How the LA Times Got it Backwards

By Dale Bredesen, M.D., Chief Science Officer for Apollo Health

An op-ed in the LA Times by Dr. Keith Vossel on November 10 suggested that “too many people are getting tested for Alzheimer’s.” With all due respect to my neurological colleague, Dr. Vossel, I disagree wholeheartedly. He suggests that “the biomarker test should only be taken if you are truly showing signs of Alzheimer’s disease,” which is like saying that you should only have a mammogram if you notice a lump in your breast, avoid a chest X-ray until you cough up blood, and not bother to check your hemoglobin A1c for diabetes until you start to lose your vision. Sticking our heads in the sand and awaiting symptoms is an antiquated approach to health care.    

Early screening for complex chronic diseases such as cancer, diabetes, and cardiovascular disease has been the most potent weapon against these agonizing diseases that limit our lifespans and healthspans. Cervical cancer deaths have been reduced by more than 50% thanks to the Pap smear; mammography prevents 12,000 deaths each year (and high-sensitivity ultrasound is even more sensitive); and colonoscopy reduces colorectal cancer death risk by 80%.

Alzheimer’s disease has been, until now, an intractable problem, and without effective prevention and treatment, about 45 million of the currently living Americans will die of Alzheimer’s, dwarfing the mortality of the COVID-19 pandemic. Now, for the first time, we have simple blood tests that can reveal the earliest processes of Alzheimer’s disease, prior to any symptoms, allowing dementia to be avoided in the vast majority of people. That is a major advance, a paradigm shift that will ultimately render Alzheimer’s-related dementia a rare condition. 

Dr. Vossel goes on to state, “My stance on widespread testing will be different when doctors have more tools available to predict and treat Alzheimer’s and can offer constructive advice after a blood test comes back positive.” This stance completely ignores the new field of precision medicine, and the remarkable results achieved in patients with Alzheimer’s using a precision medicine approach. Precision medicine, which has been very successful in cancer treatment, targets the underlying drivers of the condition with a personalized approach, rather than a one-size-fits-all treatment that ignores the cause and contributors. This method has now been applied successfully to Alzheimer’s disease, with the best results coming when treatment is started early—exactly what the new blood tests now allow. One of the patients who has shown dramatic and sustained improvement with this new approach criticized doctors who offer “false hopelessness” in a new era in which repeated successes along with early detection offer hope for all.  

I  do agree with Dr. Vossel on one point: hearing that you “have Alzheimer’s” can be frightening and depressing, no matter whether you have symptoms or not. For this reason, it would make sense to follow the precedent of the diabetologists, who diagnose pre-diabetes in those whose blood tests show they are on the path to diabetes if they do not undertake the appropriate treatment. This has helped many to avoid the blindness, kidney failure, vascular disease, and other effects of diabetes. Similarly, using the term “pre-Alzheimer’s” for those with positive biomarkers but without symptoms, or with minimal symptoms, and explaining that much can now be done to avoid the dementia associated with late-stage Alzheimer’s would provide a win-win: patients would be encouraged to come in early, when prevention and treatment are most effective, and the shock of being told one has Alzheimer’s disease would be mitigated—and, over the long run, replaced by well-founded hope.

Dr. Vossel also states that reaching the conclusion that someone has Alzheimer’s based on biomarkers “is like diagnosing cancer without doing a biopsy.” On the contrary, multiple studies have shown what the biomarkers detect, and just as a biopsy samples a tumor, the blood-based biomarkers reveal ongoing Alzheimer’s biochemistry within the brain—literally a liquid biopsy, since the brain is in constant contact with the blood. 

The op-ed recommends that biomarker testing should not occur until significant symptoms are present, such as losing track of time and place, struggling to find words, and personality changes, but these are late-stage symptoms. The development of Alzheimer’s disease is a process that occurs over approximately twenty years, in four phases: (1) an asymptomatic phase; (2) SCI, or subjective cognitive impairment, which is often mistaken for “normal aging”; (3) MCI, or mild cognitive impairment; and (4) dementia. The symptoms listed by Dr. Vossel would not allow biomarker testing until the MCI phase, i.e., the third of four phases, and thus lose precious years and compromise outcomes, leading to dementia needlessly in millions of patients.

On January 4, 2011, President Barack Obama signed into law the National Alzheimer’s Project Act (NAPA), and one of the stated goals of NAPA is to develop an effective treatment for Alzheimer’s disease by 2025. I was present at the first NIH meeting to respond to this Act, in which HHS Secretary Kathleen Sebelius impressed upon us the dire need for new, innovative approaches to reduce the burden of Alzheimer’s disease on families throughout the world. Sensitive blood biomarker tests, coupled with precision medicine, are the two advances that will allow us all to realize Pres. Obama’s directive in signing NAPA into law.

Therefore, I strongly recommend that we all check our blood pressure, get our chest X-rays, our colonoscopies (or colonoscopy alternative), our Pap smears, our hemoglobin A1c (or, for earlier detection, fasting insulin), our ApoB (as a predictor of vascular disease), our calcium score (for coronary artery compromise), and other lifesaving, disease-predictive tests; and, for anyone who is over 35 (yes, there has been a striking rise in Alzheimer’s diagnosed in the 40s and 50s), please consider Alzheimer’s blood tests such as p-tau 217 every five years or so, so that you can avoid the dementia phase of Alzheimer’s disease and stay sharp for years to come. For those interested in reading further, click here.