Variety and Quantity of Dietary Insoluble Fiber Intake from Different Sources and Risk of New-onset Hypertension

Background: The relations of the variety and quantity of different sources of dietary insoluble fibers and hypertension remain uncertain. We aimed to investigate the associations between the variety and quantity of insoluble fibers intake from six major food sources and new-onset hypertension, using data from the China Health and Nutrition Survey (CHNS).

Methods: Twelve thousand one hundred thirty-one participants without hypertension at baseline from CHNS were included. Dietary intake was measured by three consecutive 24-h dietary recalls combined with a household food inventory. The variety score of insoluble fiber sources was defined as the number of insoluble fiber sources consumed at the appropriate level, accounting for both types and quantities of insoluble fibers. The study outcome was new-onset hypertension, defined as blood pressure ≥ 140/90 mmHg, or physician-diagnosed hypertension or receiving antihypertensive treatments during the follow-up.

Results: During a median follow-up of 6.1 years, 4252 participants developed hypertension. There were L-shaped associations of dietary insoluble fibers derived from vegetables, beans, tubers, and fruits with new-onset hypertension; a reversed J-shaped association of whole grain-derived insoluble fiber with new-onset hypertension; and no obvious association of refined grain-derived insoluble fiber with new-onset hypertension. Therefore, refined grain was not included in the insoluble fiber variety score calculation. More importantly, a higher insoluble fiber variety score was significantly associated with lower risks of new-onset hypertension (per score increment, hazard ratio, 0.50; 95% CI, 0.45-0.55).

Conclusions: There was an inverse association between the variety of insoluble fibers with appropriate quantity from different food sources and new-onset hypertension.