The Aging Y: How Losing the Y Chromosome Could Impact Men’s Health

As men age, some cells can lose the Y chromosome, a change linked to higher risks of cancer, kidney and heart disease, Alzheimer's, and earlier death. Evidence from human studies and mouse models shows Y loss may impair immune function and cancer defense, and a sizable share of older men harbor Y-loss in tissues such as blood and tumors (e.g., bladder cancer). Ongoing debate asks how essential Y genes are and whether other chromosomes can compensate, though the chromosome has shrunk to roughly 3% of its ancestral genes and may not be doomed to vanish.