New research shows that how old your blood looks might matter as much as your birthday when it comes to dementia risk, with a metabolite-based measure called MileAge linked to a higher chance of developing several forms of dementia and interacting strongly with the APOE gene.
Scientists reviewed blood-based metabolite profiles from more than 223,000 people in a large UK dataset, looking for patterns that signal biological aging rather than calendar years. These metabolites reflect fat processing, inflammation and energy use, and the team used that mix to estimate each participant’s metabolic or biological age. They then compared that metabolite-predicted age to actual age to create MileAge delta, a simple gap score where positive values mean your biology looks older than your years.
The findings were clear: people whose MileAge delta showed older biological profiles faced higher risks of all-cause dementia, vascular dementia, earlier-onset dementia and unspecified dementia. The strongest link appeared for vascular dementia, suggesting blood chemistry tied to cardiovascular health matters a lot for brain outcomes. Nearly 4,000 of the study participants developed dementia during follow-up, giving the analysis some real-world weight.
Genetics amplified the signal. Participants who carried the APOE variant associated with Alzheimer’s disease and also had a higher MileAge delta experienced dramatically higher dementia risk. Study co-author Dr. Julian Mutz described that increased genetic risk as “striking.” The interaction looked multiplicative: genetic vulnerability plus older metabolic age created a much steeper climb in risk than either factor alone.
“The biological aging marker, MileAge, was especially predictive of vascular dementia, the second most common form of dementia,” he told Fox News Digital in an interview. That emphasis on vascular dementia fits with long-standing links between heart health and brain health, where high blood pressure, clogged arteries and obesity play clear roles. The metabolite signature may be capturing decades of cardiovascular strain that traditional risk checks miss.
Mutz stressed that MileAge isn’t set in stone. “While tenfold is a very large increase, it reflects the combination of a powerful genetic risk factor with an indicator of biological aging,” he said. “The important point is that these two sources of risk are complementary, and unlike genetic risk, metabolomic aging (biological aging measured through metabolites) is potentially modifiable through lifestyle or clinical intervention.” That sets up a hopeful angle: biology can change.
The team suggested common actions could make a difference—controlling blood pressure, staying active, watching weight and tending to mental health might slow metabolomic aging. Mutz added, “Dementia is not an inevitable consequence of aging.” Those are practical levers most people can use to tilt their metabolic profile toward younger signals and potentially lower dementia risk down the line.
Independent voices noted the study adds an important dimension to how we think about healthspan versus lifespan. Fox News senior medical analyst Dr. Marc Siegel pointed to the study’s message about prioritizing healthy years along with total years, noting the research highlights the APOE gene’s role. He said, “It emphasizes the role of the APOE gene in provoking dementia, especially Alzheimer’s,” and underlined how chronic illness raises dementia chances when that gene is present.
“There’s a 60% increased risk of vascular dementia when poor health is combined with this gene,” he said. “Vascular dementia correlates with heart disease, high blood pressure and obesity.” Those figures reinforce that metabolic and cardiovascular care aren’t just about heart attacks; they matter for cognitive survival as well. This research points clinicians and patients toward measurable blood markers that could someday guide prevention.
The authors acknowledged limits. Because the analysis is observational, it can’t prove cause and effect and relied on a single blood draw rather than tracking metabolomic age over time. The sample came mostly from people of European descent and participants tended to be healthier than the general public, so findings may not generalize to all groups. The researchers also noted MileAge needs further validation before it’s used in routine clinical practice.
Still, the study frames biological age as a potentially actionable metric, one that could sit alongside genetics and traditional risk factors when assessing dementia vulnerability. If follow-up work confirms the marker, clinicians might use metabolomic profiles to spot people who could benefit most from aggressive cardiovascular and lifestyle interventions. That’s a practical shift: from accepting dementia as an inevitable cost of getting older to treating aging biology itself as a modifiable risk.
