One of the first things people learn about me is that I have really horrific allergies. Because of this, I took it upon myself to learn about why I always sneeze. I’ve learned a lot over the years and, to get straight to the point it’s histamine I have to thank.
But before I get into the specifics, let’s talk about what causes your body to make histamine. Ragweed is the most common cause of allergy attacks in the fall. Ragweed is a plant you probably walk by every day and that’s where it gets you. More specifically, one of its billion pollen grains gets into your respiratory tract. Pollen is like plant sperm, a particle the plant sends out to fertilize another plant to make seeds. Pieces of the pollen grain bind to antibodies on immune cells in your airways. The immune cells release histamine and other factors that bind to different cells and result in (1) the expansion of the blood vessels, leading to the stuffiness and increased “leakiness” of your nose and eyes, and (2) the activation of neurons in the nose which signal to the brain that something bad is there, resulting in the sneeze.
Now back to histamine. Histamine is a tiny molecule that Benadryl targets. In fact, in the human body histamine has functions ranging from being a neurotransmitter in the brain to controlling the release of stomach acid to digest your food. Cool how a human body works, isn’t it?
Ironically, after suffering for years because of histamine, I’ve now chosen to earn my PhD by studying the mechanisms by which histamine fights inflammation and damage in the gut.