Women with Parkinson’s show a higher level of Alzheimer’s brain changes than men

Women with Parkinson’s may be more vulnerable to brain changes typically linked to Alzheimer’s than men. New research presented at the European Academy of Neurology Congress in June 2026 reveals that female patients carry a significantly higher amount of amyloid plaques in their brains after death compared to their male counterparts. Amyloid plaques are toxic protein clumps that build up between brain cells and are a primary feature of Alzheimer’s. Because Parkinson’s and Alzheimer’s frequently happen together in older adults, scientists from Mayo Clinic Arizona wanted to see if biological sex changes how these proteins build up. They looked at data from 230 brain autopsies of people who had confirmed Parkinson's. The findings showed a clear difference between the sexes. More than half of the women, nearly 57%, had a high amount of amyloid plaques in the brain, compared to just under 40% of the men. When the researchers scored the total plaque coverage, women scored an average of 6.5 out of 15, while men scored 4.9. The density of these plaques was also higher in women. What makes this finding particularly interesting is that the gap remained even after accounting for age and a major genetic risk factor called APOE Ɛ4. Even with those factors balanced out, women with Parkinson’s were still more than twice as likely as men to fall into the high plaque group. Surprisingly, this extra protein buildup did not seem to change how the women functioned during their lives. The researchers looked at the regular memory and thinking tests the participants took before they passed away, and women performed just as well as men. The rates of dementia were also similar between both groups. The lead author of the study, Dr Erika Driver-Dunckley, noted that a larger study might be needed to see if the higher plaque load causes subtle differences in memory that this project missed. While the exact biological reasons for the difference are still unknown, previous research shows that women without Parkinson’s also tend to develop more severe Alzheimer's brain changes than men. This latest discovery highlights a vital need to study how biological sex influences the way brain conditions develop, which could lead to more tailored treatments in the future.