Constant bitterness can actually make a person ill, a new university study warned yesterday. Researchers who examined the link between failure, bitterness and quality of life found that blaming others could lead to physical disease. Prof Carsten Wrosch, of Montreal’s Concordia University, said persistent bitterness can cause biological dysregulation- a physiological impairment that can affect metabolism, immune response or organ function and ultimately, a physical disease. Unlike regret, which is about self-blame, it points the finger elsewhere- laying the blame for failure on external causes. He said bitterness could be avoided, if people who experience failure could find other ways to fulfill their goals. If they could not, it was essential to stop the fruitless effort such as trying to get promoted or saving a doomed marriage.