Human Brains Are Increasing in Size, Potentially Lowering Dementia Risk

Recent studies show a significant increase in brain volume and surface area in individuals born in the 1970s compared to those born in the 1930s, suggesting a possible decrease in the incidence of dementia.

Researchers found that brains of people born in the 1970s are 6.6% larger in volume and nearly 15% larger in surface area than those born in the 1930s.
The increase in brain size is hypothesized to contribute to a larger brain reserve, potentially reducing the risk of age-related dementias.
The study, based on MRI data from the Framingham Heart Study, observed consistent increases in brain volume and specific areas like the hippocampus over decades.
Despite the rise in total Alzheimer's cases due to an aging population, the percentage of people newly diagnosed with dementia has decreased since the 1970s.
External factors such as health, social, cultural, and educational influences, alongside genetics, may play a role in the observed increase in brain size.