Human Brains Getting Bigger: Good News for Dementia Risk?

While it's true that the average human brain has increased in size over the last few thousand years, the notion that this offers good news regarding dementia risk is not well-supported by scientific research. In fact, the relationship between brain size and dementia is not straightforward.

Brain size is a highly variable trait, and it is influenced by various factors such as genetics, nutrition, and environmental conditions. While some studies have reported an association between larger brain volume and reduced dementia risk, others have found no such correlation or even suggested a possible link to increased dementia risk in certain contexts.

In general, the development and progression of dementia are influenced by a complex interplay of genetic, environmental, and lifestyle factors, such as age, cardiovascular health, cognitive stimulation, and social engagement. While maintaining cognitive health and reducing the risk of dementia are important goals, there is no single factor, including brain size, that can definitively predict or guarantee protection against neurodegenerative diseases.

Research on dementia risk reduction primarily focuses on modifiable lifestyle factors and interventions, such as regular exercise, a healthy diet, cognitive training, and managing underlying health conditions. Promoting brain health and reducing the risk of dementia require a holistic approach that addresses multiple factors rather than relying solely on brain size as an indicator.