A study has found that if a father has dementia, it is necessary for the daughter to check her brain once. If a father suffers from Alzheimer's disease, the risk increases that a mutation protein causing dementia accumulates in the child's brain. Previously, there was also research showing that children with a mother suffering from dementia have a high likelihood of having brain issues. However, while there is a correlation between the brain health status of parents and children, the causal relationship of a parent's dementia being inherited by the child has not yet been confirmed.
◇ Daughter with a father suffering from dementia, accumulation of tau protein in the brain
Professor Sylvia Villeneuve and her research team from McGill University in Canada noted on the 9th (local time) that "if a father suffers from Alzheimer's disease, there is a greater spread of tau protein in the child's brain, which increases the risk of developing Alzheimer's disease." The study results were published that same day in the international journal 'Neurology,' published by the American Academy of Neurology.
Alzheimer's disease is a degenerative brain disease that accounts for two-thirds of dementia patients. It is known to occur due to an abnormal accumulation of amyloid beta and tau proteins in the brain. Amyloid beta originally protects nerve cells, but when it detaches from the cells and forms clumps, it causes damage instead. Tau also functions as a connector that maintains the structure of nerve cells, but as it accumulates inside cells, it causes problems with cognitive function.
This study was conducted on 243 people with a family history of Alzheimer's disease who currently have no cognitive or memory problems. The average age was 68 years. The brains were imaged for 7 years while assessing cognitive function and memory. During this period, 71 individuals experienced mild cognitive impairment, the precursor to Alzheimer's disease.
The researchers found that there is more tau protein spread in the brains of individuals with a father suffering from Alzheimer's disease. Additionally, female participants had a greater accumulation of tau protein in their brains. Therefore, it can be said that the father's Alzheimer's disease is more related to the daughter's risk of development.
Professor Villeneuve stated, "We have proven the hypothesis that individuals with a father suffering from Alzheimer's have a greater accumulation of tau protein compared to those with a mother suffering from dementia," and added, "Understanding this vulnerability better may help design personalized treatments to prevent Alzheimer's disease."
Dr. Jordi Perez-Tur from the Biomedical Research Institute in Spain remarked about this study to the Science Media Centre, "In recent years, there have been several studies regarding the impact of parents with Alzheimer's disease on their children's risk of development, with conflicting conclusions based on gender," and stated, "While hidden biases may affect group analysis at specific points, this study tracked a single group for seven years."
Dr. Perez-Tur emphasized the significance of clarifying gender differences in disease research. He stated, "Considering the bodies of men and women as having the same structure is a harmful simplification throughout medical history, especially for women," and added, "Focusing on gender's impact on specific diseases enriches knowledge about diseases and leads to fairer science."
◇ Results also indicate that maternal dementia has a greater impact
There is a limitation that most of the people surveyed this time were white. While the correlation of greater tau protein spread in the brains of individuals with a father suffering from Alzheimer's was confirmed, the causal relationship of the father's dementia being inherited was not established.
Earlier, there were conflicting results indicating that a father's dementia relates less to the child's risk of development compared to the mother's dementia. A research team led by Professor Yang Hyun-sik at Harvard University reported last June in the Journal of the American Medical Association (JAMA) Neurology that individuals with a mother suffering from Alzheimer's had higher levels of amyloid beta protein.
The researchers analyzed 4,413 individuals aged 65 to 85 who currently show no cognitive function issues. They stated that these results suggest a trend of Alzheimer's disease being maternally inherited. Even if a father exhibits early memory impairment, the child's brain shows elevated levels of amyloid beta protein without any symptoms, while the mother's connection with high amyloid beta levels in her children was independent of the age of dementia onset.
Co-author Professor Reisa Sperling of Harvard University said, "The results of this study will soon be applicable in clinical settings," and added, "Maternally inherited Alzheimer's disease will be a significant factor in identifying patients who have not yet shown symptoms and in providing preventive therapies."
It has not yet been precisely determined whether a parent's dementia is inherited by the child. However, it has been revealed that there is a correlation with the child's brain health. Perhaps the stress of caring for a parent with dementia may have an influence. What is certain is that closely monitoring and taking preventive measures for parents' dementia can safeguard the health of their children.
References
Neurology (2025), DOI: https://doi.org/10.1212/WNL.0000000000213507
JAMA Neurology (2024), DOI: https://doi.org/10.1001/jamaneurol.2024.1763