The interplay of persistent organic pollutants and Mediterranean diet in association with the risk of gestational diabetes

OBJECTIVE: Certain foods characterizing alternate Mediterranean diet (aMED) are high in persistent organic pollutants (POPs), which is related to greater gestational diabetes (GDM) risk. We examined the associations of combined aMED and POPs exposure with GDM.
RESEARCH DESIGN AND METHODS: aMED score of 1572 pregnant individuals was derived from food frequency questionnaires (FFQ) at early pregnancy within the U.S. Fetal Growth Study and plasma concentrations of 76 POPs, including organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and per-and poly-fluoroalkyl substances (PFASs), were measured. Associations of combined exposure to aMED score and POPs with GDM risk were examined by multivariable logistics regression models.
RESULTS: 25 of 53 included POPs have a detection rate above 50%. 3.88% (61/1572) of women were reported with GDM diagnosis. Higher POP levels appeared to diminish potential beneficial associations of aMED score with GDM risk, with lowest GDM risk observed among women with both high aMED score and low POP concentrations. Specifically, adjusted LogOR (95% CI) of GDM risk comparing women with low PCB and high aMED score with those with ow aMED score and high PCB concentrations is -0.74 (-1.41, -0.07). Inverse associations were also observed among women with low aMED score, and high TransNo_chlor, PCB182_187, PCB196_203, PCB199, and PCB206, respectively. These associations were more pronounced among individuals with overweight or obesity.
CONCLUSIONS: Pregnant women with healthy Mediterranean diet but low POP concentrations have the lowest GDM risk. Future endeavors to promote a healthy diet to prevent GDM may consider concurrent POPs exposure.