Studies using both knockout mouse models as well as pharmacological studies have revealed that histamine acts as an anorexigenic agent via stimulation of histamine H(1) receptors. One effect of histamine in the regulation of appetite is to act as a mediator of the inhibitory effect of leptin on appetite. It seems that histamine may attenuate and delay the development of leptin resistance in high-fat-diet-induced obesity. Furthermore, histamine may also act to accelerate lipolysis. Based on the current evidence of the involvement of histamine in the regulation of body weight, the histaminergic system is an obvious target for the development of pharmacological agents to control obesity. At present, H(3) receptor antagonists that stimulate the histaminergic system may be the most promising histaminergic drugs for antiobesity therapy.
I also found this study about histamine intolerance mimicking anorexia nervosa.
Histamine intolerance is a clinically heterogeneous disease. We present a woman who suffered from weight loss, diarrhea, abdominal pain, headache, flushing and bronchial asthma for several years. When placed on a histamine-poor diet, she experienced weight gain and improvement of other all signs and symptoms, supporting the diagnosis of histamine intolerance. Therefore, this disease should be included in the differential diagnosis of anorexia nervosa.
What I’m not (yet) entirely clear on, is why, though high histamine may lead to lower/normalising the appetite (or in extreme cases anorexia), did I suddenly lose so much weight on a low histamine diet? Granted, I cut a lot of crap out of my life, but I was always a really healthy eater. My friends frequently commented on my “weirdo” metabolism because I never really ate much and I exercised loads and yet I just couldn’t shift the sudden gain.
My research tells me that it’s because more than one histamine receptor is involved in the regulation and rate of fat burning. So while I have reduced my overall level, I may have helped my histamine system function more normally – the idea being that the histamine receptors should be firing at certain levels rather than being out of whack as they were (thanks to my antihistamine use). Maybe my body was always meant to be skinny, so fixing my diet helped my body regain it’s natural state? My weight, which used to fluctuate by up to 10 kilos (22lbs) every few months, has now held steady at 58-60kg (125-130lbs) for the last two years without any effort whatsoever on my part. I do exercise, but raise my caloric intake accordingly (i.e. taste test new dessert recipes) when I do.
I’m now one of those chicks I used to love to hate: I eat when I want, what I want, and I don’t gain weight. And I do love my desserts…
There’s always an upside – you just need to look hard enough for it!