Genetic insights from Scottish study reshape brain aging views

The research revealed significant differences in how the brain ages in different people in terms of both structure and function. More than half of the differences in intelligence in older individuals result from genetic predispositions and reflect discrepancies already present in childhood.

Prof. Ian Deary, the publication's author, points out: "What's particularly fascinating is that even after seven decades, we found correlations of about 0.7 between childhood and older-age cognitive scores." This means that slightly less than half of the variability in intelligence in old age was already present at age 11.

Researchers also noted that genes operate differently in childhood and old age. Individuals who are more intelligent in their youth tend to live longer, and the risk of death is linked to changes in the activity of certain genes.

The project was based on data from unique Scottish studies from 1932 and 1947, covering nearly all children born in 1921 and 1936. This extensive database allowed tracking cognitive changes throughout the participants' lives, revealing patterns previously unavailable to science.

The study's results prompt consideration of the factors influencing brain aging and whether they can be affected through lifestyle interventions. Scientists plan to investigate how cognitive abilities in childhood influence lifestyle choices, the role environmental factors play in maintaining cognitive abilities, and whether interventions in middle age can help preserve cognitive functions in later years.

We've learned that what we often assume are 'causes' of cognitive decline in older age are sometimes actually 'outcomes' of earlier cognitive differences — emphasizes Dr. Simon Cox.