How long we live depends on many factors, but there is increasing focus on how important education is for health and long life.

What makes some people live longer than others?  Each individual has a multitude of risk factors: genes, daily behaviour such as smoking, diet and exercise, the lasting influence from early life conditions and an element of luck.

Looking at large groups of people who share one or more characteristics allow some generalisations to be made about what factors affect average lifespan.  For instance, the fact that women live longer than men on average has been observed in nearly all countries, with the exceptions being explained by specific factors.  So a woman in a developed country can safely say she is likely on average to live longer than a man of otherwise similar characteristics – but of course there are still any number of reasons which account for one actually living longer than the other.

Trends across large populations help us to understand what characteristics are associated with people being more likely to suffer bad health and die early. The World Health Organisation considers the Social Determinants of Health “mostly responsible for health inequities – the unfair and avoidable differences in health status seen within and between countries”. These Social Determinants of Health are the conditions in which people live. These conditions are affected by culture and the physical environment, as well as policy choices on, for example, the distribution of incomes, education, housing, employment, transport, and healthcare.

Analysis of the Social Determinants of Health stepped up a gear just over ten years ago. Professor Michael Marmot in the Lancet gave numerous examples of populations with higher (worse) mortality than others which have better markers on the socio-economic gradient. However, the problem was, and still is to a large extent, that the “causes of the causes” are not well understood. Exactly how does lower socio-economic status lead to a higher mortality risk? What facets of socio-economic status should policy focus on?

The level of education is sometimes used as a proxy measure for socio-economic status. Compelling evidence that education is one of the stronger factors driving how long we live has emerged quite recently.

For example, Anne Case and Angus Deaton showed how significantly the mid-life health and mortality of white non-Hispanic Americans worsened in the early years of the millennium.  For non-white Hispanics aged 45 to 54, mortality rates (from all causes) increased from 1999 to 2013 by 34 deaths per 100,000 lives.  That means that in 2013, for every 100,000 lives starting the year in that group, 34 more died than was the case from 100,000 lives in 1999. The general, worldwide trend of longevity improvement leads us to expect fewer deaths from similarly defined groups over time – as was the case for the other groups studied (black non-Hispanic and Hispanic Americans aged 45-54).

Further subdividing the non-white Hispanic group shows a remarkable difference between those with less than a high school level of education and those with more.  Out of 100,000 with a BA degree or higher level of education, there were 57 fewer deaths in 2013 than 1999. For 100,000 who have less than a high school level of education, there were 134 more deaths. The sharp increase in the death rate from external causes including drug and alcohol poisoning, self-harm and chronic liver cirrhosis explain a distressingly large part of this mortality trend.

The worsening mortality highlighted by Case & Deaton was overwhelmingly concentrated among people who had lower levels of education.  Similar studies show similar results.

There is some impatience among demographers that the role of education as a direct influence on mortality, independent of socio-economic status, is underappreciated.  A strong case that education can lead directly to better health and lower mortality has been made: education should improve decision-making abilities which can be applied to self-assessing risks and self-managing health. A side effect of education is often networks of relationships which can offer the social support important for health and longevity. Note that the education here means the level of general school and higher education; this is not about education on a particular subject.

This explanation of how education can lead to better health and longer life only adds to the importance of education policy. It also helps to create policy responses for specific health issues. For example, a policy requiring relatively complex risk assessment and decision making, such as a laissez-faire personal responsibility approach to diet or exercise is suited to highly-educated people. In contrast, a policy of simplifying decisions, such as removing energy-dense food from default shopping locations, would benefit those most at risk of poor health.