Impact of Mediterranean diet education versus posted leaflet on dietary habits and serum cholesterol in a high risk population for cardiovascular disease

Objective: To investigate the impact of intensive group education on the Mediterranean diet on dietary intake and serum total cholesterol after 16 and 52 weeks, compared to a posted leaflet with the Dutch nutritional guidelines, in the context of primary prevention of cardiovascular disease (CVD). Design: Controlled comparison study of an intervention group given intensive group education about the Mediterranean diet and a control group of hypercholesterolaemic persons given usual care by general practitioners (GPs). Setting: A socioeconomically deprived area in the Netherlands with an elevated coronary heart disease (CHD) mortality ratio. Subjects: Two hundred and sixty-six hypercholesterolaemic persons with at least two other CVD risk factors. Results: After 52 weeks, the intervention group decreased total and saturated fat intake more than the control group (net differences were 1.8 en% (95%CI 0.2-3.4) and 1.1 en% (95%CI 0.4-1.9), respectively). According to the Mediterranean diet guidelines the intake of fish, fruit, poultry and bread increased in the intervention group, more than in the control group. Within the intervention group, intake of fish (+100%), poultry (+28%) and bread (+6%) was significantly increased after 1 year (P < 0.05). The intensive programme on dietary education did not significantly lower serum cholesterol level more (-3%) than the posted leaflet (-2%) (net difference 0.06 mmol l(-1), 95%CI -0.10 to 0.22). Initially, the body mass index (BMI) decreased more in the intervention group, but after 1 year the intervention and control group gained weight equally (+1%). Conclusions: Despite beneficial changes in dietary habits in the intervention group compared with the control group, after 1 year BMI increased and total fat and saturated fat intake were still too high.