A new study links staying in school with a lower risk of heart disease.

The report says that increasing the number of years that people spend in the education system may lower their risk of developing coronary heart disease by a substantial amount.

It is a finding that has appeared in previous research, but the relationship between education and heart disease has remained unclear.

To better understand the nature of this association a team of researchers from University College London, the University of Lausanne, and the University of Oxford analysed 162 genetic variants already shown to be linked with years of schooling from 543,733 men and women, predominantly of European origin, using a technique called mendelian randomisation.

This technique uses genetic information to avoid some of the confounding factors in other types of studies, in order to make it more likely to be reliable in understanding cause and effect.

The authors found that genetic predisposition towards more time spent in education was associated with a lower risk of coronary heart disease.

Specifically, 3.6 years of additional education, which is similar to an undergraduate university degree, translated into about a one third reduction in the risk of coronary heart disease.

Genetic predisposition towards longer time spent in education was also associated with less likelihood of smoking, lower body mass index (BMI), and a more favourable blood fat profile.

The authors suggest that these factors could account for part of the association found between education and coronary heart disease.

The results remained largely unchanged after further sensitivity analyses and are in line with findings from other studies, and the effect of raising the minimum school leaving age.

The innovative technique does have some limitations. For example, it is not fully understood how genetic variants cause changes to the length of time spent in education, and this could have introduced bias.

But there are strengths too, including the large sample size and the use of genetic randomisation to minimise confounding.

The findings “should stimulate policy discussions about increasing educational attainment in the general population to improve population health,” the authors said.

The study is accessible here.