"We found that healthy brain wiring in adults depended on having good iron levels in your teenage years," said Thompson, a member of UCLA's Laboratory of Neuro Imaging. "This connection was a lot stronger than we expected, especially as we were looking at people who were young and healthy none of them would be considered iron-deficient.
"We also found a connection with a gene that explains why this is so. The gene itself seems to affect brain wiring, which was a big surprise," he said.
To assess brain volume and integrity, Thompson's team collected brain MRI scans on 615 healthy young-adult twins and siblings, who had an average age of 23. Of these subjects, 574 were also scanned with a type of MRI called a "diffusion scan," which maps the brain's myelin connections and their strength, or integrity. Myelin is the fatty sheath that coats the brain's nerve axons, allowing for efficient conduction of nerve impulses, and iron plays a key role in myelin production.
Eight to 12 years before the current imaging study, researchers measured the subjects' blood transferrin levels. They hoped to determine whether iron availability in the developmentally crucial period of adolescence impacted the organization of the brain later in life.
"Adolescence is a period of high vulnerability to brain insults, and the brain is still very actively developing," Thompson said.
By averaging the subjects' transferrin levels, which had been assessed repeatedly at 12, 14 and 16 years of age the researchers estimated iron availability to the brain during adolescence, he said.
The team discovered that subjects who had elevated transferrin levels a common sign of poor iron levels in a person's diet had structural changes in brain regions that are vulnerable to neurodegeneration. And further analyses of the twins in the study revealed that a common set of genes influences both transferrin l
|Contact: Mark Wheeler|
University of California - Los Angeles