Associations between whole grains intake and new-onset hypertension: a prospective cohort study.

Importance: Epidemiological evidences regarding the association between whole grain intake and the risk of new-onset hypertension are still controversial.

Objective: We aimed to investigate the relationship between whole grain intake and new-onset hypertension and examine possible effect modifiers in the general population.

Methods: A total of 10,973 participants without hypertension from the China Health and Nutrition Survey were enrolled, with follow-up beginning in 1997 and ending in 2015. Whole grain intake was assessed by 3 consecutive 24-h dietary recalls combined with a household food inventory. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression model after adjusting for potential risk factors.

Results: During a median follow-up of 7.0 years, 3,733 participants developed new-onset hypertension. The adjusted HRs (95% CIs) were as follows: for quartile 2 (HR: 0.52; 95% CI: 0.47-0.57), quartile 3 (HR: 0.46; 95% CI: 0.42-0.51), and quartile 4 (HR: 0.35; 95% CI: 0.31-0.38), compared with quartile 1. Different types of whole grain types, including wheat (adjusted HR, 0.35; 95% CI, 0.32-0.39), maize (adjusted HR, 0.50; 95% CI, 0.42-0.59), and millet (adjusted HR, 0.38; 95% CI, 0.30-0.48), showed significant associations with a reduced risk of hypertension. The association between whole grain intake and new-onset hypertension was stronger in individuals with older age (P for interaction < 0.001) and higher BMI (P for interaction < 0.001).

Conclusion: Higher consumption of whole grains was significantly associated with a lower risk of new-onset hypertension. This study provides further evidence supporting the importance of increasing whole grain intake for hypertension prevention among Chinese adults.