Association of a healthy diet score with left atrial morphology and function: a cardiac MRI study in the UK biobank cohort
P Nowek, J Morze, M Zechowicz, P Cyganski, A RynkiewiczAbstract
Background
Traditionally, an enlarged left atrium (LA) is seen as a sign of persistently high left ventricular (LV) filling pressures and a forewarning of negative outcomes in heart failure. Yet, in young, healthy individuals, increased LA volumes might indicate physiological remodeling driven by volume, linked to beneficial hemodynamics, increased preload, and improved cardiovascular fitness. The effect of diet quality on LA structure in those without evident cardiovascular disease has not been thoroughly explored.
Purpose
This research seeks to explore the link between diet quality and LA volumes as measured by cardiac magnetic resonance (CMR), and to ascertain if the differences observed are indicative of pathological or adaptive remodeling relevant to early heart failure risk assessment.
Methods
A prospective cohort study was carried out with 38,285 participants from the UK Biobank, all of whom had completed their initial CMR imaging session. Participants were free from cardiovascular diseases at the start and during follow-up. A Healthy Diet Score (HDS) was created using food frequency data. LA volumes were measured using CMR and adjusted for body surface area (LAVi). The relationship between diet quality and LA maximal (LAVi_max) and minimal (LAVi_min) volumes was analyzed using multivariable regression models, accounting for relevant confounders.
Results
Better diet quality was independently linked to larger indexed LA volumes. Specifically, poorer diet quality was associated with notably smaller LA volumes, with an adjusted mean difference (AMD) of −1.6 mL/m² (95% CI −2.1 to −1.1; p < 0.0001) for LAVi_max and −0.9 mL/m² (95% CI −1.2 to −0.6; p < 0.0001) for LAVi_min. This trend suggests a reduced LA reservoir capacity rather than pathological enlargement in participants with higher dietary quality.
Conclusions
Among young individuals without heart failure, superior diet quality is linked to larger LA volumes on CMR, likely reflecting physiological, preload-related atrial remodeling rather than harmful structural changes. These results highlight the need for contextual interpretation of LA size and suggest that diet quality, along with fitness and body composition, may contribute to a beneficial hemodynamic profile. Incorporating lifestyle factors with atrial–ventricular geometry could improve early differentiation between adaptive and maladaptive remodeling in heart failure prevention strategies.