Mediterranean Diet for Healthy Subjects

(MAP-Med Trial)

Overseen By Maitreyi Raman, MD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of British Columbia

Must not be taking: Oral antibiotics

Disqualifiers: Irritable bowel syndrome, Diabetes, Food allergies, others

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

Compensation: Varies

Number of Visits: 6

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how different diets, specifically the Mediterranean and Western diets, affect the gut microbiome—the community of bacteria in the digestive system—in healthy individuals. Researchers aim to identify which gut microbes help people benefit most from a Mediterranean diet and what changes occur in the gut when following this diet. To ensure accuracy, participants will receive all their meals and snacks. Individuals who are generally healthy, have a Body Mass Index (BMI) between 20-25, low adherence to the Mediterranean diet, and live in the Okanagan area might be suitable for this trial. As an unphased study, this trial offers a unique opportunity to contribute to groundbreaking research on diet and gut health.

Do I need to stop taking my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications.

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

Studies have shown that the Mediterranean diet is generally safe and easy for most people to follow. Research suggests that this diet can improve heart health and reduce the risk of certain diseases. For instance, one study found that people who followed a Mediterranean diet had a 23% lower risk of dying from any cause. Another study showed fewer major heart problems among those on this diet.

These studies have not reported any major safety concerns or harmful effects. The Mediterranean diet includes healthy foods like fruits, vegetables, whole grains, and healthy fats, which are usually beneficial for most people. This diet is not only safe but may also provide significant health benefits. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Mediterranean Diet because it offers a holistic approach to health by emphasizing whole foods like fruits, vegetables, whole grains, and healthy fats, which are not typically the focus of Westernized diets. Unlike standard Western diets that are often high in processed foods and saturated fats, the Mediterranean Diet is rich in antioxidants and omega-3 fatty acids, which may promote heart health and reduce inflammation. This diet's potential to improve overall well-being and prevent chronic diseases makes it a compelling alternative to traditional dietary habits.

What evidence suggests that this trial's diets could be effective for influencing the gut microbiome?

This trial will compare the effects of the Mediterranean Diet with a Westernized Diet. Studies have shown that the Mediterranean Diet is linked to many health benefits. It can lower the risk of heart disease, depression, and dementia. Research indicates that people who follow this diet often have lower cholesterol and blood pressure, which helps protect against heart problems. Overall, adhering to a Mediterranean Diet may help individuals live longer and healthier lives. ^{6 7 8 9 10}

Who Is on the Research Team?

Natasha Haskey, RD PHD

Principal Investigator

University of British Columbia

Maitreyi Raman, MSc MD FRCPC

Principal Investigator

University of Calgary

Are You a Good Fit for This Trial?

This trial is for healthy individuals interested in how diet affects their body, specifically through the gut microbiome. Participants will be provided with all meals and snacks to ensure a controlled study environment.

Inclusion Criteria

Must live in the Okanagan area

I am free from heart disease, diabetes, and high blood pressure.

Body Mass Index of 20-25

Exclusion Criteria

Individuals with any known food allergies, reported dietary intolerances of any kind, and those with eating disorders

My diet is high in Mediterranean foods.

Individuals who are intermittent fasting or refuse to follow the study protocol

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Mediterranean Diet

Participants receive three meals and two snacks per day for three weeks, adhering to the Mediterranean Diet guidelines. Compliance is monitored through daily appetite logs and weekly meetings with the Research Coordinator.

3 weeks

3 visits (in-person)

Washout Period

Participants consume their usual diet to allow their microbiome to normalize before the next intervention.

3 weeks

Westernized Diet

Participants receive three meals and two snacks per day for three weeks, following a Westernized diet plan. Compliance is monitored through daily appetite logs and weekly meetings with the Research Coordinator.

3 weeks

3 visits (in-person)

Follow-up

Participants are monitored for changes in microbiome, depression, anxiety, and quality of life after dietary interventions.

3 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Mediterranean Diet
• Westernized Diet

Trial Overview Researchers are testing whether specific microbes predict who benefits from a Mediterranean diet compared to a Westernized diet. The study provides all food and monitors changes in participants' gut microbiomes.

How Is the Trial Designed?

Group I: Mediterranean Diet Active Control 1 Intervention

During the Mediterranean Diet (MD) phase, participants will receive three meals and two snacks per day for three weeks, adhering to the MD guidelines. To monitor compliance, participants will log their daily appetite and record any uneaten food. Additionally, participants will meet with the Research Coordinator weekly to receive guidance and support throughout the nutrition intervention.

Group II: Westernized Diet Active Control 1 Intervention

During the Westernized Diet phase, participants will receive three meals and two snacks per day for three weeks, following a Westernized diet plan. To ensure compliance, participants will log their daily appetite and record any uneaten food. They will also meet with the Research Coordinator weekly for additional support and guidance.

Group III: Washout Period Active Control 1 Intervention

This will be the period between two different interventions where participants will consume their usual diet while we wait for the participants' microbes to normalize after the first intervention before beginning the next one.

Who Is Running the Clinical Trial?

University of British Columbia

Lead Sponsor

Trials

1,506

Recruited

2,528,000+

University of Calgary

Collaborator

Trials

827

Recruited

902,000+

Published Research Related to This Trial

This study will evaluate the cardiovascular and cognitive benefits of a modified Mediterranean diet that includes 2-3 servings of fresh, lean pork per week, aiming to make the diet more sustainable for Australian populations.

The trial will involve a 24-week cross-over design with at-risk men and women, measuring various health outcomes such as blood pressure, body composition, and cognitive function, which could provide important insights for preventing cardiovascular disease and dementia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Including pork in the Mediterranean diet for an Australian population: Protocol for a randomised controlled trial assessing cardiovascular risk and cognitive function. Wade, AT., Davis, CR., Dyer, KA., et al.[2019]

The German version of the Mediterranean Diet Adherence Screener (MEDAS) was validated in a study involving 68 women with BRCA1/2 mutations, showing high concordance with a full-length Food Frequency Questionnaire, indicating its reliability for assessing adherence to the Mediterranean Diet.

Participants who adhered more closely to the Mediterranean Diet, as measured by MEDAS, demonstrated significant associations with beneficial dietary biomarkers, such as higher omega-3 and lower omega-6 fatty acid levels, suggesting potential health benefits from the diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validation of the German version of the Mediterranean Diet Adherence Screener (MEDAS) questionnaire. Hebestreit, K., Yahiaoui-Doktor, M., Engel, C., et al.[2019]

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]

Adherence to the Mediterranean Diet (MD) is linked to a lower incidence of cardiovascular and cerebrovascular events, with a significant reduction in risk observed as adherence increases, particularly in northern European participants.

In a study of 3703 individuals over 36 months, those with a higher MD score (≥4) experienced fewer vascular events compared to those with lower scores (0-1), suggesting that dietary changes can effectively reduce health risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A priori-defined Mediterranean-like dietary pattern predicts cardiovascular events better in north Europe than in Mediterranean countries. Veglia, F., Baldassarre, D., de Faire, U., et al.[2023]

A Mediterranean diet supplemented with dairy foods significantly reduced systolic and diastolic blood pressure in participants at risk of cardiovascular disease, indicating improved cardiovascular health.

The MedDairy diet also led to favorable changes in cholesterol levels, including higher HDL cholesterol and lower triglycerides, suggesting it may be an effective dietary approach for managing cardiovascular risk factors.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Mediterranean diet supplemented with dairy foods improves markers of cardiovascular risk: results from the MedDairy randomized controlled trial. Wade, AT., Davis, CR., Dyer, KA., et al.[2023]

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/34423871/

The Mediterranean diet and health: a comprehensive ... In prospective studies, adherence to the MedDiet reduced mortality, especially cardiovascular mortality, hence increased longevity. In addition, ...

2. nutritionsource.hsph.harvard.edu nutritionsource.hsph.harvard.edu/healthy-weight/diet-reviews/mediterranean-diet/

Diet Review: Mediterranean Diet - The Nutrition Source It is often promoted to decrease the risk of heart disease, depression, and dementia. The traditional diets of countries bordering the Mediterranean Sea differ ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S221133552500138X

Long-term outcomes of a Mediterranean diet with or ... These findings show that older, primarily African American adults can maintain Mediterranean Diet adherence and weight loss well after the end of a lifestyle ...

4. onlinelibrary.wiley.com onlinelibrary.wiley.com/doi/10.1111/joim.13333

The Mediterranean diet and health: a comprehensive ... 4; benefits have been seen for a wide range of health outcomes including CVD mortality, CHD and stroke incidence, type 2 diabetes, metabolic ...

5. mayoclinic.org mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/mediterranean-diet/art-20047801

Mediterranean diet for heart health More-recent studies linked the Mediterranean diet with lower risk factors for heart disease, such as high cholesterol and high blood pressure.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9317652/

The Mediterranean Diet: An Update of the Clinical Trials - PMC The study showed an increase in insulin response following a Mediterranean-style diet with respect to a low-fat diet, while postprandial glucose ...

7. hsrd.research.va.gov hsrd.research.va.gov/publications/management_briefs/default.cfm?ManagementBriefsMenu=eBrief-no104&eBriefTitle=Benefits+and+Harms+of+the+Mediterranean+Diet+Compared+to+Other+Diets

Benefits and Harms of the Mediterranean Diet Compared to ... Cohort studies indicate that conformity to a Mediterranean diet pattern is associated with significant reduction in total cancer incidence, total cancer ...

8. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2819335

Mediterranean Diet Adherence and Risk of All-Cause ... In this cohort study, higher adherence to the Mediterranean diet was associated with 23% lower risk of all-cause mortality.

9. ahajournals.org ahajournals.org/doi/10.1161/CIRCRESAHA.118.313348

The Mediterranean Diet and Cardiovascular Health Better conformity with the traditional MedDiet is associated with better cardiovascular health outcomes, including clinically meaningful ...

10. nejm.org nejm.org/doi/full/10.1056/NEJMoa1800389

Primary Prevention of Cardiovascular Disease with a ... The incidence of major cardiovascular events was lower among those assigned to a Mediterranean diet supplemented with extra-virgin olive oil or nuts.