13/03/2026
A blood test can predict the risk of dementia in women up to 25 years before symptoms appear, according to new research.
Researchers from the University of California San Diego examined data for 2,766 women in the Women’s Health Initiative Memory Study, a large US study that enrolled women aged 65 to 79 in the late 1990s and followed them for up to 25 years.
Blood samples collected at the start were analysed, and again years later to measure p-tau217 - a protein linked to the brain changes seen in Alzheimer’s disease.
During the 25 years of follow-up, researchers noted the women who developed memory or thinking problems, including dementia.
This study suggests that there may be a correlation for women between having a higher level of the p-tau127 biomarker earlier in life with an increased risk of developing dementia 25 years later.
These findings are promising, but of course more research is needed to understand whether early identification of biomarkers can affect whether people will go on to develop dementia later on.
Blood tests could transform how dementia is diagnosed.
Research we're funding aims to make a blood test routinely available on the NHS for symptomatic Alzheimer’s disease within the next few years, so everyone who needs a diagnosis can get one quickly and accurately.
Dementia research is making huge progress and bringing great hope, and we’ll continue to invest in pioneering research to ensure people get the diagnosis, treatment and support they deserve.