Linking Personality Traits to Mediterranean Diet Adherence and Exploring Gene-Diet Interactions in Neuroticism

There is adherence to a healthy Mediterranean diet (MedDiet), but adherence varies widely. Precision nutrition is increasingly interested in individual characteristics influencing diet adherence, but few studies have examined personality traits. Our main aim was to investigate the association between personality traits and MedDiet adherence. Our secondary aims were to explore genome-wide genetic variants associated with neuroticism, including replication of previous findings, as well as to explore gene-MedDiet interactions.

We analyzed participants (aged 55-75) in the PREDIMED-Plus-Valencia study and measured clinical, lifestyle, and genetic factors. The Eysenck Personality Questionnaire-Revised (EPQ-R) was used to measure neuroticism, psychoticism, and extraversion. Genotyping was undertaken, and associations with candidate SNPs, genome-wide association studies (GWAS), genetic risk scores (GRS), and gene-MedDiet interactions were explored.

Neuroticism was inversely (beta = -0.09; p = 0.001) associated with adherence to the Mediterranean diet (MEDAS-17). Likewise, the probability of low MedDiet adherence increased neuroticism (OR: 1.27; 95% CI: 1.02-1.60; p = 0.031 per SD). In the GWAS for this trait, several SNPs surpassed the suggestive level of statistical significance. The most strongly associated was rs10181407-NDUFA10 (NADH dehydrogenase 1 alpha subcomplex subunit 10) (beta = -2.39; p = 2.70 × 10^-6). The GRS for neuroticism was significantly associated with MedDiet adherence (beta = -0.18; p = 0.020), increasing the causality level. We replicated some candidate SNPs, and among them, the rs2243873-EHMT2 (euchromatic histone lysine methyltransferase 2) gene. The analysis of gene-MedDiet interactions revealed the role of these dietary modulations.

Neuroticism was the personality trait most inversely associated with MedDiet adherence, suggesting its integration in precision nutrition analysis. Moreover, neuroticism-related genetics and MedDiet modulations will also be important.