Marbling Matters: Lean and Fatty Red Meat Show Opposing Associations with Brain Structural Indices

Area of Science:

• Nutritional epidemiology
• Neuroimaging
• Brain aging research

Background:

• Red meat is often studied as a uniform dietary group, masking variations in fat content and preparation.
• This heterogeneity may obscure true associations between meat consumption and brain health outcomes.

Purpose of the Study:

• To investigate how different types of red meat (lean, fatty, pork, processed pork, organ meat) are associated with global brain structure.
• To determine if meat's fat content and type influence brain aging markers.

Main Methods:

• Analysis of structural MRI data from 45,811 UK Biobank participants (aged 50-80).
• Dietary intake assessed via repeated 24-hour recalls (Oxford WebQ).
• Statistical models examined associations between meat types and global cortical thickness, gray matter volume, and white matter volume, with sensitivity analyses by socioeconomic status (SES) and sex.

Main Results:

• Associations with brain structure varied significantly by meat type and fat content.
• Lean red meat demonstrated neutral-to-favorable associations with brain structure, particularly cortical thickness and white matter volume in higher-SES individuals.
• Fatty red meat, pork, and organ meats were linked to less favorable brain structural outcomes, including reduced cortical thickness and gray matter volume, with some associations dependent on SES.

Conclusions:

• Meat consumption's impact on brain structure is not uniform; it depends critically on meat type, fat content, and socioeconomic context.
• Differentiating meat types in research is crucial for understanding brain aging and resolving conflicting findings.
• Precise dietary phenotyping, distinguishing meat quality, is recommended for future brain health studies.