Aging clocks are research tools, not personal health guides. Peter Attia argues on The Drive that a single measurement from clocks like GrimAge can be thrown off by a recent heavy workout or a head cold, and lab-to-lab variation adds technical noise that masks real biological signals. The models compress complex systems into one number, losing the nuance needed for actionable health decisions.
The ultimate test for any mortality predictor is whether a company will bet billions of dollars on its accuracy. Life insurance companies are the world’s most precise actuaries, yet they haven't adopted epigenetic clocks.
Proven interventions show how little the clocks move. In the DO-HEALTH trial, which tested vitamin D, omega-3s, and exercise on 800 healthy adults over 70 for three years, results were inconsistent and underwhelming. Omega-3s showed a tiny improvement - roughly three months of "youth" gained over three years. Vitamin D and exercise had almost no measurable effect on the clocks, despite their well-documented benefits.
The insurance industry’s reluctance is the most telling signal. Insurers still rely on basic blood pressure, smoking status, and lipid panels, with payouts rarely deviating from their models by more than 1%. If aging clocks offered a superior edge in predicting death, the industry would have integrated them. For now, the field faces a divide between biomarker hype and proven clinical utility, with the old-fashioned markers remaining the gold standard for assessing real-world risk.
