Scientists can now predict your Alzheimer's risk a decade before symptoms hit — and nobody in the press corps bothered to ask who else gets to see those results.
A blood test measuring a protein called p-tau217 can identify healthy older adults at high risk for cognitive decline within five to ten years, according to research published Wednesday in JAMA. People with very high levels of the biomarker faced a 38% risk of developing impairment over five years and a 78% risk over ten. The science is moving fast. The privacy framework isn't moving at all.
Three major outlets — CBS News, the New York Post, and AP News — covered the breakthrough. All three reported the same core findings from the Mass General Brigham team, which analyzed data from 2,684 older adults who were healthy when they enrolled in long-running Alzheimer's studies. About 478 developed cognitive impairment between 2004 and last year. All three noted that the test's immediate use is for clinical trials, not doctor's offices. None of the three addressed the obvious question: what happens when predictive medical data walks out of the lab and into the hands of insurers, employers, or government databases?
The study's senior author, Dr. Reisa Sperling of Mass General Brigham, stressed it's too soon for healthy people to seek out the test. "Wait and get tested when you can potentially do something about it," she said. "At this point it wouldn't change what I would tell someone to do. I'd still tell them to eat well, sleep well, exercise a lot and stay engaged."
That's sound medical advice. It's also a dodge. The technology to know your medical future is arriving whether there's a treatment or not. The Genetic Information Nondiscrimination Act of 2008 bars health insurers and employers from using genetic data to discriminate — but p-tau217 is a protein biomarker, not a gene test. GINA may not cover it. Long-term care insurers and life insurers aren't covered by GINA at all. The gaps are obvious. The law hasn't caught up.
Outside scientists flagged their own cautions. Drs. Suzanne Schindler of Washington University in St. Louis and David Wolk of the University of Pennsylvania noted in a JAMA commentary that only a small fraction of study participants were tracked for a full decade, making the 10-year risk estimate less reliable than the five-year figure. They also warned predictions could be clouded by other factors — older people may die from other causes, or develop vascular dementia from heart problems rather than Alzheimer's.
The research was presented at the Alzheimer's Association International Conference in London. Big pharma is already running large clinical trials on drugs that might prevent or delay the disease. If any succeed, doctors will need a way to identify who should take them — and that's where the blood test becomes a commercial product, not just a research tool.
The p-tau217 test works by measuring a form of tau protein that correlates with amyloid plaque buildup in the brain. Sperling described it as a window into a gradual process: "This is a gradual process where amyloid and tau build up in the brain and this blood-based biomarker is telling you how far you are in that process."
Right now, the test is used to help diagnose people already experiencing cognitive problems. The new study extends its predictive power to people who feel fine. That's the breakthrough — and that's the danger.
A tool that can forecast your mental decline a decade out is a weapon without guardrails. The researchers say wait. The law says nothing. The market won't wait.
