Effect of Plant-based Diets on Liver Biomarkers, Cardiometabolic Health, and Exposure to Environmental Contaminants and Endocrine Disruptors in Patients With Metabolic Liver Disease.

Summary

Plant-based diets have gained increasing recognition for their sustainability and their benefits on cardiometabolic and liver health. However, evidence regarding their effects in patients with metabolic liver disease (MetLD) remains limited. The primary objective of this project is to compare the effects of a traditional Mediterranean diet and a Mediterranean diet exclusively based on plant-derived foods on liver parameters, cardiometabolic health, gut microbiota, and exposure to environmental contaminants in patients with MetLD.

This study is a randomized clinical trial with a 1:1 allocation ratio into two groups: a traditional Mediterranean diet, considered the standard diet in our setting and recommended for this condition, and a Mediterranean diet exclusively based on plant-derived foods, both designed by registered dietitians. The intervention will last 12 weeks.

Anthropometric, metabolic, hepatic, inflammatory, and quality of life variables will be assessed. Additionally, gut microbiota, genetic variants associated with MetLD, and internal exposure to environmental contaminants will be evaluated using biological samples. A 4-week follow-up after the intervention will also be conducted to assess the integration of lifestyle recommendations among participants.

The results will contribute to the development of safe, sustainable, and cost-effective nutritional strategies and may serve as a basis for future clinical guidelines integrating precision nutrition and planetary health in the management of chronic liver diseases.

The traditional Mediterranean diet has shown metabolic and hepatic benefits; however, its reformulation toward a predominantly plant-based pattern may enhance these effects by reducing saturated fat intake and increasing the consumption of fiber, bioactive compounds, and fatty acids with a more favorable profile. Moreover, this type of diet limits the intake of animal-based foods associated with the bioaccumulation of environmental contaminants such as PFAS and heavy metals, which are increasingly implicated in the progression of MetLD.

This project hypothesizes that a Mediterranean diet based exclusively on plant-derived foods, compared to a traditional Mediterranean diet, will lead to greater improvements in hepatic, metabolic, and inflammatory parameters in patients with MetLD, and will additionally be associated with a lower internal burden of bioaccumulative environmental contaminants.

Primary objective To evaluate the effect of a Mediterranean diet based exclusively on plant-derived foods on MetLD, assessed non-invasively through biochemical and elastographic parameters.

Secondary objectives To evaluate changes in metabolic parameters, anthropometric measures, and body composition.

To examine changes in systemic inflammatory markers, such as C-reactive protein and the neutrophil-to-lymphocyte ratio.

To assess exposure to environmental contaminants, specifically heavy metals (lead, cadmium, mercury) and endocrine disruptors such as perfluorinated compounds (PFAS), and their relationship with liver damage.

To evaluate whether genetic variants associated with susceptibility to and progression of MetLD modulate hepatic and metabolic responses to dietary patterns.

To analyze changes in gut microbiota following the plant-based diet and their association with liver improvement.

Conditions

• Metabolic Dysfunction-associated Liver Disease

Interventions

OTHER

Traditional Mediterranean diet

This dietary pattern is considered the standard of care in the study setting and includes a balanced intake of plant- and animal-derived foods, consistent with current clinical recommendations for metabolic liver disease. The diet emphasizes high consumption of vegetables, fruits, legumes, whole grains, nuts, seeds, and olive oil as the primary source of fat. Moderate intake of fish, poultry, eggs, and low-fat dairy products will be encouraged, while red and processed meats, added sugars, and ultra-processed foods will be limited.

OTHER

Vegan Mediterranean diet

This dietary pattern is designed and supervised by registered dietitians and emphasizes high consumption of vegetables, fruits, legumes, whole grains, nuts, seeds, and olive oil as the primary source of fat, in line with Mediterranean dietary principles. All animal-derived foods (including meat, fish, seafood, dairy products, and eggs) will be excluded. Legumes, whole grains, nuts, and seeds will serve as the main sources of protein and healthy fats. Participants will be encouraged to prioritize whole, minimally processed foods; however, plant-based alternatives to meat and dairy may be allowed in cases where necessary to support adherence.

Sponsors & Collaborators

• IMDEA Food

  collaborator OTHER

• Hospital Clinico Universitario San Cecilio

  collaborator OTHER

• Hospital Universitario Puerta del Hierro

  collaborator UNKNOWN

• Miguel López Moreno

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-04-18

Primary Completion

2026-12-19

Completion

2027-03-10

Countries

• Spain

Study Locations