Alzheimer's may be an autoimmune disease, not brain disorder

A new theory about Alzheimer's disease suggests it may not be a brain disease, but a problem with the immune system. Researchers are exploring new ideas as traditional approaches have not led to effective treatments. In recent years, controversies have arisen in Alzheimer's research. A 2006 study linking the disease to a brain protein called beta-amyloid is now thought to have relied on false data. This has raised questions about treatments based on this research, such as aducanumab, which was approved by the FDA despite mixed evidence supporting its effectiveness. Scientists have focused on preventing beta-amyloid buildup in the brain, but this approach has not produced positive results. Researchers at the Krembil Brain Institute in Toronto now argue that Alzheimer's is primarily an autoimmune disorder. They believe beta-amyloid is a normal part of the brain's immune response that mistakenly attacks brain cells instead of protecting them. This misguided immune response can lead to brain cell damage and dementia. Current autoimmune treatments might not work for Alzheimer's, but the researchers believe targeting other immune pathways could lead to new therapies. Several alternative theories about Alzheimer's are gaining attention, including those related to energy production in brain cells, bacterial infections, and metal handling in the brain. As new ideas emerge, researchers aim to better understand Alzheimer's and find effective treatments for the millions affected worldwide.