People who have big families appear to be at amplified risk of heart disease, study suggests.

Two large British studies found out that people who had two children were at the lowest risk of developing coronary heart disease.

Those families who had more than two children appeared to have a considerably amplified risk – and the risk became larger for each additional child.

And researchers found that with increasing numbers of children, both parents were more likely to be obese.

Among women with more than two children, the risk of CHD increased by 30% with each additional child. For men the figure was 12% for each additional child.

Researchers studied 4,286 women and 4,252 men aged 60 to 79 who had from zero to five or more children.

The risks were also advanced for those people who had just one child, or who remained childless.

Mothers of more than two children were also more likely to have confirmation of insulin opposition, prominent blood sugar and diabetes.

They were also more likely to have low levels of good cholesterol and increased triglycerides.

During pregnancy women become for the short term insulin resistant allowing blood sugar levels to rise to feed the growing fetus.

It may be that multiple pregnancies increase the danger that this opposition – an essential risk factor for CHD – might become everlasting.