Researchers at Bar-Ilan University in Israel have demonstrated that aspects of cellular aging can be reversed, not just delayed. In a study published in Nature Communications, the team showed that increasing activity of the Sirt6 protein in 24-month-old mice—equivalent to humans in their 70s and 80s—restored the chromatin structure in liver cells to a youthful state within about a month. Chromatin organization affects how DNA is read and repaired, and its deterioration is a hallmark of aging.

Beyond molecular changes, the treated mice showed reduced inflammation, improved metabolism, and activity levels resembling younger animals. No harmful side effects were observed, and the rejuvenated state persisted for at least three months post-treatment—suggesting long-lasting effects. This marks the first evidence that Sirt6 can reverse, rather than merely slow, age-related decline when activated late in life.

The findings open the door to therapies targeting aging itself, rather than individual age-related diseases. One potential application is improving recovery in elderly patients after surgery or illness. The Israeli biotech company SirTLab is already developing Sirt6-activating treatments and seeking funding for clinical trials, though human applications remain years away.