A new study finds brain size has steadily increased for people born after the 1930s

A new study by researchers at UC Davis Health found human brains are getting larger. Study participants born in the 1970s had 6.6% larger brain volumes and almost 15% larger brain surface area than those born in the 1930s.

The researchers hypothesize the increased brain size may lead to an increased brain reserve, potentially reducing the overall risk of age-related dementias.

The findings were published in JAMA Neurology.

“The decade someone is born appears to impact brain size and potentially long-term brain health,” said Charles DeCarli, first author of the study. DeCarli is a distinguished professor of neurology and director of the UC Davis Alzheimer’s Disease Research Center. “Genetics plays a major role in determining brain size, but our findings indicate external influences — such as health, social, cultural and educational factors — may also play a role.”