An Okinawan-based Nordic diet improves anthropometry, metabolic control, and health-related quality of life in Scandinavian patients with type 2 diabetes: A pilot trial

Background: Our hypothesis was that a modified diet would improve blood glucose control with beneficial impact on weight management and overall health in established diabetes. Objective: This prospective interventional study investigated the clinical effect of an Okinawan-based Nordic diet on anthropometry, metabolic control, and health-related quality of life (HRQoL) in Scandinavian type 2 diabetes patients. Design: Food was prepared and delivered to 30 type 2 diabetes patients. Clinical information along with data on HRQoL, blood samples, and urine samples were collected during 12 weeks of diet interventions, with follow-up 16 weeks after diet completion. Results: After 12 weeks of dietary intervention, a reduction in body weight (7%) (p < 0.001), body mass index (p < 0.001), and waist circumference (7.0 cm) (p < 0.001) was seen. Improved levels of proinsulin (p = 0.005), insulin (p = 0.011), and fasting plasma glucose (p < 0.001) were found already after 2 weeks; these improved levels remained after 12 weeks when lowered levels of C-peptide (p = 0.015), triglycerides (p = 0.009), total cholesterol (p = 0.001), and low-density lipoprotein-cholesterol (p = 0.041) were also observed. Insulin resistance homeostasis model assessment for insulin resistance was lowered throughout the study, with a 20% reduction in hemoglobin A1c levels (p < 0.001) at week 12, despite reduced anti-diabetes treatment. Lowered systolic blood pressure (9.6 mmHg) (p < 0.001), diastolic blood pressure (2.7 mmHg) (p < 0.001), and heart and respiratory rates (p < 0.001) were accompanied by decreased cortisol levels (p = 0.015) and improvement in HRQoL. At follow-up, increased levels of high-density lipoprotein-cholesterol were found (p = 0.003). Conclusion: This interventional study demonstrates a considerable improvement of anthropometric and metabolic parameters and HRQoL in Scandinavian type 2 diabetes patients when introducing a modified Okinawan-based Nordic diet, independently of exercise or other interventions. Through these dietary changes, anti-diabetes treatment could be decreased or cancelled.