Nearly 6 million Americans are living with Alzheimer’s, and despite the overwhelming presence and detrimental effect of the disease, researchers have not been able to accurately determine how it advances. Until now, that is.
A new study published in the peer-reviewed journal Science Advances was the first to use human data, rather than animal studies, to identify the cause of Alzheimer’s progression in the brain.
What causes Alzheimer’s to progress?
Before diving in, it’s helpful to know that there are two proteins involved in the cognitive decline of Alzheimer’s disease: amyloid-beta and tau. The buildup of these proteins is called aggregates, and they are responsible for memory loss, personality changes, and ultimately the killing of brain cells.
Until now, researchers thought the disease progressed by spreading from one region of the brain to another “in a way that’s similar to many cancers,” lead study author Georg Meisl, Ph.D., said in a news release.
By using brain samples from deceased Alzheimer’s patients and PET scans from living patients with varying progressions of the disease, researchers were able to track how tau aggregates actually develop. What they discovered is that rather than spreading over time, tau aggregates already exist in multiple regions of the brain at the onset. “So trying to stop the spread between regions will do little to slow the disease,” Meisl explains.
What does this mean for the treatment of Alzheimer’s?
While there’s still no treatment for the neurodegenerative disease, this study leads researchers one step closer to understanding it. “The key discovery is that stopping the replication of aggregates rather than their propagation is going to be more effective at the stages of the disease that we studied,” notes study co-author Tuomas Knowles, Ph.D.
In other good news, researchers found the replication of tau aggregates is actually quite slow—about five years on average. “Neurons are surprisingly good at stopping aggregates from forming,” says co-author and dementia researcher Sir David Klenerman, “but we need to find ways to make them even better if we’re going to develop an effective treatment.”
While there’s no treatment for Alzheimer’s disease, new technology is making more accurate research possible so scientists can get one step closer. In the meantime, people can take some preventive measures, such as these neurologists’ tips for combating cognitive decline at every age or potentially adding more amino acids to your diet.