New study links antacids with increased risk of food allergy

ISLAMABAD: There may be a connection between taking a proton pump inhibitor or an H-2 receptor blocker and developing a food allergy, according to researchers in Austria.

"I think the implications are so important," said Dr. Erika Jensen-Jarolim, professor of medicine and immunology at the University of Vienna. "Our hypothesis appears to be right in that digestible proteins may act as food allergens when physiological digestion is hampered."

Dr. Jensen-Jarolim, who presented her study findings here at the World Allergy Congress on Wednesday, said individuals taking antacid medications, which affect acid secretion or neutralize the pH within the stomach, may be setting up a situation where harmless food proteins may turn into potential allergens. Gastric digestion depends on the presence of acid and pepsin, a protein-degrading enzyme activated at high acidic levels. However, elevation of pH levels hinders pepsin secretion, which hampers protein digestion.

The Austrian researchers conducted studies in which they fed mice hazelnut proteins and other typical food allergens. The mice did not develop a food allergy when given these proteins. However, they did develop food allergies in response to these proteins when they were given the proton pump inhibitor omeprazole, or the H-2 receptor blocker ranitidine.

Working with colleagues in Hungary, Dr. Jensen-Jarolim also found that this was the case when they conducted a similar study with 153 patients being treated with acid depression therapy. The data are very new and have not been published yet, Dr. Jensen-Jarolim told. "But it goes well with the animal data."

In the animal studies, the mice only developed allergic responses specifically directed at the novel protein, but not to components in their daily diet. Dr. Jensen-Jarolim explained that the body builds up a tolerance to foods normally consumed, and so it is only when an entirely new food source is introduced that a problem may occur. She said acid suppression may allow proteins to be introduced that produce an allergic reaction.

"This is the good news," said Dr. Jensen-Jarolim. "Stick to the diet you know and don't try exotic foods and don't make experiments." She said that an estimated 10% of the adult population is now being treated for dyspeptic disorders and many are taking over-the-counter medications. But she said for those individuals at high risk for food allergies, this may be a problem and they may want to discuss it with their physicians.

"H-2 receptor blockers are now on the store shelves and this may be creating allergy patients," Dr. Jensen-Jarolim said. "These medications are very important, but doctors may want to tell their patients that there may be this connection and patients shouldn't eat novel foods that they have never had before."