Parahippocampal Cortex Mediates the Relationship between Lutein and Crystallized Intelligence in Healthy, Older Adults.
Level 4 - case-series / case-control
Cross-sectional observational study assessing biomarker levels, neuroimaging metrics, and cognitive scores without longitudinal follow-up or intervention.
PubMed 27999541 · doi:10.3389/fnagi.2016.00297
What was done
Researchers evaluated 76 cognitively intact adults aged 65 to 75 to investigate whether temporal cortex gray matter volume/thickness mediates the link between serum lutein concentrations and crystallized intelligence (measured by the Wechsler Abbreviated Scale of Intelligence). A three-step mediation analysis used multivariate linear regression controlling for age, sex, education, income, depression status, and body mass index.
What was found
The abstract reports that gray matter thickness of the right parahippocampal cortex (Brodmann's Area 34) partially mediated the relationship between serum lutein and crystallized intelligence. No numerical effect sizes, regression coefficients, or p-values were reported in the abstract.
Why it matters
The study suggests a specific structural neural pathway—the parahippocampal cortex—through which circulating lutein may support preserved crystallized cognitive abilities in late life.
Limits
The study is cross-sectional and observational, preventing causal conclusions. The sample size is modest (n = 76), and the abstract provides no numerical data or effect sizes. Results from cognitively intact older adults cannot be generalized to cognitively impaired groups.
Cited by
- supports Lutein and zeaxanthin accumulate in the human brain and are associated with improved cognitive function, crystallized intelligence, and reduced brain aging.