New Research Shows Our Brains Are Getting Larger, Which May Help Lower Dementia Incidence

Though the number of dementia cases are expected to rise substantially in the coming decades, the actual incidence – or percentage of the population that develops the disease – has been going down. New research indicates it may have something to do with a gradual increase in brain volume.

Researchers from UC Davis Health recently studied the brain volumes of people born between the 1930s and the 1970s to see if there were generational differences. This was a point of interest because human brain development and maintenance are thought to be linked with dementia risk later.

The study involved more than 3,200 participants from the long-running Massachusetts-based Framingham Heart Study, which follows participants long-term to better understand disease development. The people included in this current study, who were split nearly evenly between men and women, had MRIs to measure their brain, hippocampal, gray matter, and white matter volumes, along with their cortical surface area and thickness. These figures were then compared to the decade in which each person was born.

According to the findings, published in JAMA Neurology, the later a participant was born, the bigger their brains. Compared to those born in the 1930s, participants born in the 1970s had a 6.6% larger brain volume, a 5.7% larger hippocampal volume, 7.7% more white matter, and a 14.9% larger cortical surface area.

The findings suggest that gradually increasing brain volumes may have something to do with the recent decreases in dementia incidence, a trend that has also been reflected in the Framingham Heart Study cohort. The team believes this may be because the brain has an increased reserve to draw from.

Charles DeCarli, the study’s first author and director of the UC Davis Alzheimer’s Disease Research Center, says, “Larger brain structures like those observed in our study may reflect improved brain development and improved brain health. A larger brain structure represents a larger brain reserve and may buffer the late-life effects of age-related brain diseases like Alzheimer’s and related dementias.”

To read more about our apparently expanding brains, click here.