Gestational diabetes mellitus (GDM) poses significant risks to both mothers and infants, driven by hormonal changes during pregnancy that impair insulin utilization. Controlling blood glucose levels through medical and nutritional interventions is crucial to mitigate these risks.
Research suggests that lifestyle and dietary interventions, particularly before or early in pregnancy, can substantially lower the likelihood of neonatal diseases and improve maternal health outcomes. Conversely, diets rich in saturated fats, carbohydrates, cholesterol, and total fats have been linked to increased GDM risk.
The Mediterranean Diet (MedDiet), characterized by high consumption of whole grains, vegetables, legumes, monounsaturated fatty acids (MUFAs), and low intake of processed and red meats, has emerged as a potential preventive measure against GDM. While understanding the impact of individual dietary components is important, evaluating overall dietary patterns like the MedDiet may offer greater benefits in managing GDM.
Multiple studies have indicated that adherence to the MedDiet is associated with reduced GDM risk. A recent systematic review and meta-analysis synthesized findings from ten studies conducted across various countries, including the United States, Mediterranean regions, Australia, Iran, Spain, and Greece. The combined participant pool totaled 32,959,909 women aged 18-45 years.
Assessment of MedDiet adherence utilized different scoring systems such as Mediterranean Diet Adherence Screener (MEDAS), Alternate Mediterranean Diet (AMED) score, and Mediterranean-Style Dietary Pattern Score (MSDPS). GDM outcomes were determined using criteria like the National Diabetes Data Group and Obstetricians and Gynecologists criteria for glucose levels.
Key findings revealed that higher adherence to the MedDiet significantly correlated with lower GDM risk across the studies, albeit with some heterogeneity likely attributed to varying study designs and dietary assessment periods.
Case-control studies indicated a substantial 75% risk reduction in GDM among women with strong adherence to the MedDiet. In contrast, cohort studies demonstrated a more moderate 20% risk reduction. This disparity may stem from recall biases inherent in case-control studies, potentially inflating risk reduction estimates.
Subgroup analyses further supported the MedDiet’s beneficial effect across both Mediterranean and non-Mediterranean populations. The diet’s emphasis on whole grains, fruits, vegetables, nuts, olive oil, and legumes, supplemented with fish and seafood, contributes to higher intake of antioxidants and vitamins, which in turn mitigate oxidative stress and systemic inflammation—crucial factors in chronic disease development.
Moreover, the MedDiet’s high polyphenol content from fruits and vegetables has been shown to reduce GDM risk through mechanisms such as glucose absorption inhibition, anti-inflammatory effects, microbiota modification, and enhanced antioxidant capacity.
Evidence also suggests that the MedDiet’s ability to reduce obesity and insulin resistance—common risk factors for GDM—further supports its role in preventing the condition. Previous meta-analyses have underscored the diet’s potential to lower obesity and overweight risk by 9%.
Conversely, prolonged consumption of red meat has been associated with higher GDM risk, underscoring the potential protective effect of the MedDiet against this condition.
In conclusion, the systematic review and meta-analysis affirm a robust association between high adherence to the MedDiet before or during pregnancy and reduced risk of GDM. Recommending the MedDiet to women of reproductive age could thus serve as a valuable strategy for preventing GDM and related adverse pregnancy outcomes.
Nevertheless, future research should explore interactions between the MedDiet, genetic predispositions, and lifestyle factors to enhance preventive strategies against GDM effectively.