Protective association between dietary phytosterol intake and cardiovascular health: an analysis of the UK Biobank cohort†

Background: Cardiovascular diseases (CVDs) remain a leading cause of morbidity and mortality worldwide, with dietary interventions showing promise in reducing CVD risk factors. Phytosterols (PSs) in plant-based foods may reduce CVD risk by lowering low-density lipoprotein cholesterol. However, the relationship between dietary PS intake and CVD outcomes remains inconclusive. Methods: This study investigated the association between dietary PS intake and CVD outcomes, including coronary heart disease (CHD) and cardiovascular mortality, using a large cohort of 167 209 UK Biobank participants. PS intake was assessed through repeated 24 hour dietary recall data, with participants stratified into quintiles. The Cox proportional-hazards model was used to estimate hazard ratios (HRs) for CVD risk across quintiles of PS intake, adjusting for potential confounders. Restricted cubic splines were used to examine the nonlinear relationship between phytosterol intake and cardiovascular disease risk. Sensitivity and subgroup analyses explored interactions with demographic and lifestyle factors. Results: Higher dietary PS intake was significantly associated with a reduced risk of CVD events, including CHD and cardiovascular mortality. Each 100 mg increase in PS intake was linked to an 8% reduction in CVD risk (HR = 0.92, 95% CI: 0.87, 0.97). Multivariable-adjusted analyses revealed that participants in the highest quintile of PS intake had significantly lower CVD hazard ratios (HR = 0.81, 95% CI: 0.77, 0.84) compared to those in the lowest quintile. Significant inverse associations were also observed for cardiovascular mortality (HR: 0.86, 95% CI: 0.80, 0.94) and CHD (HR: 0.91, 95% CI: 0.84, 0.98). Subgroup analysis highlighted stronger inverse associations in current smokers, individuals with lower body mass index (BMI), and those with moderate to high physical activity levels, with variations observed based on dyslipidemia status. Sensitivity analyses, excluding early events and adjusting for energy intake, confirmed the robustness of the findings. Conclusions: This large cohort study provides evidence supporting the cardioprotective effects of dietary PS intake, particularly for CHD and cardiovascular mortality. Dietary PS may be considered an integral component of heart-healthy diets.