Fish intake and MRI burden of cerebrovascular disease in older adults

Abstract

Background

Cerebrovascular disease (CVD), a major contributor of cognitive aging, is characterized by subclinical damage visualized on brain MRI, including covert brain infarcts, white matter hyperintensities (WMH) and dilated perivascular spaces (dPVS). Few protective factors for brain vascular health, that may help prevent stroke and dementia, have been identified so far. Fish intake may prevent ischemic events and small vessel disease. When investigating factors with a pleiotropic effect such as fish, there is interest to capture pathophysiological burden globally, combining biomarkers into a single metric. Here, we investigated the association of fish intake with a global indicator of the MRI burden of CVD among older adults.

Method

This Three-City Dijon study included 1,623 participants (≥65 years) without history of dementia, stroke or cardiovascular disease, who had completed a Food Frequency Questionnaire and underwent brain MRI with automated assessment of WMH, visual detection of covert infarcts, and grading of dPVS. A global indicator of CVD burden was estimated using a factorial analysis of mixed data; association of fish intake with the indicator was assessed by adjusted linear regression.

Result

The proportions of participants consuming fish less than once a week, once a week, 2 to 3 times and more than 4 times per week were 11%, 37%, 47% and 6%, respectively. The continuous CVD burden indicator, derived from the first dimension of the factorial analysis (32.4% of explained variance), was associated with a higher WMH load, more infarcts and higher dPVS severity. Higher fish intake was associated with a lower CVD burden indicator (P for trend <0.001). Compared to participants consuming fish less than once a week, the CVD indicator decreased by -0.19 units (95% CI, -0.37; -0.005) for those consuming fish 2-3 times per week and by -0.31 units (-0.59; -0.03) for ≥4 times per week. These effect estimates of eating fish at least twice a week were equivalent to having a 4 to 5 years younger brain in terms of vascular health (β = 0.05 units (0.03; 0.06) for each one year increase of age).

Conclusion

Fish consumption may promote brain vascular health before manifestation of overt brain disease.