterranean diet in a Turkish population, based on a study of 188 participants.

There was a strong correlation between the MEDAS scores and a 3-day food record, indicating that MEDAS can effectively estimate dietary adherence, particularly for components like olive oil and sweets, although it was less effective for fish and seafood.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validation of the 14-item mediterranean diet adherence screener. Bekar, C., Goktas, Z.[2023]

A high-fiber diet may be beneficial after recovery from acute diverticulitis, but there is no direct evidence that it prevents recurrent diverticulitis.

Contrary to common advice, consuming nuts, seeds, corn, and popcorn does not increase the risk of diverticulitis and may even offer protective benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical inquiries: How can you help prevent a recurrence of diverticulitis? Weisberger, L., Jamieson, B.[2017]

A Mediterranean diet (MedDiet) significantly reduced the dietary inflammatory index (DII) score in patients with coronary heart disease (CHD) over a 6-month period, indicating a more anti-inflammatory dietary pattern compared to a low-fat diet.

Despite the reduction in DII scores with the MedDiet, there were no significant changes in inflammatory markers like high sensitivity C-reactive protein (hs-CRP) and interleukin-6 (hs-IL-6), suggesting that further research is needed to explore the relationship between diet and inflammation in larger studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Randomization to 6-month Mediterranean diet compared with a low-fat diet leads to improvement in Dietary Inflammatory Index scores in patients with coronary heart disease: the AUSMED Heart Trial. Mayr, HL., Thomas, CJ., Tierney, AC., et al.[2019]

In a study of 183 hospitalized patients over 65 years old, adherence to the Mediterranean diet (MedDiet) was associated with a significant reduction in hospital length of stay by 0.3 days for each unit increase in MedDiet score.

Higher adherence to the MedDiet also correlated with a 13% decrease in long-term mortality risk, suggesting that this dietary pattern not only improves health outcomes but may also reduce healthcare costs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Mediterranean diet on hospital length of stay, medical expenses, and mortality in elderly, hospitalized patients: A 2-year observational study. Lampropoulos, CE., Konsta, M., Dradaki, V., et al.[2021]

The Mediterranean Diet (MedDiet) has been linked to numerous health benefits, particularly in reducing the risk of cardiovascular diseases, metabolic disorders, and cancer, as evidenced by an increase in clinical trials over the last decade.

The diet's positive effects are largely attributed to its anti-inflammatory and antioxidant properties, with strict adherence and specific components like olive oil playing crucial roles in managing obesity and waist circumference.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Mediterranean Diet: An Update of the Clinical Trials. Finicelli, M., Di Salle, A., Galderisi, U., et al.[2022]

Diverticulitis is primarily linked to a low-fiber diet, with dietary factors such as increased vegetable and fiber intake shown to reduce the risk of developing diverticular disease and diverticulitis.

While age is a significant risk factor, obesity and high red meat consumption are also associated with diverticulitis, but the progression from asymptomatic diverticular disease to diverticulitis remains poorly understood.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Diverticulitis: new frontiers for an old country: risk factors and pathogenesis. Korzenik, JR.[2008]

A study involving 86 patients with their first episode of uncomplicated diverticulitis found that following an unrestricted diet was generally safe, with complication rates consistent with existing literature.

Out of the patients, 19.8% reported ongoing symptoms after 6 months, and only 4.7% experienced a recurrence of diverticulitis, suggesting that an unrestricted diet does not significantly increase the risk of complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An unrestricted diet for uncomplicated diverticulitis is safe: results of a prospective diverticulitis diet study. Stam, MA., Draaisma, WA., van de Wall, BJ., et al.[2022]

The rising incidence of diverticulosis and diverticular disease, including acute diverticulitis, is becoming a major health concern globally, leading to increased healthcare costs.

Current treatments being explored for preventing diverticulitis recurrence include fiber, non-absorbable antibiotics, 5-aminosalicylic acid, and probiotics, but evidence supporting their effectiveness is still insufficient.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Management of diverticulosis: what's new? Elisei, W., Brandimarte, G., Tursi, A.[2017]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3308000/

A systematic review of high-fibre dietary therapy in ... Those treated with fibre supplementation fared significantly better in developing fewer complications and required less surgery (p < 0.05). At the time of ...

2. blogs.the-hospitalist.org blogs.the-hospitalist.org/content/what-most-beneficial-diet-patients-diverticulosis

What is the most beneficial diet for patients ... A small randomized trial of lactulose vs dietary fiber showed both treatments to be effective in alleviating symptoms of diverticular disease.

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5331592/

Role of Fiber in Symptomatic Uncomplicated Diverticular ... The main outcome measures were a reduction of abdominal symptoms and the prevention of acute diverticulitis. Nineteen studies were included, ...

4. journals.lww.com journals.lww.com/jcge/fulltext/2011/04001/case_presentation__the_role_of_diet_fiber.10.aspx

Case Presentation: The Role of Diet-Fiber Although fiber may decrease the chance of recurrent diverticulitis, the nature and extent of a decrease in recurrent symptoms of diverticulosis is uncertain.

5. mdpi.com mdpi.com/2072-6643/10/2/137

Evidence for Dietary Fibre Modification in the Recovery ... This review found low confidence in the evidence that high dietary fibre intake will result directly in improved risk for diverticulitis reoccurrence and/or ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT05681559

Investigation of Medical Management to Prevent Episodes ... This is a randomized trial (n=75) of a Mediterranean style Food Pattern and versus standardized guidance on fiber intake for patients with diverticulitis to ...

7. withpower.com withpower.com/trial/phase-diverticulitis-2023-f1d50

Mediterranean Diet for Diverticulitis (IMPEDE Trial) The Mediterranean Diet is generally considered safe and is associated with health benefits, such as reduced inflammation and improved health outcomes in various ...

8. gastro.uw.edu gastro.uw.edu/research/diverticular

Diverticular Disease | Division of Gastroenterology The Mediterranean diet pattern is comparable to diets associated with the primary prevention of diverticulitis, is more strongly associated with reduced ...

9. cdn.clinicaltrials.gov cdn.clinicaltrials.gov/large-docs/59/NCT05681559/Prot_SAP_001.pdf

Flum/Strate Study Protocol Version 5.0 August 7, 2023 • Participants randomized to Medi For All will participate in an introductory session regarding a USDA Healthy Med-style Food Pattern.

10. 2minutemedicine.com 2minutemedicine.com/particulate-foods-not-associated-with-incident-diverticulitis-in-women/

Particulate foods not associated with incident diverticulitis ... Overall, these results demonstrated that dietary intake of peanuts, nuts, and seeds was not associated with heightened incident diverticulitis ...