Are commercial biological age tests based on DNA methylation worth the money?

The tests measure something real, but which clock you use makes an enormous difference. That became clear in the CALERIE study: two years of eating 25% less slowed the rate of ageing in 220 adults, but only when measured with the DunedinPACE clock. The well-known clocks PhenoAge and GrimAge showed no significant change in that same study¹. Three clocks, three different answers to the same question. That is a fundamental problem when you buy a test to find out 'your biological age'.

The clocks are not worthless. In a study of 200 glaucoma patients, an accelerated epigenetic age was associated with faster deterioration of the visual field. Each additional year of acceleration gave a 15% higher chance of rapid glaucoma progression². But this is an association in a specific patient group, not evidence that the test works as a screening tool for ordinary people.

The more concrete clinical opportunities lie in early cancer detection. The THUNDER study validated a blood test that detects six types of cancer simultaneously. In an independent group of more than 1,000 people, the test achieved a specificity of ~99% (few false positives), but the sensitivity was ~69%. For early-stage cancer that dropped to ~60%³. One of the developers has commercial interests, which puts the results in a different light.

A cervical swab test for ovarian cancer also showed a signal: the probability of ovarian cancer was nearly three times higher with a positive result. But in the general population the chance that a positive test truly means ovarian cancer remains low, and the smarter combination strategy has so far only been modelled on paper⁴. Several authors here have commercial interests through Sola Diagnostics.

What practical use does it offer? DunedinPACE is most useful as a measuring stick in scientific research, not as a personal consumer measurement. The only proven way to influence that clock favourably was caloric restriction in a controlled study, with a small effect. A single standalone measurement provides no solid basis for lifestyle decisions. Cancer detection tests, moreover, have not yet been approved as standard screening.