Professor Janet Lord, who led the research, said: "There are a lot of anecdotes about couples who were married for 40 years when one of them passes away and then the other dies a few days later. It seems there is a biological basis for this.
"Rather than dying of a broken heart, however, they are dying of a broken immune system. They usually get infections."
The researchers came to the conclusion on an analysis of immune systems and hormone levels of 48 healthy adults aged 65 and over. Half of the group had suffered a major bereavement in the past 12 months.
