The human brain can get bigger over time. What the researchers discovered

Researchers believe there may be some truth to this fictional story, as a recent study has shown that our brains may actually get bigger over time.

Human brain PHOTO: Shutterstock

Scientists at UC Davis Health revealed that the brains of people born in the 1970s had 6.6% more volume and 15% more surface area than the brains of people born in the 1930s. The study was published in JAMA Neurology in March, writes

Genetics play a major role in determining brain size, but our findings indicate that external influences – such as health, social, cultural and educational factors – may also play a role.” Charles DeCarli, study author and professor emeritus of neurology at UC Davis, told ScienceDaily.

The researchers analyzed evidence from the Framingham Heart Study, a community-based study based in Framingham, Massachusetts, that has been running for about 75 years and now includes second and third generations of participants.

Between March 1999 and November 2019, scientists analyzed MRIs from people born between 1925 and 1968, with the average age of the participants being 57 years. They examined the brain scans of 3,226 participants (53% women, 47% men) and noticed a remarkable pattern.

Brain volume (or intracranial volume) increased slowly but steadily incrementally. In the 1930s, the average brain volume was 1,234 millimeters – but in the 1970s, the average was 1,321 millimeters; an increase of 6.6%. The cortical surface – the surface of the brain – also increased in size: from 2,056 square centimeters for those born in the 1930s to 2,104 square centimeters for those born in the 1970s.

The researchers also noticed an increase in size when it came to gray matter, white matter and the hippocampus – a part of the brain associated with learning and memory.

White matter is found in the deep tissues of the brain and contains nerve fibers that allow communication between different parts of the brain. It gets its name from the sheath (a myelin sheath) around the nerves, which is white.

Gray matter, on the other hand, is the outer layer of the brain and allows individuals to control movements, memory and emotions. It takes its name from a high concentration of neuronal cell bodies, which give the tissue a gray color.

The results are encouraging because they could mean a decline in age-related dementias such as Alzheimer's, the scientists noted.

“Larger brain structures, such as those seen in our study, may reflect improved brain development and better brain health,” DeCarli explained. “A larger brain structure represents greater brain reserve and may cushion the late-life effects of age-related brain diseases such as Alzheimer's and related dementias.”