Human brains may be getting larger over time, a fact that could bode well for the future of dementia care.
That’s according to a University of California, Davis study, published recently in JAMA Neurology. The study, which analyzed and compared MRIs of people born during the 1930s through the 1970s, found that people born in the ‘70s had 6.6% larger brain volumes and 15% larger brain surface than the previous generation born in the ‘30s.
“The decade someone is born appears to impact brain size and potentially long-term brain health,” said study author Charles DeCarli, who is a neurology professor, director of the UC Davis Alzheimer’s Disease Research Center. “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.”
Researchers found the brain volume steadily increased by decade, with participants in the 1930s averaging 1,234 milliliters and participants in the 1970s averaging 1,321 milliliters.
Larger brain size may correlate with a decreased risk of dementia over time. A previous study showed a 20% decrease in the incidence of dementia per decade since the 1970s, the researchers noted.
“Larger brain structures like those observed in our study may reflect improved brain development and improved brain health,” DeCarli stated.. “A larger brain structure represents a larger brain reserve and may buffer the late-life effects of age-related brain diseases like Alzheimer’s and related dementias.”
Other recent studies have shown that personality traits can be warning signs for dementia, including Neuroticism, low conscientiousness, and negative affect, while positivity and extraversion can have a positive effect for reducing dementia.
Other outside factors, including air pollution, alcohol and diabetes, could lead to developing Alzheimer’s as well, according to another study from the University of Oxford.