By Dr. Paul Ehrlich
Our editor informs me that the old rumor about caffeine allergy is alive and well out in Twitterland. Let me say as plainly as I know how: a reaction to caffeine, no matter how real, cannot be an allergy. An allergy is an immune response to proteins or protein components in food, pollen, and other triggers. Caffeine is an alkaloid, and like other alkaloids such as morphine, cocaine, and nicotine, it is a drug, whose effects are as follows:
“In doses of 100-200 mg. caffeine can increase alertness, relieve drowsiness and improve thinking. At doses of 250-700 mg/day, caffeine can cause anxiety, insomnia, nervousness, hypertension, and insomnia. Caffeine is a diuretic and increases urination. It can curiously enough make it more difficult to lose weight because it stimulates insulin secretion, which reduces serum glucose, which increases hunger.
“Caffeine can help relieve some headaches, so a number of over-the-counter and prescription pain relievers include it as an ingredient, usually with aspirin or another analgesic.” (MedicineNet)
Those drug reactions are real enough, and account for many of the so-called “allergic reactions” that you can find when you put the words “caffeine allergy” into your browser. But calling them allergic reactions doesn’t make them so. One further test of the validity of caffeine allergy we’ll call the Google Test, or the Bing Test, or the Yahoo Test is this: when you put those words into a search engine, you don’t get a single entry from a medically reliable source. Put them into WebMD or the Mayo Clinic search engines and you get the medically polite equivalent of “huh?”
Normally this discussion rolls off my back. In our book we have a lengthy and lively section on the differences between food allergy and “pseudo food allergy.”
But it bears discussion this one (I hope) last time for this reason: It does a disservice to the individuals and families who are suffering from true food allergies, which are often life threatening. No one ever had anaphylaxis because the barista at Starbucks made a mistake. It doesn’t belong in the same discussion.
However, if you do suffer from the jitters—rhymes with Twitters—headaches, palpitations, insomnia, and so on, you can do the one thing that does work for real food allergies—lay off the stuff. Switch to decaf.