Doctors advise against routine Alzheimer’s blood tests for asymptomatic individuals

The U.S. Food and Drug Administration has cleared four blood tests to help diagnose Alzheimer’s in patients who already show memory or cognitive problems, but specialists warn that these tests are not intended for people who feel well. "The worried well should not be getting those tests" outside of a research study, said testing expert Nicholas Ashton of Banner Health.

Researchers note that controlling common health issues such as high blood pressure, diabetes and smoking in middle age can delay the onset of dementia by up to 13 years, according to a large study led by Dr. Josef Coresh of NYU Langone Health. "Be aggressive," Coresh advised, emphasizing that early management of these risk factors yields a substantial benefit.

Although blood tests that measure the protein p-tau217 can indicate amyloid buildup in symptomatic individuals, a positive result only signals increased risk and does not guarantee disease development. A Mass General Brigham study found that older adults with very high p-tau217 levels faced a 38% chance of cognitive impairment within five years, but false-positive results remain possible.

One participant, 60-year-old Mark Yost of Phoenix, received an "intermediate" result in a Banner study and expressed disappointment over the uncertainty. He said he will continue brain-healthy practices such as regular exercise, a stimulating hobby and a balanced diet.

Clinical trials are ongoing to determine whether existing Alzheimer’s drugs can benefit people identified by these tests before symptoms appear, which could reshape future testing recommendations.