Relationship between daily eating habits and occurrence of stroke in the O City Cohort I survey: a 26-year follow-up of residents in rural Japan

Objective: This study aimed to elucidate the relationship between daily eating habits and stroke risk factors in O City, Ehime Prefecture, Japan, using stroke registry data collected over a 26-year follow-up period based on standardized national criteria.

Materials and methods: Overall, 1,793 middle-aged Japanese participants (446 men and 1,347 women) who completed a 33-item Food Frequency Questionnaire (FFQ) and had no history of stroke were matched to those from O City in a stroke registry from 1996 to 2022. Stroke diagnosis for each person was used to determine whether this was their first documented stroke, and we classified strokes as either a cerebral infarction (CI) or a hemorrhagic stroke (HS), the latter which included an intracerebral hemorrhage (ICH) or a subarachnoid hemorrhage (SAH). A Cox proportional hazard regression model was used to examine the association between habitual dietary intake and the occurrence of stroke, using the following covariates: age, body mass index, elevated blood pressure/hypertension, dyslipidemia, prediabetes/diabetes, alcohol consumption, and smoking.

Results: During the 26 years of follow-up, 45 men (10.1%) and 76 women (5.6%) had stroke. The CI rate was 70.2% (n=85; 38 men, 47 women). The HS rate was 29.8% (n=36; 7 men and 29 women); of these patients, 26 and 10 had ICH and SAH, respectively. In men, orange intake showed a significant inverse correlation with CI. In women, fresh fish intake showed a significant inverse correlation with CI, while yogurt intake showed a significant inverse correlation with HS.

Conclusion: Our results indicated that fresh fish intake was significantly associated with the prevention of CI among women in a Japanese cohort survey.