Longevity02 sources

Transplanted hearts take on the biological age of their recipients

Diagram from the preprint showing a mouse with a graft heart attached to the neck vessels above its own native heart in the chest, the heterochronic heart-transplant model.

Poganik et al., bioRxiv preprint 2026 (CC BY 4.0)CC BY

A preprint posted to bioRxiv on 17 September 2026 reports that a transplanted heart takes on the biological age of the body it is placed in. The work, led by Jesse Poganik at Brigham and Women’s Hospital with Vadim Gladyshev and Steve Horvath among its authors, has not yet been peer reviewed.

In mice, the team grafted hearts into the neck, so each animal kept its own heart for comparison. Middle-aged hearts were placed in young adult mice and young hearts in middle-aged mice. Four to six months later, three molecular aging clocks, built on DNA methylation and gene expression, scored the grafts close to the age of their new host: old hearts read younger, young hearts read older.

Stored biopsies from heart-transplant recipients at Brigham and Women’s showed the same pattern. Recipients are typically about 20 years older than their donors, and the transplanted hearts’ biological age tracked the recipient’s age rather than the donor’s.

The effect ran in one direction only. A young heart did not rejuvenate the recipient’s blood or other organs. João Pedro de Magalhães of the University of Birmingham told MIT Technology Review that the recipient’s immune system may be shaping the aging markers measured in the graft.

Sources

  1. [1]Transplanted hearts assimilate the recipient's biological agebioRxiv··Preprint
  2. [2]Young organs may not be a fountain of youth for recipientsMIT Technology Review··Article