Gerontologist Nir Barzilai warns looks mislead on health

Nir Barzilai, director of the Institute for Aging Research at Albert Einstein College of Medicine, told El País in Madrid that “just because you look young doesn’t mean you’re healthy,” arguing that longevity has a large “biological lottery” component even among people who reach 100. In the same interview, he put the statistical ceiling of human lifespan at about 115 years and said the practical question is whether medicine can turn today’s average death at roughly 80 into “35 healthy years” rather than a longer period of frailty.

The remark lands in a market that increasingly sells “biological age” as a number you can buy, lower, and re-test. The problem is that biology offers many numbers, and the industry is free to pick the ones that move fastest. Epigenetic clocks based on DNA methylation can correlate with mortality risk in large datasets, but different clocks can disagree on the same person, and short-term changes after diet, exercise, illness, or medication can look like “reversal” without proving that long-run risk has changed. Inflammation panels (CRP and related markers) can reflect genuine risk in populations, but also transient infections, sleep loss, or training load; a low reading is not a certificate of slow aging. Glycan-based measures, VO2 max, and grip strength are closer to functional capacity than to cellular aging, yet they too are sensitive to training, injury, and measurement protocol.

Barzilai’s own work, as described by El País, points in an opposite direction: rather than treating aging as a dashboard of tweakable biomarkers, he sequences centenarians’ genomes to find variants that appear to protect against disease. He highlights CETP and APOC3 variants found in some centenarians, linked in the interview to higher “good” cholesterol, lower triglycerides, and reduced inflammation—traits that drug developers have tried to mimic. That approach still faces the usual hurdles: a genetic association is not a therapy, and a therapy that shifts a lab value does not automatically deliver fewer heart attacks, less dementia, or longer healthspan.

The business model in longevity testing does not wait for that kind of proof. Frequent retesting creates recurring revenue; adding more markers creates a sense of comprehensiveness; and “personalized” reports can be generated even when clinical decision thresholds are unclear. The consumer receives a number; the provider receives a customer who now has a baseline and a reason to come back.

Barzilai’s caution is not a regulatory proposal or a product launch. It is a reminder that the easiest thing to measure is not always the thing that matters, and that the most marketable claim is often the one least constrained by outcomes.

Helen Reichert, the centenarian Barzilai described, credited hamburgers, beer, cigarettes, and nightlife for her longevity and died at 109. Her story is memorable partly because it does not fit on a lab report.