It is well known that education has many positive effects. People who spend more time in school are generally healthier, smarter, and have better jobs and higher incomes than those with less education. However, it was not yet known whether prolonged education causes long-term changes in brain structure and protects against brain aging.

It is challenging to study this because, in addition to education, many other factors influence brain structure, such as the conditions in which one grows up, DNA traits, and environmental pollution. However, researchers Rogier Kievit (PI of the Lifespan Cognitive Dynamics laboratory) and Nicholas Judd from Radboudumc and the Donders Institute found a unique opportunity to very precisely examine the effects of an additional year of education.

Aging

In 1972, a change in the law in the United Kingdom increased the number of years of compulsory schooling from fifteen to sixteen, while all other circumstances remained constant. This created an interesting “natural experiment,” an event beyond the researchers’ control that divides people into an exposed and unexposed group. Data is available from about 30,000 people who attended the school during that time, including MRI scans taken much later (46 years later). This data set is the largest collection of brain imaging data in the world.

The researchers examined the MRI scans for the structure of different brain regions, but found no differences between those who attended school more and those who did not. “This surprised us,” says Judd. “We know that education is beneficial, and we expected that education would protect against brain aging. Aging shows up in all of our MRI measures, for example we see a decrease in total volume, surface area, cortical thickness and worse water diffusion in the brain. However, the extra year of study seems to have no effect here.

The structure of the brain

It is possible that the brain looks different immediately after the extra year of education, but this was not measured. “Maybe education temporarily increases the size of the brain, but it returns to normal later. In the end, it has to fit in your head,’ explains Kievit. “It could be like sports: if you train hard for a year at sixteen, you’ll see a positive effect on your muscles, but fifty years later, that effect is gone.” It is also possible that additional education produces only microscopic changes in the brain that are not visible with MRI.

Both this study and other smaller studies found links between more education and brain benefits. For example, people who receive more education have stronger cognitive skills, better health, and a higher likelihood of employment. However, this is not visible in the structure of the brain by MRI. Kievit notes, “Our study shows that one should be cautious about attributing causality when only a correlation is observed. Although we also see correlations between education and the brain, we see no evidence of this in the structure of the brain.