Abstract MP85: Mediterranean Diet and Incidence of Stroke in the California Teachers Study

Introduction: A Mediterranean diet (MeDi) has been associated with a reduced incidence of cardiovascular and neurodegenerative diseases, and overall mortality, in several prospective studies. There is limited data, however, regarding the relationship between MeDi and stroke, and in particular, stroke subtypes. We hypothesized that MeDi would be associated with reduced total, ischemic, and hemorrhagic stroke incidence. Methods: The California Teachers Study comprises 133,478 women who enrolled in 1995 and have been continuously followed. Using linked California state hospitalization data and national death records from 1996-2011, incident strokes were identified and validated. Socio-demographic and medical risk factor data were collected from the baseline questionnaire. Diet was assessed using a food-frequency questionnaire in 113,547 women. The Mediterranean diet emphasizes plant-based foods, mono-unsaturated fats, fish and moderate alcohol intake. We used the MeDi adherence score, a nine point scale, which has been used and validated in prior studies. A higher score on the 0-9 scale represents increased adherence. Multivariable Cox proportional-hazard models adjusted for socio-demographic factors including age, ethnicity, socioeconomic status, moderate-to-strenuous physical activity, total calorie intake, body mass index, cigarette smoking, menopausal and hormonal status and vascular risk factors were used to assess the association (hazard ratios and 95% confidence intervals, HR 95% CI) between MeDi score and risk of stroke and stroke subtypes. Results: A total of 104,268 participants were eligible for the analysis (mean age 52 ± 13.9 years, 87.4% white, 4.6% Hispanic, 3.2% Asian and 2.1% black). The MeDi score distribution was: 0-2 (16.1%), 3 (18.2%), 4 (21.4%), 5 (20.1%), and 6-9 (24.3%). During follow-up, 3165 stroke events occurred (2270 ischemic ; 895 hemorrhagic). In the multivariable model, compared to those in the lowest MeDi score quintile (score 0-2), those in the fourth quintile (score 5: HR 0.86, 95% CI 0.75-0.98) and highest quintile (score 6 - 9: HR 0.83, 95% CI 0.73-0.95) were at lower risk of stroke (p for trend 0.009). For ischemic stroke, those in the third (HR 0.84, 95% CI 0.72-0.97), fourth (0.85, 95% CI 0.73-0.98), and highest quintile (HR 0.82, 95% CI 0.70-0.95) were all at reduced risk (p for trend 0.02). There was no association with hemorrhagic stroke. Discussion: Adherence to the Mediterranean diet is associated with decreased risk of total and ischemic stroke incidence among the participants of the California Teachers Study.