Sarah Knapton, Telegraph, January 26, 2016
Some people really do win the genetic lottery.
For the first time, scientists have shown that intelligence is linked to good health, so those blessed with brains are also less likely to become sick, develop disease or die early.
The reason is down to genes. An international team, led by the University of Edinburgh, have discovered that the same gene variants which make people smart, also protect them against illness.
Those who performed the best on memory, verbal reasoning and reaction time tests, were less likely to have genes linked to high blood pressure, develop diseases like Alzheimer’s, diabetes or have poor overall health. They were also likely to be taller and have larger brains, the study found.
The only conditions that intelligence appeared to increase were schizophrenia, autism and bipolar disorder.
“The study supports an existing theory which says that those with better overall health are likely to have higher levels of intelligence,” said Dr Saskia Hagenaars, of Edinburgh University.
Dr Stuart Ritchie, also of Edinburgh added: “This study tests whether genes that are linked to mental abilities and educational attainment are also genes that are related to some disorders.
“We found that there are many overlaps: to take one example, genes related to being taller are also related to obtaining a college or university degree.
“We also asked whether the sets of genes associated with many disorders and traits predicted people’s actual levels of cognitive abilities. We found many overlaps there, too. To take one example, people with more genes linked to cardiovascular disease tended to have lower reasoning ability.”
To unpick the connection between gene variants, health and intelligence, researchers analysed data from more than 100,000 people between the ages of 40-73.
After comparing each person’s mental test data with their genome, they found that some traits linked to disease and thinking skills shared the same genetic influences.
The ‘super’ genes were also linked to being taller, and having a larger brain.
Previously scientists thought that socio-economic factors were largely to blame for the link between low education and poor health. But the new study suggests that genetics also plays a part. So intelligent people from a poor background have a better chances of staying healthier, than those who are less brainy.
Researchers hope the study will help understanding of some of the links between low levels of cognitive function and poor health.
Professor Ian Deary, Director of the Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE) at the University of Edinburgh, who led the research, said: “In addition to there being shared genetic influences between cognitive skills and some physical and mental health states, the study also found that cognitive skills share genetic influences with brain size, body shape and educational attainments.”
However the authors point out that there are many other environmental factors which influence health over time.
Dr. Sarah Harris, a lead author on the paper, said: “These conditions are also heavily influenced by environmental factors.
“This study did not address whether people with these conditions are more or less likely to have higher cognitive abilities or a degree than people without the conditions.”
The research was published in the journal Molecular Science.