Human brains are getting bigger, which could reduce the risk of dementia

A new study found that human brains are getting bigger and that this may be associated with a lower risk of insanity . According to researchers from University of California – Davis Healthborn in the 1970s had 6.6% larger brain volumes and the area of brain surface almost 15% larger than those born in the 1930s.

The findings were published in the scientific journal JAMA Neurology at the end of March and raise the hypothesis that the Increased brain size can lead to increased brain reserve potentially reducing the risk of age-related dementia.

“Genetics plays an important role in determining brain size, but our findings indicate that external influences – such as health, social, cultural and educational factors – may also play a role,” said Charles DeCarli, first author of the study and professor of neurology at the UC Davis Alzheimer's Disease Research Center in press release.

Study reveals brain changes between generations

To arrive at their findings, the researchers used magnetic resonance imaging of the brains of participants in the Framingham Heart Study (FHS). This study was launched in 1948 in Framingham, Massachusetts, to analyze patterns of cardiovascular disease and other health conditions.

At that time, 5,209 men and women aged between 30 and 62 were analyzed. The research has continued for 75 years and now includes new generations of participants.

The MRIs were carried out between 1999 and 2019 with participants born between the 1930s and 1970s. The brains of 3,226 men and women were studied, who were, on average, 57 years old when they underwent the imaging test.

Researchers in the current study compared the MRIs of those born in 1930 with those born in 1970. They found changes in brain structures, such as brain (intracranial) volume, which steadily increased decade after decade .

According to the study, the average brain volume was 1,234 milliliters for participants born in the 1930s, while in those born in 1970, the average volume was 1,321 milliliters — about 6.6% larger.

Furthermore, the surface area of ​​the brain also increased decade after decade, according to the researchers. In the second group (1970), the average surface area was 2,104 square centimeters, while in the first group (1930), it was 2,056 square centimeters. This means there was an increase of almost 15% when comparing both groups.

Finally, the researchers also found that other brain structures, such as white matter, gray matter and the hippocampus (the region responsible for learning and memory) also increased in size in participants born in the 1970s compared to those born in the 1930s.

“Larger brain structures, like those observed in our study, may reflect better brain development and health,” says DeCarli. “A larger brain structure represents a greater brain reserve and may buffer the late-life effects of age-related brain diseases such as Alzheimer’s and related dementias,” he adds.