Lingonberries have been found to prevent weight gain in mice fed a high-fat diet, a study at Lund University in Sweden has found.

Researchers used mice that easily store fat as a model for humans who are overweight and at risk of diabetes.

The mice were split into groups and fed either lingonberries, bilberries, raspberries, crowberries, blackberries, prunes, blackcurrants or açai berries.

After three months the group that were fed lingonberries had the lowest blood sugar and insulin levels.

The study is the first of its kind to use lingonberries, eaten mainly in Scandavia and often sweetened in jam or compotes.

Karin Berger, diabetes researcher at Lund University, said: “Up to 20 per cent of our mice’s diet was lingonberries. It isn’t realistic for humans to eat such a high proportion.

“The goal is not to produce such dramatic effects as in the ‘high-fat’ mice, but rather to prevent obesity and diabetes by supplementing a more normal diet with berries.”

Berger said that the Brazilian açai berries came last, although they had actually been included in the study for the opposite reason, as researchers wanted to test how well Nordic berries would compare.

The açai berry is regarded as a ‘super berry’ in Europe and North Americawith health benefits including weight loss.

But Berger said in Brazil the açai berry is regarded more as an energy supplement.

Researchers said they do not recommend people start eating large quantities of lingonberry jam. They said that boiling the berries can affect their nutrient content and said that frozen lingonberries on cereal or in a smoothie are considerably better.

The study was held at the Antidiabetic Food Centre, a research centre at Sweden’s Lund University that aims to prevent diabetes with food.

Lingonberries, also know as cowberries, red whortleberries or foxberries, are native to the Northern Hemisphere. They are popular in Scandavia served as a garnish with reindeer.