Flavan-3-ol monomers intake is associated with osteoarthritis risk in Americans over 40 years of age: results from the National Health and Nutritional Examination Survey database.

: Osteoarthritis (OA) stands as the prevailing progressive musculoskeletal disease, serving as the primary cause of chronic pain and activity limitations among adults over 40. Flavan-3-ols, common polyphenolic compounds, are believed to harbor anti-inflammatory and anti-aging properties. This study explores the relationship between flavan-3-ol intake and osteoarthritis risk in individuals over the age of 40 in the US. : This study included 7452 participants over the age of 40 from three cycles (2007-2008, 2009-2010, and 2017-2018) of the National Health and Nutrition Examination Survey. Information on OA history was obtained home surveys. Information on flavan-3-ol monomers intake was obtained using a survey from the Food and Nutrient Database for Dietary Studies. We used a logistic regression model and restricted cubic spline to analyze the relationships between flavan-3-ol monomers and OA. Stratified analyses were also conducted in this study. : There were 1056 participants with OA and 6396 without OA. Compared to the first tertile (T1) group, the adjusted odds ratio with a 95% confidence interval (CI) of logistic regression model 2 for the flavan-3-ol T2 group was 1.296 (0.979-1.715) ( = 0.068), the OR for (-)-epigallocatechin was 1.292 (1.025-1.629) ( = 0.032), and the OR for (-)-epicatechin 3-gallate was 1.348 (1.013, 1.793) ( = 0.042). A dose-response curve indicated a non-linear association ( for non-linearity <0.05) between OA and total flavan-3-ol monomers (nadir point: 483.29 mg, 95% CI: 0.61-0.90). No interaction effects were found in the subgroup analysis. : In individuals over 40 in the US, the average daily dietary intake of flavan-3-ol monomers manifests a J-shaped relationship with OA risk.