Are You Older Than You Think?
You may be 75 on paper—but how old are you really?
New research suggests your biological age—not your calendar age—might be a better predictor of dementia. And depending on your genetics, this difference could mean the difference between staying sharp and facing memory decline.
In a groundbreaking study published in Neurology, scientists found that biological age acceleration—when your body is aging faster than your actual age—correlates strongly with the development of dementia.
Even more striking? For people who carry the ApoE4 gene, a well-known genetic risk factor for Alzheimer’s, this biological aging effect multiplies dramatically.
Let’s unpack what that means—and what you can do about it.
We all know aging brings changes—wrinkles, gray hair, maybe a creaky joint or two. But beneath the surface, your biological age tells a more detailed story.
Unlike your birthday, biological age is based on markers inside your body: things like inflammation levels, cholesterol, white blood cell count, and other lab values. Scientists have developed various “aging clocks” to estimate this internal aging process.
In the Neurology study, researchers looked at 280,000 people from the UK Biobank—a massive health data registry. None of these individuals had dementia at the beginning of the study, but over 10 years, nearly 5,000 developed it.
What separated the higher-risk group? Not just age—but how fast they were biologically aging.
Using two different biological age “clocks,” the researchers calculated how far ahead or behind someone’s biological age was compared to their actual age. Every year of acceleration added about 1% more risk for dementia.
For example, if you’re 70 but your biological age is 78, your dementia risk may be 8% higher than someone aging “on schedule.”
Now here’s where it gets even more compelling.
The study found that people with the ApoE4 gene—present in about 25% of the population and a known risk factor for Alzheimer’s—saw a fourfold increase in dementia risk if their biological age was accelerated.
In other words, your internal clock could interact with your genetic makeup in powerful ways.
This raises a critical point for your family: If you or a loved one carries the ApoE4 gene, paying attention to biological aging may offer a window for early action.
Here’s the good news: While we can’t change our genes or our birthdays, we can influence our biological age.
The study suggested that brain volume—a measure of how much your brain has shrunk—might explain some of the link between faster aging and dementia. But other factors play a role, too:
- Chronic inflammation
- High blood sugar or cholesterol
- Poor diet and lack of exercise
- Stress and sleep deprivation
When these systems break down, your cells show signs of stress—signs that the body reads as “old,” regardless of your age in years.
Researchers admit that calculating biological age isn’t perfect. Different formulas exist, and they don’t always agree.
Still, there’s something motivating about seeing a number tied to your lifestyle—not just the passage of time. And tools like the PhenoAge calculator (available online) give you a rough estimate using standard lab results like C-reactive protein and blood sugar.
Here’s the kicker: Small improvements can make a difference.
The study’s lead scientist noted that just lowering your inflammation marker (CRP) by half a point could “make you a year younger” biologically.
That might not sound like much—but if each year of accelerated aging raises dementia risk, every year you reclaim could count.
This study doesn’t claim that biological aging causes dementia—but it certainly strengthens the link.
And while more research is needed, especially to test whether slowing biological aging can reduce dementia risk, the message is clear: What you do now matters.
Eating better, reducing stress, exercising, getting good sleep—it’s not just about living longer. It may help you stay sharper, too.
So yes, age is still the biggest risk factor for dementia. But maybe the better question isn’t how old you are… but how well you’re aging.
To healthier years ahead,
Rachel Mace
Managing Editorial Director, e-Alert
with contributions from the research team
