New research from the University of Southern California (USC) suggests that an Alzheimer’s diagnosis in one sibling can lead to a shorter lifespan in other family members, even those without dementia.
This study, published in Alzheimer’s & Dementia, sheds light on how a combination of genetics and environmental factors influences the longevity of individuals within the same family.
The research, based on data from the Swedish Twin Registry, aimed to understand the impact of Alzheimer’s disease on the lifespan of siblings, both those with and without dementia.
The study was conducted over nearly 40 years and involved a cohort of more than 45,000 Swedish twins, including both identical and fraternal pairs.
Key findings from the study include:
Shared Genes and Environment: Identical twins share 100% of their genotype, while fraternal twins (and full siblings) share about 50%. Most twins, regardless of their type, generally grow up in the same environment, which includes factors like pollution exposure, diet, education, and physical activity.
Impact on Lifespan: The research confirmed that receiving a dementia diagnosis does affect an individual’s lifespan, with people living an average of seven years after being diagnosed with dementia. This finding aligns with previous studies.
Identical Twins: In pairs of identical twins, if one twin is diagnosed with dementia, both twins tend to have similarly shortened life expectancies. The shared genetics play a significant role in this outcome.
Fraternal Twins: In pairs of fraternal twins, if one twin is diagnosed with dementia, the twin without dementia also experiences a slightly shortened lifespan compared to someone without a sibling with dementia.
This suggests that dementia is not the sole factor contributing to a shorter lifespan; instead, it’s a combination of shared genes and environmental factors.
Importance of Early Life Factors: The study highlights the significance of early life factors in influencing later-life health. Factors like a healthy diet, exercise, and education during childhood can contribute to a lower risk of developing dementia and other health conditions in the future.
This research has practical implications for families dealing with Alzheimer’s disease. It provides insights into the shared factors that impact the lifespan of siblings, both those affected by dementia and those who are not.
Understanding these factors can help families make informed decisions about financial and end-of-life planning when facing this challenging disease.
The study’s lead author, Jung Yun Jang, emphasized the importance of early-life interventions, saying, “What happens early in the life course is really important.
You may not be able to change that for yourself, but it does seem like the message to parents is, make sure your kid eats healthy, make sure your kid gets exercise, make sure your kid gets an education.
You’re actually contributing to giving that kid a lower chance of developing dementia 75 years later.”
This research underscores the complex interplay of genetics and environment in determining health outcomes, emphasizing the need for a holistic approach to healthcare and disease prevention.
If you care about Alzheimer’s, please read studies about the likely cause of Alzheimer’s disease and new non-drug treatment that could help prevent Alzheimer’s.
For more information about brain health, please see recent studies about diet that may help prevent Alzheimer’s, and results showing some dementia cases could be prevented by changing these 12 things.
The research findings can be found in Alzheimer’s & Dementia.
Copyright © 2023 Knowridge Science Report. All rights reserved.
