Objective The relationship between dietary patterns and development of abdominal aortic aneurysm (AAA) is not well understood. Thus, we prospectively evaluated the association between the anti-inflammatory potential of diet and risk of AAA.

Methods The study population included the Cohort of Swedish Men (45 072 men) and the Swedish Mammography Cohort (36 633 women), aged 45–83 years at baseline. The anti-inflammatory potential of diet was estimated using Anti-inflammatory Diet Index (AIDI) based on 11 foods with anti-inflammatory potential and 5 with proinflammatory potential (maximum 16 points) that was validated againsthigh sensitivity C reactive protein (hsCRP). Cox proportional hazard regression models were used to estimate HRs and 95% CIs. During the 14.9 years of follow-up (1 217 263 person-years), 1528 AAA cases (277 (18%) ruptured, 1251 non-ruptured) were ascertained via the Swedish Inpatient Register, the National Cause of Death Register and the Register for Vascular Surgery (Swedvasc).

Results We observed an inverse association between the AIDI and AAA risk in women and men; HRs between extreme quartiles of the AIDI (≥8 vs ≤5 points) were 0.55 (95% CI 0.36 to 0.83) in women and 0.81 (95% CI 0.68 to 0.98) in men. The AIDI was inversely associated with both ruptured and non-ruptured AAA incidence; the HR of participants in the highest quartile of AIDI compared with those in the lowest quartile was 0.61 (95% CI 0.41 to 0.90) for ruptured AAA and 0.79 (95% CI 0.65 to 0.95) for non-ruptured AAA.

Conclusion Adherence to diet with a high anti-inflammatory potential was associated with a reduced AAA risk, an association that was even more pronounced for AAA rupture.