A higher composite dietary antioxidant index (CDAI) is independently associated with a lower prevalence of peripheral artery disease in United States adults.
Key Findings
Results
A significant inverse association between CDAI and PAD prevalence was observed after comprehensive covariate adjustment.
Odds ratio (OR) = 0.96, 95% confidence interval (CI): 0.92–1.00 per unit increase in CDAI
The study included 6018 individuals drawn from NHANES 1999–2004
PAD prevalence in the sample was 5.9% (n = 358)
Association was examined using logistic regression, smoothed curve fitting, and interaction analyses
Covariates adjusted for included age, sex, race, education, marital status, income-to-poverty ratio, physical activity, BMI, smoking status, total cholesterol, CRP, glycosylated hemoglobin, and histories of cardiovascular disease, hypertension, and diabetes
Results
Participants in the middle CDAI tertile showed significantly lower odds of PAD compared to those in the lowest tertile.
OR for T2 vs T1 = 0.74 (95% CI: 0.56–0.98), which was statistically significant
OR for T3 vs T1 = 0.93 (95% CI: 0.69–1.24), which was not statistically significant
The non-linear pattern suggests a potential plateau effect at higher CDAI levels
CDAI was analyzed as tertiles (T1, T2, T3) to capture non-linear dose-response relationships
Results
Subgroup analyses consistently demonstrated an inverse trend between CDAI and PAD with no significant interaction effects detected.
All P values for interaction were greater than .05 across subgroup analyses
Subgroup analyses were conducted across participant demographics and health-related factors
The consistency of the inverse trend across subgroups supports the robustness of the main finding
No subgroup was identified in which higher CDAI was associated with increased PAD risk
Methods
The study was a cross-sectional analysis utilizing data from the National Health and Nutrition Examination Survey (NHANES) 1999–2004.
Total sample size was 6,018 individuals
PAD prevalence was 5.9% (n = 358)
CDAI is a composite measure of dietary antioxidant intake
Data collection included both demographic factors (age, sex, race, education, marital status, income-to-poverty ratio) and health-related factors (physical activity, BMI, smoking, cholesterol, CRP, HbA1c, and disease histories)
What This Means
This research suggests that people who consume a diet higher in antioxidants — as measured by a scoring tool called the Composite Dietary Antioxidant Index (CDAI) — are less likely to have peripheral artery disease (PAD), a condition where narrowed arteries reduce blood flow to the limbs. Using data from nearly 6,000 U.S. adults surveyed between 1999 and 2004, the researchers found that a higher CDAI score was associated with about a 4% lower likelihood of having PAD for each unit increase in the score, even after accounting for many other factors like age, smoking, diabetes, and heart disease history. People with mid-range antioxidant scores had 26% lower odds of PAD compared to those with the lowest scores.
Interestingly, the association was strongest in the middle range of antioxidant intake rather than increasing steadily — those with the highest antioxidant scores did show lower odds of PAD compared to the lowest group, but this difference was not statistically significant. The findings were consistent across different demographic and health subgroups, suggesting the relationship is broadly applicable rather than limited to specific populations.
This research suggests that dietary antioxidant intake could be a modifiable factor linked to PAD risk at a population level, though because this was a cross-sectional (snapshot-in-time) study, it cannot prove that eating more antioxidants directly prevents PAD. The authors note that future studies — particularly longer-term investigations — are needed to confirm these findings and understand the biological mechanisms that might explain why antioxidants could influence artery health.
Liu Q, Wu X, Yan J, He Y, Wang Y, Shi J. (2026). Negative association of composite dietary antioxidant index and peripheral artery disease in US participants: A cross-sectional study.. Medicine. https://doi.org/10.1097/MD.0000000000050586