High levels of iron could be associated with an increased risk of developing Alzheimer's disease. The results of a new study, published in Nature Communications, suggest it may be useful to measure iron levels in the brain in order to pinpoint who is at risk of developing the disease. The findings may also inspire future studies to investigate whether a drug that lowers iron levels could slow the disease's progression.
Researchers from the University of Melbourne studied the brains of 144 individuals with mild cognitive impairment (MCI), 67 with Alzheimer's disease and 91 healthy individuals. Over a seven-year period, they measured the levels of ferritin—a protein that stores iron—in their cerebrospinal fluid and carried out regular MRI scans and cognitive tests.
"We think that iron is contributing to the disease progression of Alzheimer's disease," lead author Dr Scott Ayton, told ABC Science.
The study found that individuals with higher levels of ferritin had quicker declines in cognitive abilities and were diagnosed with Alzheimer's at an earlier age. Patients with MCI who had higher levels of ferritin also developed Alzheimer's disease faster. The researchers also found a link between ferritin and a gene strongly associated with Alzheimer's disease known as ApoE4.
Ayton tells ABC Science that there is enough “strong evidence” to carry out a clinical trial where the iron content in the brain is lowered to see if it would “impart a cognitive benefit.” When speaking to New Scientist, he points to a 24-year-old study of a drug that halved the rate of Alzheimer's cognitive decline. The drug—called deferiprone—was eventually sidelined, but Ayton says, "Perhaps it's time to refocus the field on looking at iron as a target."
But Dr. James Pickett, head of research at Alzheimer's Society, warned in a statement that the “biggest mistake we could make would be to take these results as meaning that a test for conversion from mild cognitive impairment to Alzheimer's disease is around the corner. It's not clear enough from this study whether iron levels could be used to predict this conversion with enough accuracy and we can't draw any conclusions about whether we might be able to use iron as a target for future treatments."