London: People in good relationships and marriages suffer less from the diseases of ageing, such as heart attacks and stress, a joint US-UK study has found.

The research which was carried out by Rosalind Barnett of Brandeis University in the U.S. and Professor Andrew Steptoe of University College London found unhappily married people suffer more physical signs of stress, such as higher blood pressure, than those who are in good relationships.

Stress is a known trigger for heart attacks, and those who are constantly stressed are also more likely to overeat, smoke and drink too much alcohol.

The study looked at 105 men and women aged between 52 and 62 who were married or in long-term relationships and examined their home lives and relationships.

The researchers measured blood pressure and used saliva tests to show levels of the stress hormone cortisol. They also asked the participants how stressed they felt at regular points over the course of a day.

The participants answered relationship questions such as whether their partner was critical of them and listened to them. Feelings of irritability and distress were also gauged.

The study, published in the journal Annals of Behavioural Medicine, found clear signs that those in unhappy marriages were more stressed throughout the day than those in good relationships.

The unhappy people had higher levels of cortisol and worse blood pressure than those in good marriages. They also reported feeling stressed many more times.