It's not that it's going down, the article suggests that it slows.
If I lose 20 kilo's, my "biological age" might go down 2 years, but that doesn't mean it's "slowed"
If I lose 20 kilo's, my "biological age" might go down 2 years, but that doesn't mean it's "slowed"
Although one of the clocks they used, DunedinPACE, only looks at pace of ageing, so in that case you can only infer that it slowed (as you do not get an 'epigenetic age' figure from DunedinPACE).