We may age at different rates, but none of us escapes aging. A study in mice and human cells by Stanford Medicine researchers pins much of the blame on a particular type of immune cell’s increasing inability, with advancing age, to gobble up another immune cell type.

So-called tissue-resident macrophages appear to be central coordinators of age-related organ decline. Blocking a single receptor on these cells preserved the youthfulness of multiple organs in mice, including the brain, heart, skeletal and heart muscle, liver, spleen, bone marrow, kidney and colon. The receptor binds specifically to a hormone known to cause inflammation and pain in humans as well as mice.

In mice, selectively disabling this receptor exclusively on tissue-resident macrophages prevented chronic inflammation-driven disorders of aging, including frailty, excessive fat accumulation and heart trouble. It also substantially slowed cognitive decline, said Katrin Andreasson, MD, the Edward F. and Irene Thiel Pimley professor of neurology and neurological sciences.