A new study looking into the habitual consumption of chocolate of middle-aged people found that an ounce of chocolate, once a week, is linked to a reduced risk of developing type 2 diabetes.

The Main-Syracuse Longitudinal Study interviewed 908 healthy subjects and 45 subjects with type 2 diabetes in order to assess how often and how much chocolate they ate in a week.

They looked at those who hadn’t already been diagnosed with type 2 diabetes, to see if they had developed it five years and thirty years later, comparing the likelihood with the amount of chocolate they ate.

The self-reported data indicated that those who ate chocolate once a week in moderate amounts were at a lower risk of a diagnosis of diabetes over the next four to five years. However, the nature of self-reported data makes it less reliable than clinically gathered data on a small scale.

Consuming chocolate more than once a week, however, did not lower the risk any further.

The actual amount of chocolate eaten by these people per sitting of chocolate per week was also not recorded.

Chocolate can have dietary benefits because of a type of polyphenol found in cocoa called flavanols. These flavanols have anti-oxidant properties, and arte not only found in chocolate. Tea leaves, certain fruits and vegetables also have these anti-oxidant flavanols.

Researchers believe that low intakes of chocolate – as little as 25 grams – could be beneficial. This is a very small amount though, approximately a third of a typical chocolate bar. The type of chocolate is also very important, and this is a factor that the data in this study didn’t account for.

Dark chocolate contains the highest amount of flavanols, as it has the highest percentage of cocoa in it. Milk and white chocolate do not have as high a per cent as dark chocolate, and tend to have higher levels of sugar and fat in them, which can contribute to obesity and the risks of developing type 2 diabetes in itself.