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It’s a question worth billions of dollars. Companies want to sell you tests that reveal your “biological age.” Genetic tests promise to predict your dementia risk decades in advance. Your doctor calculates your 10-year probability of a heart attack. A recent Wall Street Journal article explored longevity calculators simply to figure out how much money to save for retirement — with estimates ranging from age 86 to 102, hardly a useful planning tool.
But here’s the question almost nobody is asking: even if these predictions are accurate, can you actually do anything about them?
Take the poll below and let everyone know what you think.
In my latest podcast episode of Live Long and Well With Dr. Bobby, I explore this topic with Dr. Anthony Pearson, a preventive cardiologist and author of the widely-read Skeptical Cardiologist Substack. Together we examine three categories of health prediction tools — cardiac risk equations, genetic dementia testing, and biological age clocks — and ask the same hard question about each one: does knowing this actually help you live longer?
How Risk Prediction Tools Are Built
Before evaluating any prediction tool, it helps to understand how they’re made. Researchers start with a large database that tracks both outcomes (heart attacks, dementia, death) and clinical factors (blood pressure, cholesterol, smoking, age). They look for correlations, build a statistical equation, and — ideally — test whether improving those risk factors actually reduces bad outcomes.
That last step is critical, and it’s almost never done.
The gold standard here is the Framingham Heart Study, launched in 1945 after Franklin Roosevelt’s death from a stroke prompted Congress to fund a major investigation into cardiovascular disease. At the time, heart attacks were considered essentially inevitable — doctors didn’t even know that high blood pressure was a cause. Framingham changed everything. By tracking thousands of residents in Framingham, Massachusetts over decades, researchers identified the now-familiar culprits: hypertension, high LDL cholesterol, smoking, diabetes, and elevated blood sugar.
Crucially, cardiac medicine went further. Clinical trials demonstrated that lowering those risk factors — with medication, lifestyle change, or both — actually reduced heart attacks and deaths. The prediction tool connected to a real intervention. That’s the standard every other prediction tool should be held to.
The Best Tools Still Miss Half the People
Even cardiac risk prediction, the most rigorous in medicine, has sobering limitations. In a study published in JACC Advances, researchers looked at 465 people under age 65 who had suffered a heart attack and asked whether the standard risk calculator would have flagged them in advance. The answer: half of them had been classified as low risk.
This is worth sitting with. Our best, most validated, most evidence-backed prediction tool still misses one in two younger heart attack patients. Keep that benchmark in mind as we look at less-developed tools.
Genetic Testing for Dementia: Useful, but Incomplete
The APOE gene comes in three variants — E2, E3, and E4 — and you carry two copies. The most common combination, E3/E3, is found in about 60% of Americans and carries a 10-15% lifetime dementia risk by age 85. The protective E2 variant roughly halves that risk. But the E4 variant is where things get serious.
One copy of E4 doubles or triples your dementia risk. Two copies — present in about 2% of the population — raises your risk to somewhere between 50 and 65% by age 85.
This is genuinely useful information — but with an important caveat. The APOE gene is not determinative. Many E4 carriers never develop dementia, and plenty of people without the gene do. And there is currently no medication or targeted therapy that changes the outcome for E4 carriers. What we do have is evidence that lifestyle factors — consistent exercise, quality sleep, blood pressure control, limiting alcohol — reduce dementia risk across the board. If knowing your APOE status motivates you to double down on those habits, the test is worth doing. If it would simply paralyze you with fear, skip it.
Biological Age Clocks: Fascinating Science, Premature Product
This is where the hype dramatically outpaces the evidence.
Biological age tests — measuring DNA methylation, telomere length, proteomic markers, or other indicators of cellular aging — are being marketed directly to consumers at prices ranging from a few hundred to nearly two thousand dollars (for a series of 4 during the year). The pitch is intuitive: your body may be aging faster or slower than the calendar suggests, and if we can measure that, we can fix it.
The problem is that the science doesn’t yet support these biologic clocks for routine/non-research use.
Three fundamental issues undermine today’s biological age tests. First, there is no consensus on what to measure. Different tests look at different biological processes and frequently disagree — a peer-reviewed reliability study found results varying by as much as nine years across six different tests run on the same individuals. Your liver might appear “old,” your heart “young,” and your lungs average. What are you supposed to do with that?
Second, the tests lack reproducibility. Sending the same biological sample to the same company twice could yield results five to ten years apart. A measurement that varies that widely is not a measurement — it’s noise.
Third, and most importantly, no biological age test has ever been validated against actual health outcomes. For cardiac risk factors, we know the chain of evidence: high LDL predicts heart attacks, and lowering LDL reduces them. For biological age clocks, that chain is broken. Even if a test accurately measured your cellular age — which hasn’t been established — there is no study demonstrating that improving your score leads to longer life or better health.
No consumer-facing biological age test has been approved or validated by any regulatory body. There is no industry oversight or quality control transparency. These are, for now, research tools being sold as consumer health products.
A Word on Where Health Information Comes From
Before accepting any health claim at face value, it’s worth knowing this: a study published in JAMA Network Open examined 309 health-related YouTube videos produced by doctors and found that 62% of the claims made had little or no supporting evidence. Only 20% of videos were grounded in high-quality evidence. Most striking of all — the videos with the lowest evidence scores had 35% more views. Confidence, it turns out, is more compelling than accuracy.
This is exactly why I founded Live Long and Well on a commitment to reference-backed analysis. When I hear a claim, I want you to be able to check the source yourself.
The Bottom Line
Prediction tools are only as valuable as what you can do with the predictions. Cardiac risk equations, for all their imperfections, connect to proven interventions. Genetic dementia testing can inform lifestyle prioritization, even without a pharmaceutical fix. Biological age clocks, despite the compelling marketing, remain scientifically premature.
My recommendation: pay attention to the risk factors that have decades of evidence behind them — blood pressure, cholesterol, blood sugar, smoking, sleep, exercise. Be skeptical of any test that costs hundreds of dollars, claims to reveal something transformative, and is sold by someone who also happens to be selling the solution.
Be an open-minded skeptic. Ask what the evidence is, not just how confident the person sounds. The two are very different things.
Listen to Episode 63 of Live Long and Well wherever you get your podcasts.
