Association between dietary antioxidant intakes and female infertility: evidence from the national health and nutrition examination survey 2013-2020.

BACKGROUND

Approximately one in eight women aged 15-49 years seek medical care for infertility. Oxidative stress is a critical factor in female infertility. The Composite Dietary Antioxidant Index (CDAI) is a novel metric for assessing overall dietary antioxidant capacity. This study aimed to investigate the association between CDAI, its individual components, and infertility risk.

METHODS

A cross-sectional analysis was conducted using 2013-2020 National Health and Nutrition Examination Survey (NHANES) data. The CDAI was calculated based on dietary intake of vitamins A, C, E, zinc, selenium, and carotenoids. Weighted logistic regression models were used to assess associations between CDAI (and its components) and infertility. Restricted cubic spline (RCS) analysis was applied to evaluate potential non-linear relationships. Subgroup and sensitivity analyses were performed to test the robustness of the findings.

RESULTS

A negative association between CDAI and infertility was observed (OR = 0.95; 95%CI [0.91-0.99], P = 0.014). Stratification by CDAI quartiles showed a consistent decreasing trend in infertility risk (Q4 vs. Q1: OR = 0.52; 95%CI [0.33-0.84], P for trend = 0.003). RCS analysis indicated a linear negative relationship between CDAI and infertility (P for non-linear = 0.278). Higher carotenoid intake was inversely associated with infertility risk, whereas intakes of vitamin A and C showed V-shaped, non-linear associations with infertility (P for non-linear < 0.05). These findings remained stable across subgroup and sensitivity analyses.

CONCLUSION

CDAI is linearly and inversely associated with the prevalence of female infertility, highlighting the potential importance of antioxidant-rich diets in promoting women's reproductive health.