Human brains are getting bigger, here’s why that’s good news

By Sharin Hussain via SWNS

The human brain is getting bigger which could be good news in the battle to beat dementia.

The surface area of a modern brain is around 15 percent larger than in the 1930s, researchers have found, with the volume increasing by 6.6 percent.

A team from the University of California Davis analyzed 75 years' worth of brain changes between generations.

Dr. Charles DeCarli, director of the UC Davis Alzheimer’s Disease Research Center said: “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.”

The study, published in the journal JAMA Neurology used brain magnetic resonance imaging (MRIs) from participants in the Framingham Heart Study (FHS) from 1999 and 2019.

This was launched in 1948 in Massachusetts, to analyze patterns of cardiovascular and other diseases.

The original cohort consisted of 5,209 men and women ages 30 to 62.

The research has continued and now includes second and third generations of participants.

These participants were born during the 1930s through to the 1970s.

Dr DeCarli, added: “The decade someone is born appears to impact brain size and potentially long-term brain health.

“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.”

The brain study consisted of 3,226 participants, with 53 percent female and an average age of about 57 at the time of the MRI.

Researchers found gradual but consistent increases in several brain structures.

For participants born in the 1930s, the average brain volume was 1,234 milliliters, compared to 1,321 milliliters for those born in the 1970s, or about 6.6 percent greater volume.

But the cortical surface area, a measure of the brain’s surface, showed an even greater increase over time.

Those born in the 1970s had an average surface area of 2,104 square centimeters compared to 2,056 square centimeters for participants born in the 1930s, almost a 15 percent increase in area.

The researchers found brain structures such as white matter also increased in size when comparing the two groups.

A previous study found a 20 percent reduction in the incidence of dementia per decade since the 1970s.