Xiaohui G, Tresserra-Rimbau A, Estruch R, Martinez-Gonzalez MA, Medina-Remon A, Castañer O, et al. Effects of Polyphenol, measured by a biomarker of total polyphenols in urine, on cardiovascular risk factors After a long-term follow-up in the PREDIMED study. Oxid Med Cell Longev 2016;2572606.
Several epidemiological studies have shown an inverse association between the consumption of polyphenol-rich foods and risk of
cardiovascular diseases.However, accuracy and reliability of these studiesmay be increased using urinary total polyphenol excretion
(TPE) as a biomarker for total polyphenol intake. Our aim was to assess if antioxidant activity, measured by a Folin-Ciocalteu
assay in urine, is correlated with an improvement in cardiovascular risk factors (blood pressure and serum glucose, cholesterol,
HDL-cholesterol, LDL-cholesterol, and triglyceride concentrations) in an elderly population at high risk. A longitudinal study was
performedwith573participants (aged67.3 ± 5.9) fromthe PREDIMED study (ISRCTN35739639).We used Folin-Ciocalteumethod
to determine TPE in urine samples, assisting with solid phase extraction. Participants were categorized into three groups according
to changes in TPE. Multiple linear regression models were used to assess relationships between TPE and clinical cardiovascular
risk factors, adjusting for potential confounders. After a 5-year follow-up, significant inverse correlations were observed between
changes in TPE and plasma triglyceride concentration (𝛽 = −8.563; 𝑃 = 0.007), glucose concentration (𝛽 = −4.164; 𝑃 = 0.036),
and diastolic blood pressure (𝛽 = −1.316; 𝑃 = 0.013). Our results suggest that the consumption of more polyphenols, measured as
TPE in urine, could exert a protective effect against some cardiovascular risk factors.