Beneficial Effect of the Mediterranean Diet on the Reduction of Prediabetes—Results of the Bialystok PLUS Study

<b>Background:</b> The Mediterranean diet is considered one of the healthiest and safest diets for preventing chronic diseases. The primary objective of this study was to assess the association between adherence to the Mediterranean diet and the occurrence of prediabetes in a representative population of Bialystok, Poland. Prediabetes is a condition characterized by elevated blood glucose levels that are higher than normal but not yet in the diabetic range, indicating an increased risk of developing type 2 diabetes. <b>Methods:</b> The study participants were selected into healthy control (HC) and prediabetic (PreD) groups based on age and gender. Biochemical measurements included total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), fasting glucose (FG), glycated hemoglobin (HbA1c), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6). Additionally, blood pressure, handgrip strength, anthropometric parameters, and body composition were measured. Information on patients' social data, medical history, and lifestyle history was collected using questionnaires developed for this study. A standardized questionnaire, the Satisfaction with Life Scale (SWLS), was used to assess life satisfaction. Dietary total antioxidant capacity (DTAC) and dietary total polyphenol intake (DTPI) were determined using a 3-day nutritional interview and appropriate databases containing information on polyphenols and the antioxidant potential of food products. To assess adherence to the Mediterranean diet recommendations, a 9-item Mediterranean Diet Index (MDI) was used. <b>Results:</b> It was found that the mean MDI for the entire group was low (3.98 ± 1.74), and the HC was characterized by a significantly higher MDI compared to the PreD. A statistically significant positive correlation was found between MDI and HDL-C, whereas a negative correlation was found between MDI and FG, homeostatic model assessment for insulin resistance (HOMA-IR), diastolic blood pressure (DBP), IL-6, body mass index (BMI), waist-hip ratio (WHR), waist circumference, visceral fat mass, android/gynoid fat ratio. <b>Conclusions:</b> Abdominal obesity was shown to significantly reduce life satisfaction. In model 3, after adjusting for age, sex, dietary energy intake, alcohol consumption, and smoking, each additional MDI point indicated a 10% lower risk of prediabetes.