Part 2: How much do different lifestyle factors influence dementia risk?
September 5 2024 | Last Updated: Feb 4 2026
This content is provided for general education and information only. It does not provide individualized medical advice, diagnosis, or treatment, and does not establish a doctor–patient relationship. Always seek the advice of your own physician or qualified healthcare provider regarding personal medical decisions.
Table of Contents
“Although behaviour change is difficult… individuals have a huge potential to reduce their dementia risk.”
In the second half of our two-part series on determining your risk of future dementia, we discuss the impact of lifestyle changes.
In 2024, a group of internationally renowned dementia experts found 14 modifiable risk factors for dementia that together account for at least 45% of dementia cases in the world.
In this article we discuss the impact of these lifestyle changes, reviewing the research and providing an estimate on the level of personal risk for each factor.
For help on figuring out your baseline risk, read Part 1.
What are the risk factors?
The 14 risk factors identified by the experts are shown below:
Based on Aldora’s clinical experience, we would also add the following as potential risk factors for dementia:
Poor sleep, including untreated sleep apnea
Certain medications with memory side effects
Anxiety / stress
Negative mindset / lack of purpose
Poor nutrition
We don’t have exact percentages of risk increase for these additional risk factors. However, in a recent Canadian study that included sleep as a risk factor, up to 68% of dementia cases were preventable.
For the purposes of this article, we just focus on the risk factors in the diagram above.
How big is the effect?
To figure out how much a certain risk factor (like smoking or high blood pressure) increases your chances of getting dementia, we use something called “relative risk.”
You’ve probably seen this in health headlines — for example:
“Shingles vaccine lowers dementia risk by 20%”. That “20%” is the relative risk.
Can relative risk be misleading? Yes. Relative risk tells you how much a factor changes your risk - not the final risk itself. That’s what we’ll show you how to do next.
The diagram below shows the relative risk for the 14 different risk factors in the previous diagram.
How do I read the chart? Just take the number after the decimal and add a 0. For example, a relative risk of 1.3 = 30% more risk. Likewise, a relative risk of 1.6 means a 60% increased risk. Easy.
What is the estimated effect on me?
To figure out your personal risk estimate, you need two numbers:
Your baseline risk (explained in Part 1)
The relative risk for any factor you have (outlined in red in the chart above)
For those who want to understand how the math works, keep reading. If you’d rather skip straight to the final estimate, scroll to the summary table below.
The math:
Step 1: What’s Your Baseline Risk?
Most people have a 10% lifetime risk of developing dementia.
If you have a genetic risk, like a family history or certain genes (e.g. APOE-e4), that number can be closer to 20%.
Step 2: Multiply by the Relative Risk
Use this simple formula: Baseline risk (as a decimal) × Relative risk = New personal risk
Example:
If you smoke, your relative risk is about 1.3.
If your baseline risk is 10% (or 0.1 in decimal form):
0.1 × 1.3 = 0.13
Which means your new lifetime risk becomes 13%.
In other words - 30% of 10% is 3% - add that to the 10% for the new risk estimate.
The Summary:
The following table assumes a baseline lifetime risk of 10% for the general population, and 20% for people with a family history of dementia.
Remember: risk of dementia = risk of brain balance shifting too far to the side of damage relative to strength.
Based on research by Livingston et al, Lancet, 2024
Important Notes:
These numbers are estimates, not guarantees.
Some risk factors interact with each other, so they can’t be added together in a simple way. For example, hearing loss can lead to social isolation, which in turn may reduce hobbies and mood, all of which affect dementia risk.
However, in general if you have more than one risk factor, the risks accumulate and can make your total risk higher.
More personalized tools and risk calculators are currently in development. Until then, this simple approach gives you a starting point to understand how your lifestyle may shape your brain health tomorrow.
This also helps you weigh the risks of individual daily habits - you can choose for yourself whether something is worth the risk. No one can tell you what’s right and wrong when it comes to living your life - what we can tell you is an estimate of how it might influence your brain health over a lifetime.
Aldora’s guiding principles to dementia risk
Let’s put the math into practical action statements.
Based on experience with thousands of real-life dementia cases, the following principles help to estimate your risk:
Focus on your personal risk factors with the greatest risk - and make sure those are well managed (find focus with the lifestyle quiz).
The severity of the risk factor matters - drinking 20 beers a week is worse than drinking 4.
True longevity means protecting your whole body, including your brain. Modern medicine can help you live longer, but without active dementia prevention many people live longer with memory loss.
The goal: aim to have no more than 2-3 risk factors at any one time especially as you age, and if you have the APOE ε4 gene, keep your risk factors to 1 or less.
Remember: “risk” sounds scary, until you realize understanding it is an opportunity for a longer life with more independence at any age.
You can remove the risk if you do something about it. Using hearing aids, taking medications for high blood pressure, going for a walk, cutting down on alcohol… all of these things can help keep your brain balanced.
If you want to learn more about how to address each of the 18 risk factors, join the Pathway.
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Key References:
Livingston G et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet, 2024; 404:572 - 628.
Why trust Aldora?
Aldora Health was founded by a Canadian physician specializing in cognitive health and dementia prevention. Content is informed by clinical experience, large population studies, and current prevention research, and is designed to support informed, thoughtful health decisions over time.
Disclaimer: The content on Aldora Health is for educational and informational purposes only and is not intended to substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. For more read our Terms of Use.