Researchers from Umeå University, the University of Gothenburg and the National Board of Health and Welfare in Sweden have worked together to analyse data from a 25 year study monitoring diet and health in the north of Sweden.
Appearing in BioMed Central’s open access Nutrition Journal
, the review of the data demonstrates an overall increase in cholesterol levels and body mass index (BMI) despite an interventional programme introduced more than a quarter of a century ago designed to reduce fat intake.
The Västerbotten Intervention Programme (VIP) was introduced in northern Sweden in 1985 when it became apparent that the region had the highest risk of cardiovascular disease in the country. Indeed for the male population, the cardiovascular risk was one of the highest in the world.
The programme included (and still includes) cooking demonstrations, health examinations and counselling, advice on healthy eating, and better food labelling, and it was later rolled out across the entire country.
"The association between nutrition and health is complex," stated Professor Ingegerd Johansson, lead author of the study. "It involves specific food components, interactions among those food components, and interactions with genetic factors and individual needs."
Despite this complexity, the change effected by VIP was evident as early as 1992, when fat intake for men had been reduced by three per cent and for women by four per cent. These figures remained stable until 2005, when levels of total and saturated fat intake began to increase and eventually overtook 1986 levels. This was accompanied by a reduction in the amount of complex carbohydrates consumed, corresponding with the promotion in the media of low GI diets.
"While low carbohydrate/high fat diets may help short term weight loss, the results of this Swedish study demonstrate that long term weight loss is not maintained and that this diet increases blood cholesterol which has a major impact on risk of cardiovascular disease," Professor Johansson added.
Evaluation of the VIP was combined with information from the World Health Organization (WHO) MONICA project, which monitors cardiovascular risk factors.