2024-04-06 14:56:55
The study examined the brains of more than 3,000 Americans between the ages of 55 and 65 and found that in the 20th century, People born in the 1980s have a total brain volume of 6.6 percent. higher than those born in the 40s.
Representatives of Generation X (people born between 1961 and 1981) also had almost 8 percent. a larger volume of white matter and almost 15 percent. greater surface area of gray matter than representatives of the silent generation (people born between 1928 and 1945).
One particular part of the brain, called the hippocampus, which plays an important role in memory and learning, expanded by 5.7 percent over several consecutive generations.
This was even after controlling for other factors such as height, age and gender.
“Decade of birth seems to influence brain size and possible long-term brain health,” explains neuroscientist Charles DeCarli from the University of California, Davis (USA), who led the study.
“Genetics play an important role in determining brain size, but our findings suggest that external factors – such as health, social, cultural and educational factors – may also play a role.”
Dementia currently affects tens of millions of people worldwide, and with an aging population, the number of diagnoses is set to triple over the next three decades.
But there are some hopeful predictions: Over the past three decades, the incidence of dementia in the United States and Europe has declined by about 13 percent per decade.
The absolute risk of dementia appears to be decreasing in younger generations, possibly due to healthier lifestyles and education.
Dementia is characterized by thinning of the brain’s gray matter, which plays an important role in memory, learning and thinking, among many other cognitive processes.
Since diseased brains gradually shrink over time, it stands to reason that a larger brain volume may help protect against age-related changes.
Really studies have shownthat Alzheimer’s patients with larger heads have better cognitive abilities, supporting the so-called “brain reserve hypothesis”.
To find out if brain size can explain the lower incidence of dementia in younger generations, Ch. deCarli and his colleagues used the Cardiovascular Disease Study, which has been conducted in Framingham since 1948. Framingham Heart Study) data.
When the study participants turned 55-65 years old – which happened between 1999 and 2019. – they underwent brain magnetic resonance imaging. This data was published only in 2023. in October
Reviewing the results, Ch. deCarli and colleagues showed that the brain volume of the younger generation is larger both overall and regionally.
The team also compared individuals born in the 1940s and 1980s. They repeated the analysis among 1,145 age-matched adults born in the 1950s and 1960s.
The research findings again revealed a steady and consistent increase in brain volume decade after decade, an effect the researchers say is small for an individual but “likely to be significant at the population level.”
“The larger brain structures observed in our study may reflect better brain development and better brain health,” Ch suggests. DeCarli. “A larger brain structure means more brain reserve and can mitigate the effects of age-related brain diseases, such as Alzheimer’s disease and related dementias, in late life.”
However, neuroscientists do not always agree on whether brain volume is a valid indicator of brain reserve. Some studies showed no relationship between memory performance and brain volume over time.
After all, when it comes to brain function, size isn’t everything. A big brain doesn’t necessarily make you smarter. However, it can be a good brain reserve that mitigates the symptoms of age-related decline in brain function.
It is important to note that regular physical exercises are related with greater brain volume in the areas of memory and learning. Meanwhile, poor nutrition, alcohol consumption and social isolation has the opposite effect.
“Larger brain structure, which may reflect better brain development and brain health, is at least one manifestation of improved brain reserve that could moderate the effects of late-life disease on sporadic dementia,” the study says.
The study is published in JAMA Neurology.
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2024-04-06 14:56:55