How you really can die of a broken heart

It really is possible to die of a "broken heart", according to research that has revealed how bereavement can weaken the body's ability to fight off infections.

Scientists found that the emotional stress of losing a loved one could lead to parts of the immune system being suppressed, leaving grieving relatives more vulnerable to infections from bacteria.

The findings could help to explain cases of widows and widowers who died days or even hours after their spouse.

Lord Callaghan, the former prime minister, died of pneumonia aged 92 in 1995, just 10 days after Audrey, his wife of 67 years.

Johnny Cash, the musician, died of complications related to diabetes while in hospital in 2003 at the age of 71. It was said at the time that he had been left weakened by the grief of losing his wife June, 73, four months previously.

Immunologists at the University of Birmingham found that increased stress levels and depression brought on by grief could interfere with the function of a type of white blood cell known as neutrophils, which are responsible for fighting bacterial infections such as pneumonia.

The impact became more profound in older adults because they had lost the ability to produce a hormone that can counteract this dampening affect, meaning even previously healthy elderly people could fall victim to disease.

Prof 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 studied the immune systems and hormone levels of 48 healthy adults aged 65 and over. Half of the group had suffered a major bereavement in the previous 12 months. They found that the antibacterial action of neutrophils in grieving participants was significantly reduced compared with those who had not suffered a bereavement. The bereaved also had raised levels of the stress hormone cortisol.

Cortisol is known to suppress the activity of neutrophils, making them less active. Most young healthy people produce a second hormone called DHEA, which can counteract this affect, allowing their immune system to function normally. With age, however, adults lose the ability to produce this second hormone and become more vulnerable to disease at times of stress.

The researchers also found that suffering a hip fracture could lead to the same hormone imbalance. This could explain why around a quarter of people over the age of 80 die within a year of suffering a hip fracture. Prof Lord said: "In healthy adults who have suffered bereavement, the stress response and the effect on the immune system was as profound as in those who had suffered a hip fracture.

"We think that even previously healthy people are becoming very depressed and this has a powerful effect on the immune system."