Summary: Regular consumption of fish was associated with a lower burden of vascular brain disease on MRI scans in older adults, a condition that can increase the risk of stroke and vascular dementia.
Source: Alzheimer’s Research UK
Researchers in France report that higher fish consumption is linked to reduced signs of vascular brain disease. Vascular brain disease reflects damage to the brain’s blood vessels and is a known risk factor for vascular dementia and stroke.
This research appears in the journal Neurology.
Investigators at the University of Bordeaux drew on data from the Three-City Study, a large cohort designed to examine the relationship between vascular conditions and dementia in older adults.
The analysis included MRI scans from 1,623 people aged 65 and older who had no prior history of stroke, diagnosed cardiovascular disease requiring hospitalization, or dementia. Participants also completed a dietary questionnaire documenting how often they ate fish.
Participants were grouped by fish consumption frequency: less than once per week, about once per week, two to three times per week, and four or more times per week. The researchers compared the extent of MRI markers of cerebrovascular disease across these groups.
Those who reported eating fish more frequently showed fewer MRI signs of vascular brain damage than those who ate fish rarely. The association was strongest in the younger segment of the cohort (ages 65–69) and was not statistically significant in participants aged 75 and older.
Dr. Rosa Sancho, head of research at Alzheimer’s Research UK, commented: “Dementia risk arises from a complex mix of genetic and environmental factors. Identifying lifestyle choices that support brain health helps people make informed decisions about their long-term wellbeing.”
She emphasized that observational studies cannot prove cause and effect. “Although the investigators adjusted for many potential confounders, it remains difficult to attribute differences in subclinical vascular brain damage solely to fish intake. The study used a single MRI and a single dietary assessment, so it does not capture long-term diet or changes over time.”
“Public health guidance, such as the NHS recommendation of two portions of fish per week, reflects the broader cardiovascular benefits of fish, particularly oily varieties that provide essential fatty acids. However, no single food or supplement is likely to be a magic bullet for brain health.”
“Evidence shows that measures good for heart health—controlling blood pressure and cholesterol, avoiding smoking, limiting alcohol, and staying physically active—also support brain health as we age.”
About this neurology and diet research news
Author: Press Office
Source: Alzheimer’s Research UK
Contact: Press Office – Alzheimer’s Research UK
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Original Research: Closed access. “Fish Intake and MRI Burden of Cerebrovascular Disease in Older Adults” by Aline Thomas et al., Neurology
Abstract
Fish Intake and MRI Burden of Cerebrovascular Disease in Older Adults
Background and Objective:
Fish consumption may help prevent cerebrovascular disease, but the biological pathways remain unclear, particularly in relation to subclinical brain damage detectable on MRI. Assuming fish intake could exert multiple beneficial effects on cerebrovascular health, the study examined the association between reported fish intake and a composite measure of cerebrovascular disease burden based on MRI markers.
Methods:
This cross-sectional analysis used data from the Three-City Dijon population-based cohort of adults aged 65 and older without dementia, stroke, or a history of hospitalized cardiovascular disease. Brain MRI scans were evaluated automatically for white matter hyperintensities, visually for covert infarcts, and graded for dilated perivascular spaces. Fish intake was assessed with a food frequency questionnaire. The primary outcome was the first component from a factor analysis of mixed MRI markers, and linear regression models evaluated the relationship between fish intake frequency and the cerebrovascular disease (CVD) burden indicator.
Results:
A total of 1,623 participants (mean age 72.3 years; 63% women) were included. The first factor component, explaining 32.4% of variance, corresponded to higher levels across all three MRI markers. Greater fish intake was associated with a lower CVD burden indicator. After adjusting for total intracranial volume, compared with participants consuming fish less than once per week, those eating fish two to three times per week and four or more times per week had β = -0.19 (95% CI, -0.37 to -0.01) and β = -0.30 (95% CI, -0.57 to -0.03), respectively (P trend < 0.001).
The association showed effect modification by age: it was stronger in participants aged 65–69 and not significant in those aged 75 and older. In the younger group, eating fish two to three times weekly had an effect on the CVD indicator roughly comparable in magnitude (but opposite in direction) to the effect of hypertension.
Discussion:
In this large, population-based sample of older adults without overt brain disease, more frequent fish consumption was associated with a lower burden of subclinical cerebrovascular disease on MRI, particularly among participants younger than 75 years. These findings suggest a potential protective effect of fish intake on brain vascular health before clinical manifestations arise, though causality cannot be established from this cross-sectional analysis.
Classification of Evidence:
This study provides Class II evidence that, among individuals without stroke or dementia, higher fish intake is associated with lower subclinical cerebrovascular disease burden on MRI.