AmericaRecent research shows that people’s brains get larger over time, which is a good sign that Alzheimer’s conditions are generally improving.
The study was conducted by UC Davis Health Medical Center, published in the journal JAMA Neurology in March, and was reported by the media on April 26. Scientists say the brains of people born in the 1970s and later have 6.6% more mass and 15% more surface area than the brains of people born in the 1930s.
Charles DeCarli, professor of neurology at UC Davis Health and study author, said genetics plays an important role in determining brain size. However, external factors, such as health, society, culture and education, also partly influence.
To do the work, experts looked at evidence from the Framingham Heart Study, a larger study that took place over 75 years. They analyzed magnetic resonance imaging (MRI) images of more than 3,200 people born between 1925 and 1968, with an average age of 57. The images were taken periodically from March 1999 to November 2019.
As a result, brain size (or intracranial volume) gradually and steadily increases. In the 1930s, the average brain size was 1,200 mm, by the 1970s the average was 1,320 mm, an increase of 6.6%. The surface area of the cerebral cortex also increased, from 2,000 cm2 to 2,100 m2.
The researchers also found increases in gray matter, white matter, and the hippocampus. These are the parts of the brain involved in memory and learning. White matter is found in the deep tissues of the brain, containing nerve fibers that allow different parts of the brain to communicate. Gray matter is the outer layer of the brain, allowing individuals to control movement, memory, and emotions.
Experts consider these results to be encouraging, showing that age-related memory loss, such as Alzheimer’s, is improving in the general population.
“Large brain structures represent better information storage, lessening the effects of aging over time,” DeCarli explains.