Finnish researchers have discovered that a genetic mutation, which itself has a very strange effect on behavior, can possibly also protect people from obesity and insulin resistance.

The mutation in question, a variation of the serotonin 2B receptor, has been indicated by past studies to increase the impulsiveness of people, especially when they are drunk.

It is known as HTR2B Q20*, and it is through the link with serotonin, a mood and behavior regulator, that it affects the way people behave. However, the mutation has only so far been seen in Finnish people, with roughly 100,000 people so far identified with it.

However, in a study undertaken at the University of Helsinki, evidence has been found that it can have these extra health benefits, which are related to type 2 diabetes.

The study was investigating several health markers in people with antisocial personality disorder (ASPD), including the presence of HTR2B Q20*. They also analyzed insulin resistance, insulin sensitivity, beta cell activity and glucose metabolism.

The researchers looked at the beta cell activity, insulin sensitivity and BMI of 98 Finnish men between the ages of 25 and 30, all of whom had been diagnosed with antisocial personality disorder. Out of all the subjects, nine were found to have this mutation.

It was found that these nine participants tended towards a lower BMI and a lower insulin resistance than those without the mutation. This shows that those with the mutation may be less at risk of type 2 diabetes.

Furthermore, in those people with the mutation, it was found that a lower amount of testosterone appeared to be beneficial to further protection from type 2 diabetes risk factors. This was surprising as normally a higher level of testosterone is seen to be protective, but the serotonin mutation appears to have flipped this.

The findings appear in the Journal of Psychiatric Research.