Dietary Polyphenol Intake and Risk of Hypertension: An 18-y Nationwide Cohort Study in China

Background: Although increasing evidence suggests that polyphenol helps regulate blood pressure (BP), evidence from large-scale and long-term population-based studies is still lacking. Objectives: This study aimed to investigate the association between dietary polyphenol and hypertension risk in the China Health and Nutrition Survey (N = 11,056).Methods: Food intake was assessed using 3-d, 24-h dietary recalls and household weighing method; polyphenol intake was calculated by multiplying consumption of each food and its polyphenol content. Hypertension was defined as BP & GE; 140/90 mmHg, physicians' diagnosis, or taking anti-hypertension medications. HR and 95% CI were estimated using mixed-effects Cox models.Results: During 91,561 person-years of follow-up, a total of 3866 participants developed hypertension (35%). The lowest multivariable-adjusted HR (95% CI) of hypertension risk occurred in the third quartile intake, which was 0.63 (0.57, 0.70) for total polyphenol, 0.61 (0.55, 0.68) for flavonoid, 0.62 (0.56, 0.69) for phenolic acid, 0.46 (0.42, 0.51) for lignan, and 0.58 (0.52, 0.64) for stilbene, compared with the lowest quartile. The polyphenol-hypertension associations were nonlinear (all Pnonlinearity < 0.001), and different patterns were observed. U-shaped relations with hypertension were observed for total polyphenol, flavonoid, and phenolic acid, whereas L-shaped associations were observed for lignan and stilbene. Moreover, higher fiber intake strengthened the polyphenol-hypertension association, especially for lignan (P-interaction = 0.002) and stilbene (P-interaction = 0.004). Polyphenol-containing food, particularly vegetables and fruits rich in lignan and stilbene, were significantly associated with lower hypertension risk.Conclusions: This study demonstrated an inverse and nonlinear association between dietary polyphenol, especially lignan and stilbene, and hypertension risk. The findings provide implications for hypertension prevention.