An international team of researchers has identified a blood protein that can signal dementia risk decades before symptoms appear. The protein, called GDF15, was measured in middle-aged individuals from large cohort studies in the US, UK, Iceland, and Japan.
Data from tens of thousands of people, followed for up to 25 years, showed that higher levels of GDF15 at age 55 or younger correlated with a significantly increased likelihood of developing dementia later in life. The association was particularly strong for vascular dementia.
The researchers used genetic analysis to show the relationship is likely causal, not merely correlational. Variants linked to higher GDF15 levels were also linked to higher dementia risk, independent of lifestyle factors. Further analysis of brain scans and cerebrospinal fluid confirmed the link, showing elevated GDF15 in the blood was associated with brain shrinkage.
Lab tests on immune cells revealed GDF15 may interfere with immune response and energy pathways. While the protein normally helps regulate the immune system, researchers theorize that in the context of dementia, it may over-suppress immunity, leaving the brain vulnerable.
These findings position GDF15 as both a potential early warning biomarker and a possible driver of dementia pathology, particularly for vascular and neuroinflammation-related forms.