Blood Test Study of 80,000 UK Biobank Samples Could Reveal Earliest Signs of Dementia

A major new study will examine proteins in the blood of more than 80,000 UK Biobank volunteers in the hope of uncovering the earliest biological changes linked to dementia, Alzheimer’s Research UK has announced.

The charity is co-funding the project with the Michael J. Fox Foundation and LifeArc. It will be led by Alamar Biosciences and Nightingale Health, and is expected to finish by the end of 2027.

Researchers will analyse stored blood samples from UK Biobank, which has followed around 500,000 volunteers since 2006 and holds detailed information on their health, genetics and lifestyles. Using highly sensitive technology, the team will measure around 220 proteins linked to brain health, including some that have previously been difficult to study at this scale.

By matching the results with participants’ health records over time, the team hopes to identify changes in blood proteins associated with an increased risk of dementia. They will also explore why some people develop the condition while others do not, and examine the biological processes shared by Alzheimer’s and Parkinson’s disease.

The work will go beyond amyloid and tau, the two proteins that build up abnormally in the brain in Alzheimer’s disease and are already the focus of brain scans, spinal fluid tests and, increasingly, blood tests. Researchers are also interested in proteins linked to inflammation and nerve cell damage.

Once complete, the data will be shared with approved researchers worldwide.

Diagnosis currently relies on assessing a person’s symptoms, medical history, and memory and thinking abilities, with some patients also undergoing brain scans or lumbar punctures. Blood biomarkers could make the process more accurate and easier to carry out.

Alzheimer’s Research UK is already investigating the use of blood tests in NHS memory clinics through its Blood Biomarker Challenge, which focuses on people who already have symptoms. The new study will instead look at changes that may occur much earlier.

The charity stressed that the research has limits. Detecting signs of disease is not the same as knowing whether someone will develop dementia, as some people have Alzheimer’s-related changes in the brain for years without symptoms, and not everyone with these changes goes on to develop the condition.

Blood tests for Alzheimer’s are not yet widely available across the NHS, and the study will not produce a test that predicts who will develop dementia. Anyone concerned about changes to their memory or thinking should speak to their GP.

The charity said the findings could ultimately point to new ways of preventing disease, identifying people who might benefit from earlier treatment, and developing therapies that target the changes driving dementia.