Another theory suggested in the Yale study was that histamine, which is the neurotransmitter that overreacts when you come into contact with an allergen, has a secondary role in regulating your appetite.Animal studies have shown that dosing mice with histamine reduces their food intake, while dosing them with antihistamines increases their appetites.Therefore, it stands to reason, the authors noted, that if you take a lot of antihistamines, that might cause you to eat more.
The researchers warned that this was an observational study, and couldn't demonstrate whether antihistamines actually caused the weight gain or if obesity predisposes people to allergies. Using data from the same CDC survey, researchers found that obese children were more likely to suffer from allergies, specifically food allergies, than normal-weight children."It wasn't clear to us if that really meant that the obesity was the cause of that allergic propensity or not," says Cynthia Visness, Ph D, the study's lead author and a research scientist at Rho Inc., the research firm that conducted the study.Researchers have suggested that allergies and weight gain go hand in hand, and that could have to do with the drugs you take or more subtle underlying problems.In August 2010, researchers from Yale University published a study in the journal finding that people who took antihistamines regularly were heavier than people who didn't take them at all.So if you want a medication that won't make you prone to skipping workouts, choose one of the non-sedating medications.
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However, Zyrtec may make you more tired than the others.
It's considered a minimally sedating antihistamine, unlike Allegra and Claritin, which are non-sedating.
The study's authors used data from the Centers for Disease Control and Prevention's (CDC's) National Health and Nutrition Examination Survey 2005–2006 to compare the body weight of 867 adults and their prescription antihistamine use.
The two drugs most common in the study were cetirizine, now sold over-the-counter as Zyrtec, and fexofenadine, also now sold over-the-counter as Allegra, and the effect was more pronounced in men.
So I wanted to see if anybody else suffers from the similar issues.