Unveiling the causal relationships between circulating metabolites and intelligence: A bidirectional Mendelian...

Area of Science:

• Metabolomics
• Neuroscience
• Genetics

Background:

• Observational studies suggest a correlation between circulating metabolites and intelligence.
• The causal relationship between metabolites and intelligence remains unclear.
• Investigating these links is crucial for understanding cognitive function.

Purpose of the Study:

• To assess the causal influence of circulating metabolites on intelligence using a 2-sample Mendelian Randomization (MR) study.
• To explore bidirectional causal relationships between metabolites and intelligence.
• To identify specific metabolites that may causally affect intelligence.

Main Methods:

• Utilized summary statistics from genome-wide association studies (GWAS) for metabolites (19,273 individuals) and intelligence (269,867 individuals) in European ancestry populations.
• Employed a bidirectional MR analysis with methods including inverse variance weighted (IVW), MR-Egger, weighted median, and others.
• Conducted sensitivity analyses (heterogeneity, pleiotropy, leave-one-out) to ensure robustness of findings.

Main Results:

• Omega-6 fatty acids demonstrated a protective causal effect on intelligence (OR: 1.019).
• Glycoprotein acetyls, VLDL particle concentration, small HDL triglycerides, tyrosine, and VLDL particle diameter showed anti-protective effects (ORs < 1).
• Reverse MR indicated a causal effect of intelligence on omega-6 fatty acids (OR: 0.886).

Conclusions:

• The study provides suggestive evidence for a causal association between specific circulating metabolites and intelligence.
• Omega-6 fatty acids may play a protective role, while other metabolites might negatively impact intelligence.
• Further research is needed to elucidate the biological mechanisms underlying these metabolite-intelligence relationships.