The analysis of nearly 4,000 patient records from the 30-year Framingham Offspring Study may help explain a widely documented association in developed countries between education and lower risk of heart disease, according to lead author Eric Loucks, assistant professor of community health at Brown University in Rhode Islad.

“Does education influence heart disease? One of the ways to get at that is to see if education is related to the biological underpinnings of heart disease, and one of those is blood pressure,’ said Louks.

Why the gender differences are pronounced

Controlling only for age, the study found that women with 17 years or more of education - a master's degree or doctorate - had systolic blood pressure readings 3.26 mm of mercury lower than female high school drop-outs.

Men who went to graduate school had systolic blood pressure readings that were 2.26 mm of mercury (mmHg) lower than their counterparts who did not finish high school, said the study, published online in the open access journal BMC Public Health.

That the gender differences are so pronounced and appear to become more so as life goes on suggests that education may have a greater impact on women’s health over their lifetime than on men’s health, Loucks said. That could be because of the correlation between low educational attainment and other health risk factors found in other studies of women.

“Women with less education are more likely to be experiencing depression, they are more likely to be single parents, more likely to be living in impoverished areas and more likely to be living below the poverty line,” Loucks said.

Graduate degree-holders benefit most

The same inverse relationship between education and blood pressure was also seen, although to a lesser degree, in men and women who got associate's or bachelor's degrees at university but did not continue on to graduate school.

They showed greater blood pressure benefits than high school drop-outs but lesser benefits than holders of master's degrees or doctorates, the study found.

Even after controlling for influences such as smoking, drinking, obesity and blood pressure medication, the benefits persisted, although at a lower level.

How to improve public health

The study could help explain the widely documented association in developed countries between education and lower risk of heart disease, said Loucks.

Blood pressure is "one of the biological underpinnings of heart disease", he said, and added that the study contributes to a chorus of others suggesting that policy makers who want to improve public health and are struggling to do it in other ways, might want to look at improving access to education.

“Socioeconomic gradients in health are very complex,” he said. “But there’s the question of what do we do about it. One of the big potential areas to intervene on is education.”