Blood Test May Predict Dementia Risk Before Symptoms Appear

More than 6 million Americans have dementia, a progressive brain disorder that affects memory, language, problem solving and judgment. Symptoms include forgetting names or recent events, expressing confusion about time and place, and struggling with daily routines.

A study published Wednesday examined data from over 220,000 UK residents, including nutrients and hormones in their blood known as metabolites, incidence of dementia, and age of symptom onset.

Nearly 4,000 participants developed dementia during the study period. Biological age can increase faster than chronological age because of cellular damage from stress, poor habits, and environmental factors such as pollution and extreme heat.

The age difference link was more pronounced for vascular dementia, which affects thinking skills and is the second most common form of dementia after Alzheimer’s disease. About 16 percent of participants had a 20 percent greater risk of dementia because they had an age gap greater than one standard deviation from the mean. The risk was 60 percent greater for vascular dementia.

Those with older biological ages and two copies of APOE4, the strongest genetic risk factor for late-onset Alzheimer’s, were 10 times more likely to develop dementia. A spokesperson said the findings suggest that biological aging data can help identify individuals at risk of dementia before clinical symptoms emerge.

The spokesperson added that combining genetic factors with potentially modifiable factors captured in biological aging may allow development of preventative strategies, potentially based on a simple blood test.

Without major intervention to curb unhealthy lifestyle choices, U.S. dementia cases are expected to double by 2060 to nearly 1 million new cases annually. Known risk factors include chronological age over 60, high blood pressure, diabetes, tobacco use, sedentary lifestyle, brain injury and family history of the disease.

Biological aging clocks based on metabolites have existed for at least a decade and continue to be refined. The spokesperson said blood plasma-based clocks are scalable and minimally invasive. They could potentially be part of mid-life screening or used to help refine the selection of individuals for research into prevention or disease-modifying trials for dementia.