Mayo Clinic Mar 4 2026 Alzheimer's-related brain changes progressed up to 20 times faster in women who also had abnormal levels of a Parkinson's-related protein, according to a Mayo Clinic study published in JAMA Network Open. The same pattern was not observed in men. The findings suggest that when alpha-synuclein - a protein linked to Parkinson's disease - accumulates alongside Alzheimer's pathology, it may drive faster disease progression in women. That interaction could help explain a long-