Fish consumption and brain structure: a comprehensive systematic review of observational studies

Area of Science:

• Neuroscience
• Nutritional Science
• Gerontology

Background:

• Aging brains undergo structural changes like atrophy and lesions, contributing to cognitive decline.
• White matter hyperintensities (WMH) and cerebral microbleeds are key indicators of brain aging and vascular damage.
• While fish intake is linked to slower cognitive decline, its impact on brain structure needs comprehensive evaluation.

Purpose of the Study:

• To systematically review human studies on the relationship between fish consumption and brain structure.
• To synthesize evidence on how dietary fish intake affects age-related brain changes.

Main Methods:

• Systematic literature search of major electronic databases using relevant keywords and MeSH terms.
• Inclusion of studies assessing fish consumption in relation to brain structures in adult populations.
• Analysis of data from 24 eligible studies, primarily using magnetic resonance imaging (MRI) for brain assessment.

Main Results:

• Higher fish consumption correlated with reduced white matter hyperintensities (WMH) and cerebral microbleeds.
• Preservation of brain volumes in areas like the hippocampus, temporal lobe, and periventricular white matter was observed with higher fish intake.
• Increased cortical thickness in regions such as the precuneus and parietal grey matter was associated with greater fish consumption.

Conclusions:

• Incorporating fish into a balanced diet is associated with improved white matter integrity and reduced vascular lesions in aging brains.
• Fish consumption may help prevent neurocognitive deterioration by mitigating age-related brain changes.
• Further research is needed due to heterogeneity across studies and potential influence of overall dietary patterns.