Biological age and dementia: what the King’s College study found
Quick answer
Biological age is how well your cells, blood vessels and immune system are actually working, rather than how many birthdays you have had. A King’s College London study found people whose biological age was older than their chronological age were far more likely to develop dementia, particularly vascular dementia, and often at a younger age.
A fascinating study from King’s College London has highlighted something functional medicine practitioners have been discussing for years: your body can age biologically faster than the number of birthdays you have celebrated. More importantly, this accelerated aging significantly increases your risk of dementia.
The study used a blood-based “aging clock” to estimate biological age via metabolites in blood plasma. Researchers discovered that people whose biological age was older than their chronological age were far more likely to develop dementia—particularly vascular dementia—and often at a much younger age.
From a functional medicine perspective, this reinforces a core principle: aging is not just about time passing. It is a modifiable process deeply influenced by inflammation, metabolic health, toxicity, and lifestyle.
Chronological vs. Biological Age
Two people can both be 60 years old chronologically, yet one might have the cellular resilience of a 40-year-old while the other shows signs of advanced degeneration. Biological age reflects how your cells, tissues, blood vessels, and immune system are actually functioning.
In functional medicine, we often see patients who are biologically “older” long before a conventional diagnosis emerges. This sneaky, accelerated aging often shows up as chronic fatigue, insulin resistance, or mild brain fog years before major symptoms manifest.
Why Vascular Health is Brain Health
The study found that individuals with advanced biological aging had a 60% higher likelihood of developing vascular dementia.
Physiologically, this makes perfect sense. The brain depends entirely on healthy blood flow, oxygen delivery, and stable glucose regulation. Anything that damages your blood vessels damages your brain. Poor cardiovascular health, chronic inflammation, and oxidative stress all erode brain resilience over time.
The APOE4 Gene Is Not Destiny
The researchers also looked at the APOE4 (a version of the apolipoprotein E gene) gene, a well-known genetic risk factor for Alzheimer’s. Individuals carrying two APOE4 variants alongside accelerated biological aging were up to ten times more likely to develop dementia.
However, the most empowering takeaway is that biological aging can be slowed down. Genes may load the gun, but lifestyle pulls the trigger. The researchers emphasized that nearly 70% of dementia cases worldwide may be preventable or delayed through lifestyle interventions.
The 4 Pillars of Brain Longevity
To protect the brain, functional medicine looks beyond the skull and investigates the whole body:
- Blood Sugar & Insulin Sensitivity: Chronic high glucose damages blood vessels and impairs brain cells (often called “Type 3 Diabetes”).
- Inflammation & Cellular Stress: Driven by poor diet, gut issues, stress, and environmental toxins, chronic inflammation acts as a massive accelerator of cellular aging.
- The Gut-Brain Axis: Your microbiome regulates inflammation and protects blood-brain barrier integrity.
- Sleep & Brain Detox: During deep sleep, the brain activates its “glymphatic system” to wash away metabolic waste and toxic proteins associated with neurodegeneration.
Prevention is the Future
We don’t have to wait for memory problems to develop. By optimizing your metabolism, reducing your toxic load, and supporting your gut and sleep today, you can directly influence how fast your cells age.
The goal isn’t just to add years to your life—it’s to protect your cognition, vitality, and independence for as long as possible.
Common questions
What is biological age?
Biological age reflects how your cells, tissues, blood vessels and immune system are actually functioning, not the number of years you have lived. For example, two 60-year-olds can differ: one may have the cellular resilience of a 40-year-old, while the other shows signs of advanced degeneration.
Does the APOE4 gene mean I will get dementia?
APOE4 is a well-known genetic risk factor for Alzheimer’s, but we do not see it as destiny. In the King’s College London study, people with two APOE4 variants and accelerated biological ageing were up to ten times more likely to develop dementia. We stress that biological ageing can be slowed.
Can you slow biological ageing to lower dementia risk?
We say biological ageing can be slowed. The King’s College London researchers emphasised that nearly 70% of dementia cases worldwide may be preventable or delayed through lifestyle interventions. We highlight blood sugar and insulin sensitivity, inflammation and cellular stress, the gut-brain axis, and sleep as key areas.
This article is for general information and isn’t a substitute for personal medical advice. Please speak to your GP (family doctor) or a qualified practitioner before making changes to medication or treatment.