Crispy, it's all explained in the post above, this one:
https://www.larabriden.com/the-curious-link-between-estrogen-and-histamine-intolerance/ Quote:
The connection between mast cells, histamine, and hormones is that:
* Estrogen stimulates mast cells to release histamine and down-regulates the DAO enzyme that clears histamine.
* At the same time, histamine stimulates the ovaries to make more estrogen.
* The net result can be a vicious cycle of estrogen → histamine → estrogen → histamine.
Progesterone stabilises mast cells, up-regulates DAO, and can therefore reduce histamine.
It's about reducing the histamine overall as much as you can. Many foods are extremely high in histamine which we regularly eat. If you almost eliminated the histamine you were eating, it would very likely be sufficient - after all, our bodies are supposed to cope with some amount of estrogen and the amount in HRT is not that high. A state of zero estrogen (as we all know!) is extremely bad for your health so that's definitely not what the goal is. It's when we massively increase histamine through what we ingest that things get a bit crazy.