Mediterranean inspired diet and cardiovascular health. Experimental and clinical studies

Abstract

Cardiovascular diseases cause the majority of morbidity and mortality in the western countries. Inadjunct, the worldwide prevalence of overweight and obesity is a growing problem not onlyamong adults but also among children and adolescents. In the Mediterranean countries theincidence of cardiovascular disease is less common and the difference in diet is one possibleexplanation. The purpose of the present studies was to evaluate the effect of a Mediterraneaninspired diet concerning blood lipid levels, vascular function and inflammation, in healthy subjectsand to investigate whether obese adolescents at young age already have risk factors such asincreased left ventricular myocardial mass (LVM). In addition, to get further insight into themechanisms behind vascular vasomotion, blood flow and arterial pressure responds were studiedin terms of interacting influence between the nitric oxide- and endothelin-systems.The endothelial mechanistic study was performed according to two separate protocols, one inhealthy subjects and another in experimental animals. Venous occlusion plethysmography wasused in humans to determine forearm blood flow and Sprague-Dawley rats were instrumentedwith indwelling catheters and systemic blood pressure was recorded in a conscious state. Thedietary intervention study, in healthy subjects with a normal lipid profile, lasted for four weeks. Itwas conducted in a cross-over design with Mediterranean inspired diet and a normal Swedishdiet, respectively. Blood lipids and vascular function in terms of forearm blood flow, carotid arteryelasticity, oxidative stress and inflammation were assessed and the results after each dietcompared. In paper IV obese adolescents and lean age-matched controls were investigated forblood pressure, lipid levels and LVM using magnetic resonance imaging.Total cholesterol, LDL-cholesterol, Apo-B and triglycerides fell by of 17% (p<0.001), 22%(p<0.001), 16% (p<0.001) and 17% (p<0.05), respectively after the Mediterranean inspired diet.No difference in vascular function was observed between the two diets. A reduction in whiteblood cells and platelets was observed after the Mediterranean inspired diet compared to theSwedish.An increase in LVM as well as elevated insulin- and triglyceride levels and blood pressure wereseen in the obese adolescents. The HDL-cholesterol level was also reduced. However, onlysystolic blood pressure and body mass index remained independent factors determining LVM.We found that diet is of great importance even in subjects with normal lipid levels. AMediterranean inspired diet would be of even greater importance for individuals at increased riskfor cardiovascular disease although the events may appear many years later. Lifestyle changesneed to be emphasized when fighting overweight, obesity and cardiovascular disease.