Antihistamines and Weight Gain
A recent study published in the journal Obesity shows a link between H1 type antihistamines and weight gain. The study found increases in weight, waist size, and insulin levels compared to control groups.
This is an obvious concern, because antihistamines are such a commonly prescribed and used class of medications. However, like so many other medications, antihistamines have side effects, and weight gain appears to be among them.
What’s an H1 antihistamine?
H1 antihistamines are medications that block the histamine receptors to reduce the inflammatory process. Histamine is a chemical released by the body to signal the start of inflammation, and like most chemicals that act on the body, certain parts of the cell have receptors that recognize that histamine is around. Once the receptor comes into contact with histamine, bingo… inflammation starts.
Rather than prevent the release of histamine, H1 antihistamines block the receptor, so histamine is still floating around, your body just can’t see it. They also tend to make you drowsy as a side effect, which may account for part of the weight gain effect.
Common H1 antihistamines are Allegra, Clarinex, and Zyrtec.
Antihistamines and Weight Gain
This study took the results of data from a big survey done back around 2005 and compared antihistamine takers to non antihistamine takers. After controlling for factors such as age and gender, the researchers found a correlation between taking prescription antihistamines and the weight gain factors mentioned earlier; weight, waist size, and insulin levels.
How much weight? Women taking these drugs were about ten pounds heavier on average.
As always, it’s important to note that correlation is not causation; just because we see two things occuring at the same time doesn’t mean one causes the other. It could be that people with bad allergies just don’t exercise as much as people without allergies.
However, it is especially concerning to me that there was an effect on insulin levels as well as weight gain, considering the serious out-of-control issue this country has with the incidence of diabetes. People who are currently having problems with insulin resistance or diabetes should definitely bring this study to the attention of their physician if they are considering taking antihistamine medication.
Other, non-medication options for reducting inflammation include taking heavy-duty OPC type antioxidants like pycnogenol and resveratrol. I cover more on this topic in this article on antioxidants and inflammation.
Stay healthy!