Scientists have identified many new genes associated with better thinking skills following a major international study.
A team led by the University of Edinburgh found significant small signals from 148 genomic regions that were related to having better cognitive function.
Fifty eight of these genetic signals have not been reported before.
These regions contained genes that have previously been associated with better brain structure, and with lower risk of neurodegenerative and neurodevelopmental disorders, and physical and psychiatric illnesses.
Scientists said the results could help understanding of the declines in cognitive function that happen with illness and as people age.
The study analysed data from 300,486 people aged between 16 and 102 who had taken part in 57 cohort studies in Australia, Europe and North America.
Dr Gail Davies, of University of Edinburgh’s Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), who led the analysis, said: “This study, the largest genetic study of cognitive function, has identified many genetic differences that contribute to the heritability of thinking skills.
“The discovery of shared genetic effects on health outcomes and brain structure provides a foundation for exploring the mechanisms by which these differences influence thinking skills throughout a lifetime.”
The study found that the genetic signature associated with increased general cognitive function is also associated with better cardiovascular and mental health, decreased risk of lung cancer, and longer life.
Those who participated in the study had all taken a variety of thinking tests which were summarised as a general cognitive ability score.
All had genetic testing that examined their DNA and none of the people had dementia or a stroke.
Lead researcher and CCACE director Professor Ian Deary said: “Less than a decade ago we were searching for genes related to intelligence with about 3,000 participants, and we found almost nothing.
“Now, with 100 times that number of participants, and with more than 200 scientists working together, we have discovered almost 150 genetic regions that are related to how clever people are.
“We’ve also learned that we need even larger studies to see more of the picture. We also need to study our results closely to see what they can tell us about the possibility of understanding the declines in cognitive function that happen with illness and in older age.
“One thing we know from these results is that good thinking skills are a part of good health overall.”
The study, published in Nature Communications, involved researchers in Australia, Austria, Croatia, Finland, France, Germany, Holland, Iceland, Ireland, Norway, Sweden, and the US.
