POOR DIETING PATTERNS UP CVD RISK FACTORS

While low-carbohydrate/high-fat diets may help short-term weight loss, results of a new study published in BioMed Central’s open access journal Nutrition Journal demonstrate that long-term weight loss is not maintained and the diet increases blood cholesterol and elevates the risk of cardiovascular disease.

The 25-year study in Northern Sweden is the first to show that a regional and national dietary intervention to reduce fat intake, decreased cholesterol levels, but a switch to the popular low-carbohydrate diet was paralleled by in an increase in cholesterol levels.

In the 1970s, men in northern Sweden had among the highest rates of cardiovascular diseases (CVD) worldwide. The Västerbotten Intervention Program (VIP) was set up in 1985 to address this and was later extended to include the entire country. The VIP included better food labeling, healthy information, cooking demonstrations and health examinations and counseling, including diet advice, and still continues today.

Evaluation of this program was combined with data from the WHO MONICA project which monitors cardiovascular disease risk factors. Researchers from Umeå University, University of Gothenburg and The National Board of Welfare collaborated on the study to examine trends in food and nutrient intake, serum cholesterol and body mass index (BMI) from 1986 to 2010 in northern Sweden.

The impact of the VIP was clearly seen in the changing intake of fat and carbohydrate. By 1992 the fat intake for men had reduced by 3% for men and 4% for women and remained stable until 2005. Not only did fat intake reduce due to VIP but the types of fat changed, for example from butter to low fat spreads, which was mirrored by a decrease in cholesterol levels. After 2005 the levels of total and saturated fat intake began to increase, returning to levels above those in 1986, and the amount of complex carbohydrates eaten decreased. The timing of this matched the promotion of low-GI diets in the media. Consequently cholesterol levels began to once more increase despite the introduction of cholesterol lowering medication.

"The association between nutrition and health is complex. It involves specific food components, interactions among those food components, and interactions with genetic factors and individual needs," the researchers said.