Diet–Gene Interaction Between Fruit Intake and CMIP rs2925979 Polymorphism in Relation to Type 2 Diabetes: A Family-Based Study in Northern China

<b>Background/Objectives</b>: This study aimed to investigate the association between dietary intake and the risk of type 2 diabetes mellitus (T2DM) in a rural northern Chinese population, and to explore potential gene-diet interactions that may influence T2DM susceptibility. <b>Methods</b>: A total of 1747 participants (1138 with T2DM and 609 without) were included, using baseline data from a family-based cohort study in rural northern China. Demographic characteristics, lifestyle factors, and medical history were collected via standardized questionnaires. Dietary intake was assessed using a semi-quantitative food frequency questionnaire, and anthropometric measurements were conducted according to standardized protocols. Based on findings from previous genome-wide association studies, several T2DM-related single-nucleotide polymorphisms were selected for genotyping. Generalized linear models accounting for familial clustering were employed to examine the associations between dietary intake and T2DM risk, and to assess gene-diet interaction. <b>Results</b>: A significant inverse association was observed between fruit intake and T2DM risk. Furthermore, a significant interaction was found between fruit consumption and the <i>CMIP</i> rs2925979 polymorphism: the protective effect of higher fruit intake was evident among individuals carrying the T allele but not among those with the CC genotype. <b>Conclusions</b>: These findings suggest that genetic variation may modify metabolic responses to dietary factors, particularly fruit intake. The results underscore the importance of considering gene-diet interactions in the prevention of T2DM.