Harvard: Transplanted Organs Adopt the Recipient's Biological Age

Researchers at Harvard Medical School grafted extra hearts onto young, middle-aged and old mice and measured DNA methylation after six months. Young hearts in old bodies aged faster, while old hearts in young bodies grew biologically younger; the same effect appeared in 11 human heart transplant cases.

• Young hearts in old mice aged faster; old hearts in young mice grew younger
• Effect confirmed in 11 human donor-recipient pairs with 8–50 year gaps
• Likely cause is exchange of accumulated damage between body and graft
• Finding could expand the donor pool to include older organs