Study finds human brains growing larger, potentially lowering dementia risk

Recent research suggests that human brains are increasing in size, offering promising implications for reducing the risk of dementia. Picture:

Recent research suggests that human brains are increasing in size, offering promising implications for reducing the risk of dementia. Picture:

Published May 9, 2024


A study conducted by researchers from the University of California has found a remarkable trend — human brains are expanding in size, potentially heralding positive developments in the fight against dementia and other brain diseases.

The study drew upon data from the well established Framingham Heart Study (FHS), which commenced in 1948 and has persisted for 75 years, encompassing individuals born from the 1930s through the 1970s.

Originally designed to investigate cardiovascular diseases, the research honed in on MRI results from over 3,200 participants, spanning various generations.

Published in the journal JAMA Neurology, the University of California study documented noteworthy increases in cerebral measures over successive generations.

Specifically, individuals born in the 1970s exhibited a brain volume approximately 6.6% larger than those born in the 1930s, with corresponding enhancements in the cortical surface area, white matter, grey matter, and hippocampus volumes.

Lead author Charles DeCarli, a distinguished professor of neurology at the University of California, underscored the significance of these findings.

“The decade someone is born appears to impact brain size and potentially long-term brain health,” DeCarli said in a statement.

“Genetics plays a major role in determining brain size, but our findings indicate external influences — such as health, social, cultural and educational factors — may also play a role.”

Despite advancements in understanding dementia risk factors, the World Health Organization (WHO) reports that over 55 million people worldwide currently suffer from dementia, predominantly Alzheimer's disease cases.

While the study's insights are promising, researchers emphasise the need for additional investigations, particularly within more diverse cohorts, as the current study predominantly comprises white participants.

According to Dementia SA, South Africa’s growing elderly population, poor socio-economic conditions and high HIV/AIDS infection rate makes the country’s population especially vulnerable to the disease.

The organisation estimates that one in every three persons with HIV/Aids will develop dementia.

With dementia being largely misunderstood and undiagnosed in South Africa, appropriate levels of care and support are still lacking, especially within public health, where it would be needed the most.

While brain size does appear to be a contributing factor, the study implores that addressing dementia risk comprehensively necessitates a multifaceted approach, including physical activity and a balanced diet.