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Why Families Want to Understand Dementia’s Causes
When a parent or spouse is diagnosed with dementia, one of the first questions adult children ask is: “Could this happen to me?” It’s a natural question and an important one. Understanding what causes dementia and what the risk factors are can help families not only care better for their loved one today, but also make informed choices about their own brain health for tomorrow.
It’s also worth noting that understanding risk factors helps families put context around a diagnosis. Dementia isn’t anyone’s fault. It isn’t caused by doing something wrong. It arises from a complex interplay of genetics, age, health conditions, and lifestyle factors.
Age: The Biggest Risk Factor
The single greatest risk factor for dementia is age. While dementia is not a normal part of aging, it becomes significantly more common as we get older. According to the Alzheimer’s Association:
- Approximately 5% of people ages 65-74 have Alzheimer’s dementia
- Approximately 13.1% of people ages 75-84 have Alzheimer’s dementia
- Approximately 33.3% of people age 85 and older have Alzheimer’s dementia
| 1 in 3 | People over 85 are living with Alzheimer’s dementia. Age is the greatest risk factor, though dementia is not an inevitable part of aging. (Alzheimer’s Association, 2024) |
Genetic Risk Factors
Genetics play a role in dementia risk, but the picture is more nuanced than many families realize.
APOE-e4: The Most Significant Genetic Risk Factor
The gene most commonly associated with Alzheimer’s risk is APOE-e4. People who inherit one copy of APOE-e4 have approximately 3 times the average risk of developing Alzheimer’s. People who inherit two copies (one from each parent) have approximately 8-12 times the average risk.
However, and this is CRITICALLY important, having APOE-e4 does not guarantee you will develop Alzheimer’s. Many people with two copies of APOE-e4 never develop the disease. And many people with Alzheimer’s don’t have any copies of APOE-e4.
Early-Onset Familial Alzheimer’s Disease
A rare form of Alzheimer’s (less than 5% of cases) is caused by specific genetic mutations (in the APP, PSEN1, or PSEN2 genes) that are directly inherited. These mutations cause early-onset Alzheimer’s, before age 65, sometimes as early as one’s 30s or 40s. If you have a parent or sibling who developed Alzheimer’s before 60, genetic counseling may be appropriate.
Health Conditions That Increase Dementia Risk
Several medical conditions are associated with increased dementia risk:
- Cardiovascular disease: High blood pressure, high cholesterol, atrial fibrillation, and heart disease all affect brain blood flow and increase dementia risk
- Type 2 diabetes: Research shows a significant relationship between diabetes and dementia risk (see our detailed blog post on diabetes and dementia)
- Obesity: Mid-life obesity is associated with increased dementia risk
- Depression: Both a risk factor for and an early symptom of dementia
- Sleep apnea: Untreated sleep apnea is associated with increased cognitive decline
- Traumatic brain injury (TBI): Even a single moderate-to-severe TBI significantly increases lifetime dementia risk
- Hearing loss: Untreated significant hearing loss is one of the most actionable risk factors for dementia
Lifestyle Factors
This is where the news gets more encouraging, because several of the most significant dementia risk factors are modifiable:
- Physical inactivity: Regular exercise is one of the most powerful protective factors for brain health
- Smoking: Smokers have approximately twice the risk of developing Alzheimer’s compared to non-smokers
- Heavy alcohol use: Chronic heavy alcohol use is associated with significantly increased dementia risk
- Poor diet: Diets high in saturated fats and processed foods are associated with greater cognitive decline
- Social isolation: Chronic social isolation and loneliness are significant risk factors for cognitive decline
- Low education: Lower levels of formal education are associated with higher dementia risk (though this may be related to cognitive reserve)
The Role of Cognitive Reserve
Researchers have identified the concept of “cognitive reserve,” the brain’s resilience to damage. People with higher cognitive reserve, built through education, mentally stimulating work, learning new things throughout life, and social engagement, appear to be more resilient to the effects of brain changes associated with dementia. This doesn’t prevent dementia, but it may delay its onset or reduce its severity.
Can Dementia Be Prevented?
While there is currently no proven way to prevent dementia entirely, a 2020 Lancet Commission report identified 12 modifiable risk factors that, if addressed, could theoretically prevent or delay up to 40% of dementia cases worldwide. These include: less education, hearing loss, traumatic brain injury, hypertension, alcohol consumption, obesity, smoking, depression, physical inactivity, social isolation, air pollution, and diabetes.
The implications are powerful: the choices families, including yours, make today affect brain health tomorrow. This is as true for adult children monitoring their own health as it is for the aging parents they’re caring for.
Key Takeaways
- Families seek to understand dementia’s causes to make informed choices about their own health and care for loved ones.
- Age is the greatest risk factor for dementia, with the risk increasing significantly after 65 years old.
- Genetic factors, particularly the APOE-e4 gene, play a role but do not guarantee Alzheimer’s development.
- Modifiable lifestyle factors, like physical activity and dietary choices, can help reduce dementia risk.
- Understanding and addressing these risk factors can empower families to improve brain health for themselves and their loved ones.
What This Means for Ohio Families
For families in Warren County, Clermont County, and the surrounding Greater Cincinnati and Dayton, Ohio area, understanding these risk factors is actionable information. Ohio has excellent resources through the Ohio Department of Aging and local Area Agencies on Aging that support seniors in managing health conditions associated with dementia risk.
And for families who are already navigating a dementia diagnosis, Seniors Helping Seniors® Warren Clermont is here. Our professional in-home care supports not just the senior but the entire family, including Sandwich Generation adult children who are bearing enormous caregiving burdens while managing their own lives and their own health.
Visit https://www.shswarrenclermont.com to learn more or schedule a free consultation. We serve families throughout Milford, Loveland, Lebanon, Springboro, Centerville, Beavercreek, Kettering, and all surrounding communities in the Greater Cincinnati and Dayton, Ohio areas.
Sources: Alzheimer’s Association 2024 Alzheimer’s Disease Facts and Figures; Livingston G et al. “Dementia prevention, intervention, and care: 2020 report of the Lancet Commission.” The Lancet, 2020; National Institute on Aging.