New study on a healthy Nordic diet
Long-term, well-prepared and implemented diet studies give new, reliable understanding of how nutrition affects our health. Recently, experts have been more interested than ever in the importance of a comprehensive diet to health, i.e. dietary patterns, rather than the effects of individual nutrients. The best-known dietary pattern is the Mediterranean diet, which has been the subject of most research into effect on health, and has become an international brand.
SYSDIET - a Nordic Centre of Excellence on Food, Nutrition and Health - was founded in 2007. One of its aims is to define the healthy properties of food by identifying the effects of its quality. SYSDIET’s dietary intervention study was conducted in Finland, Sweden, Denmark and Iceland assisted by Norwegian partners.
Initially, it involved 200 subjects with sugar metabolism problems,i.e. so called impaired glucose metabolism but not overt diabetes. Altogether 166 of them completed the entire study, which lasted 18–24 weeks. During the period, they either kept strictly to a healthy, Nordic diet or a conventional diet. The effects of the two types of diet were compared. An important aspect of the study was that the body weight of the subjects did not change during the period, to be able to establish the effects of the quality of the food.
Surprising reduction in the level of inflammatory factors
Compared with a control diet, the healthy Nordic diet improved the body's ability to metabolise fat by reducing the level of harmful cholesterol, LDL cholesterol, and enhancing the level of "good" cholesterol, HDL cholesterol, to improve the balance between them. The amount of harmful lipid particles was also reduced. The changes in cholesterol levels are believed to reduce the risk of coronary diseases by up to 10–15% over a period of 5–10 years. The diet also meant 1.5–2 times higher uptake of several important minerals and vitamins.
To the surprise of the researchers, the level of inflammation factor IL-1 Ra was reduced by no less than 20% in people who kept to a healthy Nordic diet, compared with conventional diets. Higher levels of IL-Ra are believed to be the most sensitive marker of metabolic syndrome, a risk indicator of type 2 (adult onset) diabetes, and the level also rises in connection with fatty liver.
The diet had no significant influence on sugar (glucose) metabolism, possibly because the weight of the study subjects remained unchanged. Initial observations also indicate that a healthy Nordic diet may reduce blood pressure registered over a period of 24 hours, even though it has no particular influence on routine blood pressure taken at an outpatient clinic. By reducing inflammation response, a healthy Nordic diet can also reduce the body's oxidative stress.
The researchers will also investigate how diet and food components affect the activity and function of the genes, and hundreds of by-products from metabolism in the organism. Detailed research into bacteria content in faeces is also planned.
How to compose a Nordic diet
A healthy Nordic diet can also be composed according to the principle of locally-sourced foods. Hard animal fat and milk fat are replaced by rapeseed oil (turnip rape) and plant oil based margarine, and fat-free or low fat dairy products are recommended. One is also recommended to eat plenty of domestic seasonal fruits, which in the Nordic countries means apples, pears and plumbs, berries, vegetables, root vegetables, legumes and cabbage, plus wholegrain products made from rye, barley or oats every day. Nuts can also be part of the diet, low-fat and fatty fish 2–3 times a week, plus game and poultry. Red meat and sausages should be eaten in moderation.
The SYSDIET study has been published on the website of the Journal of Internal Medicine
The SYSDIET consortium was one of three Nordic centres of research excellence within the Nordic Centres of Excellence Programme on Food, Nutrition and Health between 2007–2012, set up and financed by NordForsk.