The size of the human brain has increased over time. A recent study shows that it has significantly enlarged in the last decades, which means that cases of dementia will be fewer in the future, scientists say.
A study conducted by scientists at the Davis University in California has shown that, for example, people born in the ’70s have brains almost 7% larger than those born in the ’30s.
The hippocampus, the brain region responsible for memory and learning, has increased by nearly 6% across the studied generations, according to Science Alert.
"The decade in which you were born seems to have an impact on brain size and its potential long-term health," explained neurologist Charles DeCarli, from the mentioned university, the author of the research.
"Genetics play a role in determining brain size, but our findings suggest that external influences – health, social, cultural, and educational factors – could also play a role," he added.
Other studies have shown that the incidence of dementia in Europe and America has decreased by 13% each decade in the last 30 years, a possible reason being a healthier lifestyle. And scientists say that this trend will most likely continue.
Dementia is marked by the thinning of gray matter, the cortex, which is involved in memory, learning, and reasoning, among other cognitive processes.
A diseased (dementia) brain shrinks over time, so having a larger brain volume from the start could help. Studies have shown that cognitive performance was better in Alzheimer's patients with larger brains.
However, not all scientists agree that a larger brain volume is closely related to a better "reserve." They all agree, though, that regular exercise helps when it comes to larger brain regions responsible for memory and learning. At the same time, alcohol consumption, social isolation, and an unhealthy diet have adverse effects.