Adherence to the Mediterranean Diet and Dietary Potassium Intake: A Narrative Review of Epidemiological Evidence

The Mediterranean dietary pattern (MDP) is recognised as one of the most evidence-based dietary models for the prevention of non-communicable diseases (NCDs). Its plant-rich composition suggests an inherently high potassium intake, yet epidemiological findings on the association between MDP adherence and potassium intake remain heterogeneous. The present review aims to summarise and critically evaluate the available evidence on the association between adherence to the MDP and dietary potassium intake in the adult population.

We conducted a narrative review of observational, longitudinal and interventional studies evaluating the relationship between MDP adherence and dietary potassium intake (self-reported assessment and/or 24 h urinary potassium). MEDLINE/PubMed was searched from inception to 30 October 2025, additional studies were identified by reference screening.

From a total of 263 studies retrieved, 10 eligible studies (7 cross-sectional, 1 longitudinal, 2 randomised controlled trials) from Europe, Asia and North America were synthesised. Questionnaire-based studies consistently indicated higher potassium intake with greater MDP adherence, whereas biomarker-based findings were more variable and often attenuated, particularly in studies relying on single or unvalidated 24 h urine collections and selected samples. Overall risk of bias was high for most observational studies, while randomised trials were generally rated as having some concerns.

Higher MDP adherence is generally associated with higher potassium intake, but estimates vary by how MDP adherence is defined and scored, the potassium assessment method, and population context. Current evidence remains insufficient to quantify potassium's potential contribution as a candidate mediator without formal mediation analyses and robust exposure assessment, including repeated validated 24 h urine collections. Standardised scoring, routine reporting of potassium, sodium, and the Na/K ratio, and triangulation across dietary, biomarker and intervention evidence are key priorities to strengthen inference.