Scientists are discovering that diseases affecting the brain do not always affect men and women in exactly the same way.
Parkinson’s disease is a long-term brain disorder that mainly affects movement. People with Parkinson’s may develop shaking, stiffness, slow movement, and balance problems. As the disease progresses, many people also experience changes in memory and thinking. Alzheimer’s disease is another common brain disorder in older adults.
It gradually damages memory, thinking, and the ability to carry out everyday tasks. Doctors have known for many years that some people with Parkinson’s disease also develop changes in the brain that are usually linked with Alzheimer’s disease, but they have not fully understood whether men and women are affected in the same way.
A new study presented at the European Academy of Neurology (EAN) Congress 2026 suggests that women with Parkinson’s disease may be more likely than men to develop Alzheimer’s-related changes in the brain.
The research was carried out by scientists at Mayo Clinic Arizona. They examined information from 230 people whose Parkinson’s disease had been confirmed after death through detailed brain examinations.
All participants had taken part in the Arizona Study of Aging and Neurodegenerative Disorders and the Brain and Body Donation Program. During their lives, they received yearly medical and memory assessments. After death, researchers carefully examined their brain tissue.
The scientists focused on amyloid plaques, one of the main signs of Alzheimer’s disease. Amyloid plaques are sticky clumps of protein that build up between brain cells. Although researchers are still studying their exact role, these plaques are considered one of the hallmark features of Alzheimer’s disease.
The results showed that women with Parkinson’s disease had significantly more amyloid plaques than men. More than half of the women had a high plaque burden, compared with about four in ten men.
Even after taking into account age and the APOE ε4 gene, which greatly increases the risk of Alzheimer’s disease, women remained more than twice as likely to have heavy amyloid plaque buildup.
Lead researcher Dr. Erika Driver-Dunckley said the findings suggest that women may be biologically more vulnerable to Alzheimer’s-related brain changes when they also have Parkinson’s disease.
One surprising finding was that the greater plaque buildup did not translate into obvious differences in memory tests or Alzheimer’s dementia diagnoses. Men and women performed similarly during cognitive testing, despite women showing more Alzheimer’s-related brain pathology.
The researchers believe there are several possible explanations. One possibility is that the study was not large enough to detect subtle differences in memory and thinking.
Another possibility is that some women may have greater cognitive reserve, allowing the brain to continue functioning normally despite more disease-related changes. More research is needed before scientists can answer these questions.
The findings are consistent with earlier Alzheimer’s research showing that women without Parkinson’s disease also tend to develop more severe Alzheimer’s-related brain changes than men. This raises the possibility that women may have a biological susceptibility that becomes even more important when Parkinson’s disease is also present.
Understanding these differences could eventually improve patient care. If future studies confirm the findings, doctors may be able to identify women with Parkinson’s disease who have a higher risk of Alzheimer’s-related changes and monitor their memory more closely.
The research may also guide the development of new treatments aimed at slowing both Parkinson’s disease and Alzheimer’s disease.
This study provides important new evidence because it examined brains that were confirmed to have Parkinson’s disease through autopsy, making the diagnosis highly reliable. However, the research was presented at the EAN Congress 2026 and has not yet been published in a peer-reviewed journal, so the findings should be viewed as preliminary until they are independently confirmed.
The study also cannot explain why women developed more amyloid plaques or prove that these plaques will always lead to worse memory. Larger studies involving more diverse populations will be needed.
Even so, the findings highlight the importance of studying sex differences in brain diseases and could eventually help doctors develop more personalized approaches for preventing cognitive decline in people living with Parkinson’s disease.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
For more information about brain health, please see recent studies that blueberry supplements may prevent cognitive decline, and results showing Plant-based diets could protect cognitive health from air pollution.
Source: Mayo Clinic Arizona.
