Firstborn children run a much higher risk of developing heart disease, according to a study.Scientists have discovered that eldest children could be up to 60 per cent more likely to suffer from Britain's biggest killer than younger siblings.
And parents could be partly to blame by putting pressure on firstborn children which makes them competitive and aggressive.
Researchers in Italy believe firstborns may have a more 'coronaryprone' personality, called 'type A' by doctors, marked by increased competitiveness.
They studied 348 patients with coronary heart disease and found that first- born children were hugely overrepresented in the group.
Some 46.7 per cent of the patients were eldest children, even though only 29 per cent of people in the general population are firstborn.
That suggests firstborns are up to 60 per cent more likely to suffer with heart disease.
Dr Maurizio Ferratini said: 'After many years of practice, we noticed a prevalence of first- borns among people affected by coronary heart disease.
'Primogeniture, a term for the eldest child, has been considered a possible determinant of various diseases but, to our knowledge, its association with coronary heart disease has never been investigated.' Dr Ferratini, head of the cardiovascular rehabilitation unit of Fondazione Don Carlo Gnocchi in Milan, added: 'Personality may play a role because of the particular personalities of firstborns and how they develop.
' The family context frequently orients them along a perfectionist path, giving them a determined, competitive, winning and aggressive attitude - aspects frequently observed in subjects with a type A personality also known as "coronary-prone".
'Biological factors, social and environmental variables and educational opportunities are different in firstborns than other children.' The scientists looked for other risk factors linked to being firstborn, but found no significant differences between firstborns and their siblings in terms of family health history.
'Because we found the same kinds of risk factors in both groups, we suspect primogeniture is the likely explanation and should be regarded as a determinant of heart disease that is independent of other risk factors studied,' said Dr Ferratini.
A spokesman for the British Heart Foundation said: 'In the long term, further large-scale research in a variety of locations is needed to gain a better understanding of the importance of being firstborn as factor in the development of coronary heart disease.
'Until then people should be aware that there are many factors proved to increase your risk of developing coronary heart disease such as smoking, lack of physical activity and diets that are high in salt and saturated fat.'
Heart disease is the UK's biggest killer, causing 124 , 000 deaths in a year - one in four male deaths and one in five female.
