New Study Finds Link Between Acid-Blocking Drugs, Allergies

NEW YORK (CBSNewYork) -- There's a surprising connection between acid reflux and all sorts of allergies.

Acid-blocking drugs for reflux, known as PPIs and H2 blockers, are among the most commonly prescribed drugs in the country, CBS2's Dr. Max Gomez says.

The drugs are very good at stopping stomach acid -- the culprit in acid reflux, heartburn and GERD -- but when you fiddle with the body, you often get some unexpected side effects.

Ben Rosen has several health issues, but it was his acid reflux that really bothered him for years. That's why he's been on and off a variety of acid-blocking drugs.

Then, surprisingly, he developed a new problem.

"The doctor put me on one thing and another thing, and then I developed allergies," Rosen said.

It turns out it's not all the surprising.

A new study in the journal Nature Communications analyzed insurance data from than 8 million people in Austria and found a link in prescriptions.

"People that had or were on acid-blocking medications, such as proton pump exhibitors or what we call H2 blockers, had a sharp rise in the use of allergy medications," Dr. Purvi Parikh, with the Asthma and Allergy Network, said.

Given that these drugs are prescribed more than 100 million times a year, any possible link that suggests they may either cause or increase the risk for allergies is a cause for concern.

The puzzle is how these drugs might lead to allergies. There are some theories.

"Because the medicines are suppressing the acid in your stomach, it's not breaking certain foods down, and by not breaking those food proteins down, that gives you a risk of developing the allergy," Parikh said. "Because then the immune system might recognize it as something that is foreign or bad."

Another theory is that the drugs might unsettle the normal bacterial microbiome in the gut, which could also disrupt the immune system.

Cutting down on the acid blockers has helped Rosen's allergies.

"Other than some ragweed in the air, I'm feeling pretty good," he said.

The study does not prove cause and effect, however. It's only a statistical link.

The problem for many people is that they may need acid-blocking drugs for their reflux, even if they have allergies, and acid reflux can also aggravate allergic conditions like asthma or sinus problems.