Previous research has indicated that there appears to be a link between poor health and both low socioeconomic status and low educational attainment. However, the link between intelligence and health is arguably more questionable. A team of researchers have this week provided a possible answer. Their study in the journal Molecular Psychiatry reveals that the genes that exert an influence over our health also affect our cognitive abilities.

In order to find evidence for such a link, the team led by the University of Edinburgh turned to the U.K. Biobank, a vast database containing medical information on half a million people living in the United Kingdom.

All of these subjects had provided blood, urine and saliva samples, had their genome at least partially sequenced, had their health status recorded, and underwent a rigorous series of mental reasoning examinations. Selecting 112,151 of these people for analysis, the team looked at any correlations between their genomes, mental reasoning abilities and physical health.

Mental health was also looked into, including the prevalence of neurodegenerative diseases like Alzheimer’s and psychiatric disorders like bipolar disorder. In order to reinforce their research, data from previous peer-reviewed genetic studies of other mental and physical health factors, including those that researched schizophrenia and autism, were also taken into account.

^{Although a genetic link between higher cognitive abilities and health has been demonstrated, the links between the two are incredibly complex. agsandrews/Shutterstock}

The researchers found that a selection of genes that are strongly linked to intelligence are also those that influence the physical and mental health of a person. In fact, their study shows that those with less advanced cognitive skills are more likely to suffer from ailments like coronary heart disease, type 2 diabetes, and dangerously high blood pressure – even if they are, at present, perfectly healthy individuals.

Mental health links were more complicated. Variants related to higher mental reasoning abilities were only linked to an increased risk of autism, with schizophrenia and bipolar disorder shown to have no such association. Counterintuitively, the study found that genetic variants associated with obtaining a college degree were also related to a higher risk of autism, schizophrenia, and bipolar disorder.

Links between intelligence and mental health disorders are known to be complex, with the authors noting that both very high and very low intelligence scores are linked to higher risks of certain neurological problems, including bipolar disorder. However, when it came to neurodegenerative diseases, this study also demonstrated that those with higher cognitive abilities were less likely to suffer from such conditions, including Alzheimer’s.

Ultimately, this study shows that intelligence and health are linked on a genetic level. A significant flaw is that environmental factors weren't taken into account. Regardless, the authors conclude that their findings imply that intelligent people tend to be healthier individuals.