Mediterranean-style diet and intracranial large artery stenosis in the Northern Manhattan Study

Objectives: Given Mediterranean-style diet (MeDi) reduces risk of cardiovascular events, we hypothesized MeDi may also be protective against intracranial large artery stenosis (ICAS), a common cause of stroke worldwide.

Methods: This cross-sectional study included stroke-free participants of the Northern Manhattan Study, a diverse population-based study of stroke risk factors. We represented MeDi continuously (range 0-8) based on enrollment food frequency questionnaires, excluding alcohol consumption. We evaluated ICAS both dichotomously at clinically relevant stenosis severities and continuously as a score (possible range 0-44), summated from stenosis severity scores of major intracranial arteries from time-of-flight magnetic resonance angiography. We used logistic or zero-inflated Poisson regression, adjusting for key confounders.

Results: Among 912 included participants (mean age 64±8 years, 59% female, 65% Hispanic, mean MeDi score 4±1.5), 5% and 8% of participants had ≥50% or ≥70% ICAS, respectively (score median [interquartile range]: 0 [0-2]). Increased MeDi score was inversely associated with ICAS, but did not reach statistical significance (≥50% stenosis odds ratio (OR) [95% confidence interval (CI)]: 0.89 [0.79-1.06]; ≥70% stenosis OR [95% CI]: 0.91 [0.74-1.13]; stenosis score β-estimate [95% CI]: -0.02 [-0.06-0.01]).

Conclusion: In this stroke-free subsample, we did not find a significant association between MeDi and ICAS. We may have been limited by statistical power.