Going to university may cut your risk of heart disease
"Why gaining a degree could help you live longer," The Daily Telegraph reports. A new gene study found people with genes associated with spending longer in education had around a 33% reduced risk of developing heart disease.
One of the practical difficulties about assessing the effects of education on heart health is the long gap between a person's time at school and university and the expected time when someone would be vulnerable to heart disease. The researchers estimated that the average length between the two could be around 50 years.
So researchers attempted to overcome this difficulty by looking at genetic variations known to be associated with spending more or less time in education. And then seeing if these variants had any corresponding effects on heart disease risk.
They found those with "longer education genes" (said to translate to around 3.6 years more in education) had a lower risk of heart disease than those with "shorter education genes".
And people with "longer education genes" were less likely to smoke and be overweight, both of which could contribute to heart disease risk.
But the use of these gene markers was very much an exercise in educated guesswork. We have no idea whether all people with "longer education genes" went to university, and similarly, whether people with "shorter education genes" left school at 16.
Where did the story come from?
The study was carried out by researchers from academic and research institutions from the UK, Poland, Lithuania, the Czech Republic, Russia, Brazil, Estonia and Italy.
It was funded by a range of institutions, including the Wellcome Trust, the Medical Research Council and the National Institute for Health Research. None of the funders had a role in the design, data collection, analysis, interpretation, or writing of the study.
The Daily Telegraph reported the research accurately, explaining that better educated people were also less likely to smoke, and more likely to have a lower BMI and a more favourable blood fat profile, all of which probably contributed to their lower risk of heart disease.
The Mail Online's reporting was more misleading, suggesting that a definite cause and effect relationship between time spent in education and heart disease risk had been proven. At best you could say that a possible relationship between the two may exist.
What kind of research was this?
This was a study looking at whether educational attainment (as measured by looking at the genetic variants linked to years of schooling) can affect the risk of developing coronary heart disease.
Coronary heart disease is a major cause of death worldwide and happens when the heart's blood supply is blocked or disrupted by a build-up of fatty substances causing narrowing and hardening of the coronary arteries. Known risk factors for developing coronary heart disease include smoking, having high blood cholesterol levels and having diabetes but the role of a person's education levels is not known.
What did the research involve?
Researchers analysed data from 707,903 participants mostly of European origin, to determine if there is a genetic link supporting the idea that education is a causal risk factor in the development of coronary heart disease (CHD).
They also aimed to see whether education influences other risk factors for cardiovascular disease.
They looked at 162 independent genetic variants associated with educational attainment, previously identified by the Social Science Genetic Association Consortium. These genetic variants were used as a proxy for randomly assigning 543,733 participants to "more education" or "less education".
The researchers then compared the CHD risk of the two groups of participants – using data from the Coronary Artery Disease Genome wide Replication and Meta-analysis plus the Coronary Artery Disease Genetics Consortium (CARDIoGRAMplusC4D) – to see if participants with genetic variants for longer education had a different CHD risk than those with genetic variants for shorter education.
They also looked at observational studies to see if there was an association between education and risk of CHD, using data collected between 1983 and 2014. They looked at data analysed from 164,170 participants from the National Health and Nutrition Examination Surveys (NHANES) and the Health, Alcohol, and Psychosocial factors In Eastern Europe (HAPIEE) study.
What were the basic results?
The data from the genetics study showed there were 63,746 CHD events (fatal and non-fatal).
- A genetic predisposition towards 3.6 years extra education was linked with a 33% reduced risk of CHD (odds ratio [OR] 0.67, 95% confidence interval [CI] 0.59 to 0.77).
- An extra 3.6 years of education (due to genetic predisposition) was linked with a 35% lower likelihood of smoking (OR 0.65, 95% CI 0.54 to 0.79), a lower body mass index (BMI) (OR 0.17, 95% CI 0.26 to 0.08) and more favourable blood lipids (triglycerides) (OR 0.14, 95% CI 0.22 to 0.06).
How did the researchers interpret the results?
The researchers conclude that this "study found support for the hypothesis that low education is a causal risk factor in the development of coronary heart disease. Potential mechanisms could include smoking, body mass index, and blood lipids. In conjunction with the results from studies with other designs, these findings suggest that increasing education may result in substantial health benefits."
This study indicates there may be some genetic support for the idea that spending longer in education contributes to lowering the risk of CHD. The researchers also demonstrate that this may be because people who spend longer in education have a lower BMI and are less likely to smoke.
However, there are some limitations to this research that need to be considered:
- The genetic variations identified as being associated with education may not be markers for education at all, but more basic biological pathways.
- The authors do not account for the fact that differences in education might be due to brain function, which also influences mental health, lifestyle and behaviour choices, all of which are likely to contribute to cardiovascular health.
- The research does not address whether the link between "longer education genes" and decreased risk of CHD might be down to educational ability rather than just length of time spent in education.
- The increased time in education might have led to increased wealth for many of the participants, which may contribute to the decreased risk of CHD.
You don't need to get a degree to reduce your risk of heart disease. You can lower your risk by having a healthy, balanced diet, being physically active and not smoking.
Read more advice about preventing heart disease.
Links To The Headlines
Why gaining a degree could help you live longer. The Daily Telegraph, August 31 2017
Links To Science
Tillmann T, Vaucher J, Okbay A, et al. Education and coronary heart disease: mendelian randomisation study. British Medical Journal. Published online August 30 2017