If you know anything about histamine (and you’re not a doctor or scientist who studies the stuff), it’s probably because of allergies. You need histamine for your immune response, but sometimes it gets carried away trying to battle things that aren’t actually threats. That’s an allergic reaction. A less talked-about aspect of histamine is how it reacts to your hormones.
Histamine actually used to be considered a hormone, but now it’s classified as a neurotransmitter. That means it sends signals between neurons and other cells to tell them what to do. It has roles to play in your immune response, your digestive health (releasing gastric acid), regulating sleep, and various other things.
When your immune system detects an outside invader, histamine is released to make the little blood vessels known as capillaries more permeable. This allows white blood cells to flow in and fight the threat, but it also causes other fluids to leak out. This is what leads to sneezing and runny noses in an allergic response.
So, what does this have to do with your hormones? Well, the mast cells that help produce histamine are stimulated by estrogen. Higher histamine then encourages the production of more estrogen, creating a vicious cycle where they both keep magnifying each other. As women tend to have more estrogen than men, this means they’re also more likely to have excess histamine levels.
In fact, histamine levels can vary widely throughout the month depending on where you are in your menstrual cycle. Times of major hormone shifts, like during puberty and menopause, can then cause even more dramatic changes in histamine that may result in new allergies that just didn’t exist at other points in your life.
Puberty means your estrogen levels are surging, while during menopause, progesterone levels can drop even quicker than estrogen. This is important because progesterone can inhibit histamine production by the mast cells. High histamine isn’t just about when your estrogen is high but when you don’t have enough progesterone to balance your estrogen. There’s some evidence your thyroid hormones may make a contribution as well.
Steps for regulating histamine may include changing your diet (some foods are higher in histamine than others) or various supplements. Trying to balance your hormones is trickier, but at least now you know they may be contributing to your symptoms.
