Currently, there's no known way to prevent Alzheimer's disease, which affects more than 5 million Americans and is the sixth leading cause of death in the United States.
But a new study has identified what may be the earliest known biomarker associated with the risk of developing Alzheimer's. Indeed, this potential biomarker appears to be present in cerebral spinal fluid (CSF) at least a decade before signs of Alzheimer's first appear.
"If our initial findings can be replicated by other laboratories, the results will change the way we currently think about the causes of Alzheimer's disease," said Dr. Ramon Trullas, research professor at the CSIC Institute of Biomedical Research of Barcelona and lead author of the study that was published in Annals of Neurology, in a press release. "This discovery may enable us to search for more effective treatments that can be administered during the preclinical stage."
The identification of biomarkers is increasingly important. Finding an ideal biomarker could help distinguish Alzheimer's from other types of dementia. And this is key because treatment for these various forms of dementia could differ.
The CSIC researchers showed that a decrease in the amount of mitochondrial DNA (mtDNA) in CSF may indicate Alzheimer's; furthermore, there may be a real cause-effect relationship. The hypothesis is that decreased mtDNA levels in CSF reflect the diminished ability of mitochondria -- or the energy factories of the cell -- to power the brain's neurons, causing their death. The decrease in the concentration of mtDNA precedes the appearance of well-known biochemical Alzheimer's biomarkers (the Aβ1-42, t-tau, and p-tau proteins), suggesting that the progression of Alzheimer's starts earlier than previously thought and that mtDNA depletion may be one of the earliest signs of the disease.
In addition to helping with an investigation of the potential cause-effect relationship of mtDNA and Alzheimer's progression, the use of mtDNA as an indicator of Alzheimer's is better than the use of previous biochemical markers: the detection of this novel nucleic acid biomarker isn't hindered by the technical difficulties associated with other markers, Trullas said.
Trullas said he hopes that other laboratories and hospitals will successfully replicate the research results, confirming that reduced mtDNA levels should be investigated as a possible cause of Alzheimer's disease. By finding a way to block this degeneration, clinicians may be able to diagnose and treat Alzheimer's disease before symptoms appear, he added.
When it comes to Alzheimer's research, more good news emerged earlier this year when researchers at Utah State University discovered that the progression of decline in brain functioning among Alzheimer's patients may be dramatically slowed if caregivers simply change the patient's environment.