A Healthy Nordic Diet and Cardiometabolic Risk Factors : Intervention Studies with Special Emphasis on Plasma Lipoproteins

Sammanfattning: A healthy diet is important in the prevention of cardiovascular disease (CVD). Several risk factors, modifiable by diet, are involved in the development of CVD, e.g. hyperlipidaemia, hyperglycaemia, insulin resistance, obesity and hypertension. Little data however exist on diets composed of foods originating from the Nordic countries, and their potential to reduce CVD risk.This thesis aimed to investigate whether an ad libitum healthy Nordic diet (ND), either provided as a whole diet, or as a prudent breakfast (PB) alone, could influence CVD risk factors in healthy, mildly hypercholesterolemic men and women. Another aim was to describe the nutrient and food composition of the ND, both by using self-reported data and serum biomarkers of dietary fat quality.The primary clinical outcome measure was LDL-cholesterol, and other cardiometabolic risk factors were secondary outcomes.Two parallel, randomised, controlled intervention studies were conducted in free-living subjects. Clinical and dietary assessments were performed at baseline and at the end of dietary interventions. All foods were provided to subjects randomised to ND, whereas only breakfast items were supplied to subjects randomised to PB. Control groups followed their habitual diet/breakfast.Compared with controls, ND reduced body weight and improved several CVD risk factors including LDL-cholesterol, insulin sensitivity and blood pressure. Several, but not all effects were probably partly mediated by diet-induced weight loss. ND accorded with Nordic nutrition recommendations and was defined as “a plant-based diet, where animal products are used sparingly as side dishes”. Compared with average Swedish diet, ND was high in dietary fibre, but low in sodium, meat, high-fat dairy products, sweets and alcohol. A decreased intake of saturated fat and increased intake of n-3 PUFA during ND was partly reflected in serum lipids. Eating a PB without other dietary changes did not improve lipid or glucose metabolism, but decreased markers of visceral fat and inflammation, without influencing body weight.This thesis suggests that a whole ND, but not PB alone, promotes weight loss and improves multiple CVD risk factors in healthy subjects after 6 weeks. These results suggest that ND could have a potential role in the prevention of cardiometabolic diseases.