Development of a comprehensive food phenolic acids database and its application: associations between dietary...

Epidemiological studies have shown that consumption of plant-based foods is associated with reduced risk of atherosclerotic cardiovascular disease. This protective effect is partially attributed to their unique phenolic acid compositions. However, previous studies have substantially underestimated the phenolic acid contents in plant foods, as conventional quantification methods primarily detect soluble free phenolic acids, while neglecting their soluble conjugated and insoluble-bound forms. This study investigated the profiles of eight phenolic acids in soluble free, soluble conjugated, and insoluble-bound forms across 322 plant foods, and further explored their associations with cardiovascular and all-cause mortality among 719 patients with coronary artery disease. The contents and ratios of phenolic acids in the three forms varied substantially across all tested food items. Salsify had the highest total phenolic acid content, 21818-fold higher than that of cucumber with the lowest level. Soluble conjugated and insoluble-bound forms predominated the phenolic acid profiles in cereals, whereas fruits were primarily rich in the soluble free form. Over a 9.33-year follow-up period, 105 cardiovascular deaths and 154 all-cause deaths were recorded. Cox proportional hazards regression analysis revealed that higher dietary intakes of total soluble free phenolic acids and gallic acid in soluble free or soluble conjugated forms were associated with increased risks of cardiovascular and all-cause mortality, whereas no significant associations were observed for total phenolic acids, or total soluble conjugated and total insoluble-bound phenolic acids. Collectively, this study provides a comprehensive food phenolic acid database, highlighting the value of distinguishing the effects of different phenolic acid forms on atherosclerotic cardiovascular disease.