Our Brains Are Getting Bigger — and Maybe Healthier
With all our modern education and technology, we might think we're smarter than people born a century ago. But are we really?
It's not quite clear, but scientists do think that over the last century our brains have been getting bigger.
A new study has found that people born in the 1970s had a 6.6% larger brain volume and 15% larger brain surface than people born in the 1930s.
According to the research team, it's possible that larger brains could reduce the risk of age-related dementia.
The researchers looked at MRI scans of participants in the Framingham Heart Study in the US. This is a health survey that began in 1948 and is now looking at its third generation of participants.
The MRI scans were done between 1999 and 2019, and more than 3,000 people were studied.
As well as increased brain size, the study found that brain structures including the hippocampus — the area that deals with learning and memory — have grown in size.
That's when comparing people born in the 1970s with those born in the 1930s, and when accounting for factors like increased body size.
The study's first author Charles DeCarli said larger brain structures "may reflect improved brain development and improved brain health."
He added: "A larger brain structure represents a larger brain reserve." This means the brain might be better able to deal with the damage that comes with getting older.
This could help reduce the risk of age-related brain diseases like Alzheimer's, DeCarli said.
The number of people living with Alzheimer's in the US has been increasing since the 1970s, as the population has grown and aged. But as a percentage of population, the rate has actually been decreasing by 20% per decade.
DeCarli thinks larger brains may have had an effect on this trend, but further research is required.
