For more than a decade, the "dad bod" has been celebrated, mocked and memed as the inevitable physique of married men with kids. But the term is more than a cultural phenomenon.
Why it matters: There's growing scientific research that fatherhood changes men's bodies and brains — even though these changes are rarely discussed.
The world's first human trial of whether a drug can essentially make a person's cells younger sets up a reality check for one of the longevity field's most promising theories.
Why it matters: The early-stage clinical trial will signal whether "cellular reprogramming" can be performed safely in humans, a prerequisite for any future claim that a treatment can slow or even reverse biological aging.
