ORIGINAL RESEARCH article
Front. Nutr.
Sec. Nutrition and Metabolism
Volume 12 - 2025 | doi: 10.3389/fnut.2025.1659000
This article is part of the Research TopicImpact of Plant Bioactive Compounds on Human Nutrition and HealthView all 3 articles
Association of Dietary Fiber Intake with All-Cause and Cardiovascular Mortality in U.S. Adults with Metabolic Syndrome: NHANES 1999–2018
Provisionally accepted
- The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
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Background: Low dietary fiber intake is common in the US, despite its health benefits. Individuals with metabolic syndrome (MetS), at high cardiovascular risk, may benefit significantly from higher fiber, but its link to mortality in this group is unclear. Methods: We analyzed prospective data from 10,962 US adults with MetS (NHANES 1999-2018, mean age 58.1). Baseline fiber intake (g/day) was assessed via 24-hour recalls. MetS was defined by ATP III criteria. Mortality (all-cause, CVD-specific) was tracked via the National Death Index (median follow-up 102 months). Cox models estimated hazard ratios (HRs) for mortality associated with fiber intake, adjusted for demographics, socioeconomic status, lifestyle, and comorbidities. Results: Over follow-up, 2,617 deaths occurred (887 CVD-specific). Higher fiber intake was associated with significantly lower mortality. Our analysis suggested a potential threshold effect near 21.7 g/day of fiber intake. Below this, each additional 5g fiber reduced all-cause mortality risk by 7% (HR = 0.93, 95% CI: 0.91–0.96, p < 0.0001). Comparing highest to lowest tertile intake, adjusted HRs were 0.80 (95% CI 0.72–0.89, p<0.0001) for all-cause and 0.61 (0.51–0.73, p<0.0001) for CVD mortality. Results were robust in sensitivity analyses. Conclusion: In US adults with MetS, higher dietary fiber intake was associated with significantly lower all-cause and CVD mortality. Benefits were most pronounced at lower intakes, plateauing around 22 g/day, suggesting achieving moderate fiber intake near recommendations offers substantial survival benefits in this high-risk group.
Keywords: Dietary Fiber, metabolic syndrome, Mortality, cardiovascular disease, NHANES, cohort study
Received: 03 Jul 2025; Accepted: 29 Aug 2025.
Copyright: © 2025 Guo, Li and Huang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Meiling Li, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
Yueqin Huang, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
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