There’s like. a speck, a teeny tiny sliver of truth in the claim that we menstruate more now than we used to. It is NOT because of toxins.
It’s is because:
We do not experience famine as often as we used to. Famine = lack of energy & low body fat = energy preservation by stopping menstruation, And preventing pregnancy on a woman’s already depleted body.
We are pregnant less often, and breast feed for shorter durations. Both is which stop menstruation (breast feeding only for a period of time, it usually starts again while still feeding depending on the mothers own energy / nutrition)
Menarche occurs younger, girls are going through puberty younger possibly due to better nutrition in childhood.