New role for IQ in heart disease rates

By Jane Collingwood

IQ may have a big effect on risk of developing heart disease, researchers reported yesterday.

Mental capacity may be responsible for as much as half the differences in disease rates between different social groups, researchers claimed.

A team of researchers from the Medical Research Council at Glasgow University, UK, examined the link using figures from 4,289 former US soldiers.

Analysis showed that IQ explained up to 50 per cent of the difference in death rates from heart disease between people from disadvantaged backgrounds and those from more advantaged backgrounds.

Full results are published in the European Heart Journal today (July 15). Lead researcher, Dr David Batty, said: "We already know that socio-economically disadvantaged people have worse health and tend to die earlier from conditions such as heart disease, cancer and accidents.

"Environmental exposures and health-related behaviours, such as smoking, diet and physical activity, can explain some of this difference, but not all of it. This raises the possibility that, as yet, unmeasured psychological factors need to be considered."

He explains that IQ – a person’s ability to reason and problem solve – is strongly related to socio-economic status. "When we took into account IQ we found this explained approximately 50 per cent of the difference in mortality," he said.

"This psychological variable has additional explanatory power on top of the classic variables such as smoking, high blood pressure, high blood glucose and obesity."

Responding to the findings, Professor Peter Weissberg of the British Heart Foundation said: "If we are to make real progress on tackling health inequalities we need health campaigns designed to reach everyone in the community and an environment that makes healthy choices easy choices for the whole population."

Batty, D. et al. Does IQ explain socio-economic differentials in total and cardiovascular disease mortality? Comparison with the explanatory power of traditional cardiovascular disease risk factors in the Vietnam Experience Study. The European Heart Journal. doi:10.1093/eurheartj/ehp254.