↑
Activity Levels
↓
Frailty Scores
↑
Movement Quality
What Is a Frailty Score?
Scientists measure aging in mice using a frailty index - a checklist of 31 age-related deficits including coat condition, hearing, mobility, grip strength, and body condition. Higher scores = more frail. The treated mice showed significantly improved frailty scores after gene therapy.
Observable Changes
The mice weren't just living longer in a cage. They were more active, moved around more, and showed behaviors typical of younger mice. This is the difference between adding years to life vs. adding life to years.
Why This Matters
Many life-extension treatments just delay death without improving quality of life. This study showed actual functional rejuvenation - the animals became biologically younger in how they moved and acted, not just in how long they survived.