Effects of dark chocolate on kidney function

Study of the Renal Physiological Response After Chocolate Consumption

Not applicable Interventional Centre Hospitalier Universitaire Vaudois · NCT05755217

This study is testing whether eating dark chocolate can improve kidney function and blood pressure in both healthy people and those with chronic kidney disease.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment32 (estimated)
Ages18 Years and up
SexAll
SponsorCentre Hospitalier Universitaire Vaudois Academic / other
Locations2 sites (Lausanne, Canton of Vaud and 1 other locations)
Trial IDNCT05755217 on ClinicalTrials.gov

What this trial studies

This study investigates the impact of dark chocolate consumption on renal perfusion and blood pressure in both healthy volunteers and patients with chronic kidney disease. Participants will consume a single dose of dark chocolate, and their renal resistive index will be measured using Doppler ultrasound before and two hours after consumption. Continuous monitoring of blood pressure and heart rate will also be conducted during the examination. The goal is to understand the physiological effects of dark chocolate on kidney function, which have not been thoroughly explored in previous research.

Who should consider this trial

Good fit: Ideal candidates include healthy adults and patients aged 18 and older with chronic kidney disease stages 1-3.

Not a fit: Patients with severe kidney impairment (eGFR < 30 ml/min/1.73m2) or those with certain health conditions like diabetes or lactose intolerance may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into dietary recommendations for improving kidney health.

How similar studies have performed: Previous studies have shown promising results regarding the cardiovascular benefits of dark chocolate, but this specific investigation into renal effects is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria for healthy volunteers:

* Age ≥ 18 years old
* ability to understand the study protocol and to sign an informed consent.

Inclusion criteria for CKD patients:

* Age ≥18 years old,
* CKD stage 1-3,
* ability to understand the study protocol and to sign an informed consent

Exclusion Criteria:

* Lactose or cocoa intolerance,
* Diabetes,
* any severe digestive issue and liver disease,
* history of kidney stones,
* inability to follow the procedures of the study, e.g. due to language problems, dementia, etc.
* pregnant women
* healthy volunteers taking antihypertensive medication
* healthy volunteers having a known kidney malformation or abnormality
* healthy volunteers with albuminuria and/or hematuria in the urine sample.
* CKD patients with an eGFR\<30ml/min/1.73m2
* CKD patients with measured kalemia of \> 5.5mmol/l in the last three months.

Where this trial is running

Lausanne, Canton of Vaud and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Chocolate Consumptionchronic kidney diseasedoppler ultrasoundrenal resistive indexhandgrip testdark chocolatewhite chocolatecocoa
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.