All brains shrink with age, and the dominant view has been that more education slows the rate of shrinking. However, the evidence has been inconclusive because studies have not been able to track the rate of change over time. Until now.

Measured brain shrinkage over time

A team of researchers measured brain aging by measuring the volume of the cortical mantle and hippocampus regions of the brain, in MRI scans from more than 2000 participants in the Lifebrain and UK biobanks. These areas of the brain are prone to shrinkage over time, as a natural part of aging. Participants' brains were scanned up to three times over an 11 year period, in what is known as a 'longitudinal' study.

"This is what makes this study unique," says Nyberg. "The study is a large-scale longitudinal test, with replication across two independent samples, and is one of the largest of its kind."

The researchers compared the rate of the shrinkage of these areas in people who had attained higher education before the age of 30 and those without. The participants ranged from 29-91 years of age.

Higher education is modestly related to bigger brains

Whereas the rate of brain change was similar in participants with and without high education, the researchers found that those with high education had slightly larger cortical volume in a few regions, but even in these regions the rate of change was unrelated to education.

"The study does not say that education is not important," stresses Anders Fjell from the University of Oslo, also one of the main authors of the paper.

"Education is associated with advantages in life, but we cannot from this study say whether education caused these advantages. If people with high education have larger brains to begin with, this may delay the onset of dementia or other conditions associated with lower cognitive functioning," says Fjell.

"The bottom line is that all people's brains shrink eventually, but the rate of this shrinkage does not seem to be affected by how many years you spent in school," concludes Fjell.