Even though the reproductive age for humans is around 15 — 45 years old, the
precursor cells that
go on to produce human eggs or sperm are formed much earlier, when the fertilized egg grows into a tiny ball of
cells in the mother's womb.
Instead, they stay elevated,
going beyond what the
cells can handle, and eventually this triggers a chain of effects that lead to insulin resistance, the
precursor to high blood pressure, heart disease, diabetes, obesity, possibly Alzheimer's disease, and even some cancers.