People who enjoy themselves without feeling guilty are less likely to become ill, according to researchers at Hull University.
Eating chocolate, drinking, shopping and sex were all given the seal of approval by Geoff Lowe and John Greenman of the medical research laboratory.
Thirty healthy students took part in the study. They listed the things they enjoyed doing then rated them for pleasure or guilt. They were then tested for levels of an antibody known as IgA.
The researchers completed a further study linking academic stress and levels of IgA. Levels of IgA increased immediately after verbal tests, which suggests an immune boost linked to relief that the ordeal is over.