Teenagers need iron to avoid impact on brain in later life
By Liz Lockhart
A lack of iron during teenage years can have a negative result on the brain later in life which could lead to disorders such as 
Alzheimer’s, according to recent research.
Levels of a protein (transferrin) that transports iron throughout the body and brain were measured by Paul Thompson, a professor at the University of California. The levels which were taken from adolescents were found to relate to differences in the brain’s structure when the adolescents reached young adulthood.
Thompson said ‘We found that healthy brain wiring in adults depended on having good iron levels in your teenage years. 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,’ Thompson said and added that iron and the proteins that transport it are critically important for brain function.
It is claimed that iron deficiency is the most common worldwide deficiency which causes low cognitive achievement in children. In later life, too much iron is associated with damage to the brain. Abnormally high concentrations of iron have been detected in Alzheimer’s patients, Huntington and Parkinson’s diseases.
According to the researchers, the body’s regulation of iron transportation to the brain is crucial as both a deficiency and an excess of iron can have a negative impact on brain function. If iron levels are low the liver produces more transferrin for increased transportation.
In order to find out whether brain structure in healthy adults was also dependent on transferrin levels, the researchers began by collecting brain MRI scans of 615 healthy twins and siblings. These participants had an average of 23. 574 of these participants were also scanned with ‘diffusion scan’, which maps the brain’s myelin connections and their strength. Myelin is a substance which coats the brain’s nerve axons and allows efficient conduction of nerve impulses. Iron has a key part in myelin production, according to the researchers.
The researchers had measured the participants’ blood transferrin levels some eight to 12 years before the current study. They wanted to determine whether iron availability at this developmentally important time of adolescence had an impact on the brain in later life. Transferrin levels had been assessed in the participants at the ages of 12, 14 and 16. Thompson said that by averaging these levels the researchers could then estimate the iron availability to the brain during adolescence.
Elevated transferrin levels are a common sign of poor iron levels in a person’s diet. The researchers found that the participants with an elevated level of transferrin had structural changes in brain regions which are vulnerable to neurodegeneration. When looking at the data of the twins in the study it was found that a common set of genes influences both transferrin levels and brain structure.
Thompson said ‘You wouldn’t think the iron in our diet would affect the brain so much in our teen years. But it turns out that it matters very much. Because myelin speeds your brain’s communications, and iron is vital for making myelin, poor iron levels in childhood erode your brain reserves which you need later in life to protect against aging and Alzheimer’s.’
‘This is remarkable as we were not studying iron-deficient people, just around 600 normal healthy people. It underscores the need for a balanced diet in the teenage years, when your brain’s command centre is still actively maturing,’ Thompson concluded.
Source: University of California, Los Angeles
