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

75 Participants Needed

Trial Summary

What is the purpose of this trial?

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 evaluate the feasibility of this dietary intervention including willingness to randomize and adherence to a Med-style dietary pattern. The investigators will employ state-of-the-art behavioral interventions in the form of electronic feedback to improve health-related behaviors and support dietary customization based on participants' budget, dietary preferences, and restrictions. The investigators will also examine plasma inflammatory biomarkers (interleukin-6, interleukin-10, and interleukin-1β) and fecal calprotectin at baseline, 6, and 12 months.

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.

What evidence supports the effectiveness of the Mediterranean Diet and fiber supplements for treating diverticulitis?

Research suggests that a high-fiber diet, which is a key part of the Mediterranean Diet, may help reduce the risk of diverticulitis and improve symptoms after an acute episode. Increasing fiber intake through diet or supplements is recommended to prevent recurrence and manage symptoms. ^{1 2 3 4 5}

Is the Mediterranean Diet safe for humans?

The Mediterranean Diet is generally considered safe and is associated with health benefits, such as reduced inflammation and improved health outcomes in various conditions. It is known for its anti-inflammatory and antioxidant properties, which contribute to its safety and health-promoting effects. ^{6 7 8 9 10}

How does the Mediterranean Diet for Diverticulitis treatment differ from other treatments?

The Mediterranean Diet for Diverticulitis treatment is unique because it emphasizes a high-fiber diet, which is conditionally recommended to prevent recurrence and improve symptoms after an acute episode, unlike other treatments that lack strong evidence for effectiveness. ^{1 4 11 12 13}

Research Team

David R Flum, MD, MPH

Principal Investigator

University of Washington

Eligibility Criteria

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

I am 18 years old or older.

I recently had an episode of diverticulitis.

Ability to provide written informed consent in English

Exclusion Criteria

I am currently being treated for an ongoing diverticulitis episode.

I am willing and able to return for tests and complete surveys.

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

Timeline

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

Treatment Details

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.

Participant Groups

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+

Findings from Research

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 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]

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]

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]

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]

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 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]

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]

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]

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]

References

1. Switzerland 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. [2018]

2. Ireland 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. [2020]

3. United States pubmed.ncbi.nlm.nih.gov

Western Dietary Pattern Increases, and Prudent Dietary Pattern Decreases, Risk of Incident Diverticulitis in a Prospective Cohort Study. [2022]

4. United States pubmed.ncbi.nlm.nih.gov

Intake of Dietary Fiber, Fruits, and Vegetables and Risk of Diverticulitis. [2020]

5. United States pubmed.ncbi.nlm.nih.gov

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

6. England pubmed.ncbi.nlm.nih.gov

Mediterranean diet and health outcomes: a systematic meta-review. [2019]

7. England pubmed.ncbi.nlm.nih.gov

Validation of the 14-item mediterranean diet adherence screener. [2023]

8. United States 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. [2019]

9. United States 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. [2021]

10. Switzerland pubmed.ncbi.nlm.nih.gov

The Mediterranean Diet: An Update of the Clinical Trials. [2022]

11. Italy pubmed.ncbi.nlm.nih.gov

Management of diverticulosis: what's new? [2017]

12. England pubmed.ncbi.nlm.nih.gov

An unrestricted diet for uncomplicated diverticulitis is safe: results of a prospective diverticulitis diet study. [2022]

13. United States pubmed.ncbi.nlm.nih.gov

Clinical inquiries: How can you help prevent a recurrence of diverticulitis? [2017]