The Effect of Nordic Recommended Diet on the Features of Metabolic Syndrome - Multicentre Study

SYSDIET (Systems biology in controlled dietary interventions and cohort studies) is one of the three centres in the NCoE Food, Nutrition and Health, 2007-2011. It consists of 12 partners from five Nordic countries working on multidisciplinary fields of science related to nutritional biology. The main objective of SYSDIET is to reveal mechanisms by which Nordic foods and diets could be modified to promote health and prevent insulin resistance, type 2 diabetes and cardiovascular diseases, all of which being connected to metabolic syndrome. Furthermore, the aim is to build up a Nordic platform for cohort studies and carefully conducted multi-centre dietary intervention studies, where novel nutritional systems biology tools can be applied besides human studies also in animal and cell culture studies. In order to achieve the main objective a Nordic multi-centre randomized controlled human intervention study is being conducted in 2009-2010 in 6-8 centres of SYSDIET consortium.

Health of the Nordic populations has substantially improved during the last 30 years. This is due e.g. to marked decline in cardiovascular morbidity and mortality. However, during the last 10-20 years increasing obesity and sedentary lifestyle have resulted in an increase of metabolic syndrome and type 2 diabetes.

Having this background, the aim of the SYSDIET consortium is to carry out a controlled, randomized dietary intervention study in persons with features of metabolic syndrome to find out the effects of a healthy Nordic food on major abnormalities in metabolic syndrome.

Altogether 167 persons aged 30 to 65 years were recruited from 6-8 centers (40-60 subjects/center) of the SYSDIET cohort. The main inclusion criterion is BMI 27-38 kg/m2. The subjects should also have at least two other IDF criteria for metabolic syndrome. Recruited persons will start the study by following their conventional diet for one month as a run-in period. After that subjects will be randomly assigned into Experimental- or Control-diet-group for 6 months. Experimental diet is rich in whole grain products, berries, fruits, vegetables and fish, and its fat intake is modified according to current Nordic recommendations. Control diet is based on the current information of the mean dietary intake and food consumption. The diets will be realized according to eating habits in each Nordic country.

Substudy of the multicentre SYSDIET-study has been conducted in one of the centres, Aarhus, Denmark.

This study aims was determine if a "Healthy Nordic Diet (HND)" fulfilling the Nordic Nutrition Recommendations does affect 24-h ambulatory BP in subjects with features of Metabolic Syndrome. Of the 167 SYSDIET subjects with MeS, 37 were enrolled in a Danish sub study on 24-h ambulatory BP performed at 0 and 12 wks after randomization. 32 completed the sub study. All maintained stable body weight, physical activity level, medicine, and alcohol habits during the intervention, as prescribed.

Eligibility Criteria:
Inclusion Criteria:

* Age 30-65 years old
* BMI 27-38 kg/m2
* + two other IDF criteria for metabolic syndrome
* Anti-hypertensives and lipid-lowering medication are allowed

Exclusion Criteria:

* Fasting plasma glucose \> 7.0 mmol/l
* Fasting plasma triglycerides \> 3.0 mmol/l
* Fasting plasma total cholesterol \> 6.5 mmol/l
* Blood pressure \> 160/100 mmHg
* Preceding weight change of 5% or more or active weight loss during preceding 6 months
* Any disease or condition that may hamper the successful participation of the intervention: liver disease, kidney disease, diabetes (both type 1 and type 2), thyroid disease (Newly found unstabilized disease), Myocardial infarction within previous 6 months
* Alcohol abuse (\> 40 g/day)
* Oral corticosteroid therapy
* Severe psychiatric disorders
* Cancer under treatment
* Coeliac disease
* Exceptional diets (Atkin's, vegan, allergies to fish or cereals, other extensive allergies)
* Binge eating
* Unwillingness to discontinue the use of fish and vegetable oil or stanol and sterol ester supplements or products