The association between dietary fiber intake and osteoarthritis: a cross-sectional study from the 1999-2018 U.S. National Health and Nutrition Examination Survey.

Objective: The relationship between dietary fiber intake and osteoarthritis (OA) remains unclear. This cross-sectional study, using data from the National Health and Nutrition Examination Survey (NHANES), aimed to examine the association between dietary fiber intake and OA.

Methods: A cross-sectional analysis was conducted using NHANES data from 1999 to 2018 to assess the association between dietary fiber intake and OA. Univariate and multivariate weighted logistic regression models, along with restricted cubic spline (RCS) curves, were used to evaluate the relationship.

Results: A total of 30,620 participants were included in this study, of whom 1,864 were diagnosed with OA, yielding a prevalence of 5.74%. Multivariate weighted logistic regression revealed a consistent inverse association between dietary fiber intake and OA (OR = 0.99, 95% CI: 0.97-0.99, P = 0.018). When dietary fiber was treated as a categorical variable, the highest quartile of intake (Q4) was associated with a 27% lower risk of OA compared to the lowest quartile (Q1) (OR = 0.73, 95% CI: 0.58-0.92, P = 0.007). The RCS analysis indicated a non-linear association between dietary fiber intake and OA risk (non-linear P = 0.013). The threshold effect interval suggested that dietary fiber intake in the range of 14.4-26.7 g was associated with a reduced risk of OA, while intake above this level did not provide significant additional protection.

Conclusion: The findings demonstrate a negative linear association between dietary fiber intake and OA risk. Increasing dietary fiber consumption may reduce the risk of OA, offering potential strategies for its prevention and management. Further studies are needed to confirm these findings.