Head Size May Indicate Risk of Dementia in Later Life, Scientists Say

*Islamabad:* Scientists have suggested that the size of a person’s head may indicate the risk of developing dementia later in life, potentially helping to predict whether an individual will be diagnosed with the debilitating neurological disease in old age.

According to experts, researchers in the US state of Texas analyzed nearly three decades of health data and post-mortem brain examinations of around 700 elderly nuns from across the United States. The nuns had similar lifestyles, incomes, living conditions, and educational backgrounds. Their ages ranged from 75 to 102 years, with an average age of 83.

All participants followed healthy diets, maintained strong social connections, and avoided harmful habits such as smoking and alcohol consumption. Despite these healthy lifestyles, around 17 percent of the nuns developed dementia in the later stages of their lives. All had agreed to donate their brains for research after death.

The study found that nuns with lower levels of education and smaller head circumferences were four times more likely to develop dementia compared to their peers who had higher educational attainment and larger head sizes. Researchers also observed that participants diagnosed with dementia had a relatively smaller hippocampus — the part of the brain responsible for memory and learning.

Scientists believe that a smaller head and brain size may mean fewer brain cells. As people age and brain cells are damaged, those with fewer neural reserves may have less capacity to protect against neurodegenerative diseases, increasing the likelihood of dementia symptoms appearing earlier or progressing more rapidly.

Low levels of education have long been associated with a higher risk of dementia, as learning strengthens connections between brain cells and encourages healthier lifestyle choices. Since most brain and head growth occurs early in life, particularly during childhood, the findings suggest that dementia prevention begins long before symptoms appear.

Researchers say the study highlights that brain health and dementia prevention are lifelong concerns, not issues limited only to old age.