Human brains getting larger in size, and this may be good news for some

A new study has revealed that the size of human brains is getting larger, which means increased brain reserve and decreased chances of developing dementia. The researchers at UC Davis Health reached the conclusion by comparing the size of the brains of people born in the 1930s with those of people born in the 1970s. They noticed that the latter had 6.6 per cent larger brains. The study was 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.

He further adds that genetics may also play a major role in determining the size of the brain. "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," he said.

Add WION as a Preferred Source

How was the study conducted?

Researchers used brain magnetic resonance imaging (MRIs) from participants in the Framingham Heart Study (FHS). This community-based data was launched in 1948 in Framingham, Massachusetts to analyse patterns of heart diseases.

The original sample size was made up of 5,209 men and women between the ages of 30 and 62. The research continued for 75 years and later included second and third generations of participants.

Then, the MRIs were conducted between 1999 and 2019. The brain study was done on 3,226 participants (53 per cent female, 47 per cent male) with an average age of about 57 at the time of the MRI.

Result

For participants born in the 1930s, the average volume of the brain was found to be 1,234 millilitres but for those born in the 1970s, the volume turned out to be 1,321 millilitres, 6.6 per cent larger.

The researchers found brain structures such as white matter, grey matter and hippocampus (a brain region involved in learning and memory) also increased in size.

Benefits of larger brain size

Researchers said it might lead to decreased chances of developing dementia in ageing population.

"Larger brain structures like those observed in our study may reflect improved brain development and improved brain health," DeCarli said.

"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," he added.

(With inputs from agencies)