UMEA, SWEDEN — A study examining 25 years of diet among Swedes found an association between an increase in diets low in carbohydrates and high in protein and an increase in total cholesterol levels. The study appeared on-line June 11 in Nutrition Journal. It involved 68,457 men and 72,931 women.

The researchers based their findings on the Northern Sweden Diet database, which includes information from two population-based studies — the Vasterbotten Intervention Programme (VIP) and the Northern Sweden MONICA study.

The VIP, launched in 1985, emphasizes reducing high cholesterol levels through intake of a Mediterranean diet and increased physical activity. The diet involves a shift from saturated fats to polyunsaturated fatty acids, fewer eggs, and more vegetables, legumes, fruit, fish and whole grain bread.

In 1986, men’s mean reported energy intake, adjusted for age and body mass index, was 39.2% for fat, 45.9% for carbohydrates and 13.6% for protein. For women in 1986, the levels were 35.5% for fat, 49.2% for carbohydrates and 14.3% for protein.

Reported fat intake from 1986 to 1992 fell 2.9% in men and 4.4% in women. Surveys from the Northern Sweden MONICA study revealed the use of butter and high-fat milk declined from 1986-99 in favor of low-fat milk products. Total cholesterol levels in serum decreased continuously from 1986 to 2004.

Fat intake levels began to increase in the years 2002 to 2004. An increase in total cholesterol levels in serum followed, beginning in 2007. During the decade a low-carbohydrate, high-fat diet became popular as a way to try to lose weight and control blood glucose levels among Swedes with type 2 diabetes. By 2010, fat intake levels were above 1986 levels with men at 39.9% and women at 37.7%.

The researchers noted cholesterol-lowing medication was introduced during the 25-year period.

Researchers also noted consumption of boiled potato and whole grain crisp bread decreased while rice, pasta and whole grain soft bread consumption increased. Mean body mass index over the 25-year period increased to 27.1 from 25.5 in men and to 25.9 from 24.8 in women.

The study involved Swedish researchers from Umea University in Umea, the National Board of Welfare in Stockholm, Skelleftea County Hospital in Skelleftea, and the University of Gothenburg in Goteborg. The study’s authors said they had no competing interests.

Grants from the Swedish Research Council, the Swedish Research Council Formas, the Swedish Council for Working Life and Social Research, and the Vasterbotten and Norrbotten County Councils supported the study.