Can Alzheimer’s Disease Be Prevented? 14 Modifiable Risk Factors That May Reduce Dementia Risk
Nearly Half of Dementia Risk May Be Modifiable—What I Share With Patients
When patients ask me about Alzheimer's disease, the question is often some version of:
"Is there anything I can actually do to prevent this?"
For many years, Alzheimer's disease was viewed largely through the lens of age and genetics. While those factors remain important, research over the past several decades has expanded our understanding of the lifestyle, health, and environmental factors that may influence cognitive decline.
According to the 2024 update from the Lancet Commission on Dementia Prevention, Intervention, and Care, approximately 45% of dementia cases worldwide may be attributable to modifiable risk factors across the lifespan.
That's a powerful statistic—but it's one I think is important to interpret thoughtfully.
Because this is not about eliminating risk or getting everything "right." It's about understanding how the environment your brain lives in over decades may influence its resilience and function as you age.
What "45% Modifiable Risk" Actually Means in Practice
This number comes from something called Population Attributable Fraction, which estimates how many cases of a condition might be reduced if certain risk factors were improved at a population level.
That's helpful from a public health perspective, but in practice, I'm looking at something slightly different:
How are these patterns showing up in the individual sitting in front of me?
Because this doesn't mean Alzheimer's disease is fully preventable, and it doesn't mean any one factor causes the disease. What it does mean is that there are meaningful ways to support brain health over time—and that those efforts are not insignificant.
The 14 Modifiable Risk Factors for Alzheimer's Disease and Dementia
The Lancet Commission organizes these risk factors across the lifespan, which is a helpful way to think about timing and opportunity.
Early Life and Cognitive Reserve
Lower levels of formal education are associated with increased dementia risk. This relates to cognitive reserve—the brain's ability to adapt and compensate over time.
While we can't go back and change early education, we can continue to build cognitive reserve through learning, engagement, and mental stimulation throughout life.
Midlife Risk Factors: Where I Often See the Greatest Opportunity
Midlife is often where I focus clinically because this is where many of the highest-impact, modifiable drivers emerge—particularly those tied to metabolic and vascular health.
These include:
- Hearing loss
- High blood pressure
- Obesity
- Traumatic brain injury
- Excess alcohol use
In practice, this is often where I see patterns begin to cluster—changes in blood sugar regulation, shifts in weight, rising blood pressure, or early signs of sensory decline. These are rarely isolated issues and often influence one another.
Later Life Risk Factors
In later life, we're often seeing the cumulative effects of long-term patterns.
These include:
- Smoking
- Depression
- Social isolation
- Physical inactivity
- Diabetes
- Air pollution exposure
- Vision impairment
- High LDL cholesterol
At this stage, the goal is less about perfection and more about supporting function, quality of life, and continued engagement.
The Common Thread: The Brain Reflects the Whole System
What stands out to me clinically is how much these risk factors overlap in their underlying physiology.
Many of them converge on a few key themes:
- Blood sugar regulation and insulin resistance
- Vascular health and circulation to the brain
- Chronic, low-grade inflammation
- Sensory input through hearing and vision
- Social and cognitive engagement
This is why I rarely think about brain health in isolation. In practice, we're often working on metabolic health, inflammation, cardiovascular function, sleep, and nervous system support—and the brain benefits as a result.
If you'd like to learn more about how I approach this in practice, you can learn more about my Well Aging & Senior Care services.
Alzheimer's Disease and Whole-Body Health
One reason these risk factors matter is that Alzheimer's disease is increasingly understood as a condition influenced by processes occurring throughout the body—not solely within the brain.
Many of the same factors that contribute to cardiovascular disease and metabolic dysfunction—including insulin resistance, vascular changes, chronic inflammation, and reduced physical activity—also appear to influence cognitive decline and dementia risk.
This is one reason I often focus on foundational aspects of health such as blood sugar regulation, cardiovascular health, sleep quality, physical activity, and inflammation. Supporting these systems benefits overall health and may also help support long-term brain health.
Why Hearing Loss is SO Important (and Often Overlooked)
One of the most surprising findings for many people is that hearing loss is consistently among the most significant modifiable risk factors for dementia.
In practice, this makes sense.
When hearing declines, the brain receives less input. Social interaction often decreases. The brain must work harder to interpret sound, increasing cognitive load.
Over time, this can contribute to withdrawal, fatigue, and reduced stimulation—all of which may influence cognitive health.
Addressing hearing changes early is one of the more straightforward—and often underutilized—interventions we have.
What This Looks Like in Practice
When I'm working with patients, I'm often looking at the broader patterns that influence brain health and healthy aging.
Instead, I'm looking at patterns such as:
- Blood sugar variability or insulin resistance
- Lipid patterns and cardiovascular risk
- Inflammatory markers
- Nutrient status
- Sleep quality
- Stress and nervous system load
Often, patients come in for concerns such as fatigue, weight changes, cardiovascular risk, or metabolic health challenges, and we begin addressing these patterns. Over time, we're also supporting many of the systems that influence how the brain ages.
What This Research Doesn't Fully Capture
The Lancet model provides one of the strongest evidence-based frameworks currently available for dementia prevention, but it doesn't address every factor that may influence cognitive health.
In practice, I may also consider areas such as:
- Gut health and the microbiome
- Environmental exposures, including mold and heavy metals
- Mitochondrial function
- Individual nutrient needs, including vitamin B12 and omega-3 fatty acids
Research in these areas continues to evolve. While they are not currently included among the established modifiable risk factors identified by the Lancet Commission, they may provide additional context in selected patients.
These considerations do not replace the foundational risk factors identified in the research—they simply add another layer of personalization.
A More Grounded Way to Think About Prevention
Rather than asking whether Alzheimer's disease can be prevented, I often guide patients toward a different question:
How can we support your brain's resilience over time?
Because the goal isn't perfect control—it's building capacity.
The capacity to adapt, repair, and maintain function even as the body changes.
Where I Typically Suggest Patients Start
For many people, this work becomes especially relevant in their 40s and 50s—when many of these patterns are still highly modifiable.
Foundational Areas to Support Brain Health
A few foundational areas I tend to focus on include:
- Stabilizing blood sugar
- Supporting cardiovascular health
- Maintaining regular physical activity
- Addressing hearing or vision changes
- Supporting sleep and mood
- Maintaining social connections
These are not quick fixes, but they are meaningful—and they add up over time.
Final Thoughts
The idea that nearly half of dementia risk may be modifiable is not a guarantee.
But it is an invitation.
An invitation to pay attention to the patterns that shape how the brain ages and to make steady, thoughtful changes that support long-term health.
Because in practice, it's rarely one big intervention that makes the difference.
It's what is done consistently, over time.
Concerned About Brain Health?
If you're concerned about cognitive decline, have a family history of dementia, or want to identify modifiable factors that may influence healthy aging, a comprehensive evaluation can help uncover opportunities to support long-term brain health before significant symptoms develop.
Learn more about my Well Aging & Senior Care services to explore a personalized approach to healthy aging, cognitive wellness, and long-term vitality.
References
- Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet Commission. The Lancet. 2024.
- Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. The Lancet. 2020;396(10248):413-446.
- Alzheimer's Research UK. Dementia risk factors and prevention resources.
- Alzheimer's Disease International. Global dementia reports and statistics.
Photo by David Matos on Unsplash
About the Author
Dr. Sarah Giardenelli, ND, MSOM, LAc, is a naturopathic doctor and licensed acupuncturist in Leesburg, Virginia. She has a special interest in healthy aging, metabolic health, hormone balance, cognitive wellness, and chronic inflammatory conditions. Through her work at Collective Health Center, she helps patients identify modifiable factors that influence long-term health, resilience, and quality of life.
She combines naturopathic and East Asian medicine with evidence-informed care, focusing on personalized strategies that support healthy aging and long-term well-being.