Does it seem as if everyone you know (including, perhaps, you) has recently come down with a food allergy?
No surprise. According to Food Allergy Research and Education, 15 million Americans are allergic to a menu’s worth of everyday foods, such as milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish. Food allergies among children rose about 50 percent between 1997 and 2011, according to the Centers for Disease Control and Prevention.
No one knows the reason for this alarming increase, but what if these “allergies” aren’t caused by the body’s mistaken response to otherwise harmless foods? What if 70 years of exposure to powerful yet untested-for-safety chemicals are somehow knocking our bodies’ delicate balance out of whack – and causing allergylike symptoms that aren’t, in fact, allergies?
That’s the hypothesis behind toxicant-induced loss of tolerance, or TILT, an as-yet-unproven disease mechanism first proposed in 1996 by Dr. Claudia Miller of the University of Texas Health Science Center and her colleague Nicholas Ashford from Massachusetts Institute of Technology.
In addition to the unexplained increase in food allergies, Miller believes TILT may be the culprit behind such baffling illnesses as chronic fatigue, Gulf War syndrome and fibromyalgia, and recent spikes in childhood autism and attention deficit disorder.
Not everyone agrees with her hypothesis, however.
“There’s no mechanism to explain how exposure to a chemical makes you more sensitive to this or other chemicals, or how it causes this vast array of diseases,” said Dr. Karin Pacheco from the National Jewish Health Medical Center in Denver and a member of the environmental and occupational respiratory disease interest section of the American Academy of Allergy, Asthma & Immunology. “It’s a very vague theory.”
We know how diseases such as colds and flu are caused by bacteria, viruses and other microorganisms. And how allergies are caused when the body’s immune system misidentifies and attacks otherwise harmless substances, such as the gluten protein in wheat, triggering an allergic reaction.
TILT is more complex.
It starts with exposure to a broad range of synthetic organic chemicals, such as pesticides or the highly volatile compounds used in adhesives, paints and other construction materials. Most of these chemicals have been developed only since the end of World War II, so our bodies aren’t adapted to them. They don’t affect everyone the same way, but those who are more susceptible – for some unknown reason – can become intolerant of other everyday substances that never bothered them before, including foods.
“Foods are the key,” said Miller. She points to studies done in multiple countries in which people exposed to these chemicals later report new food intolerances.
“Why would people who don’t know each other, who don’t speak the same language and who happen to have had what we call an identifiable exposure event report developing food intolerances?” she said.
Miller concedes that there’s no proven link between these exposure events and the symptoms, and that there’s no biological marker to test for TILT.
“It’s not like with allergies, where you can do a skin or blood test and say, ‘Yes, you’re allergic to peanuts,’ ” she said. “Of course, there was a time when we didn’t have those tests, either. We have to put things in historical perspective.”
The lack of diagnostic tests and proven treatment can put patients at risk. Pacheco, from the American Academy of Allergy, Asthma & Immunology, warns against medical quacks who treat chemical exposure with unproven (and expensive) vitamin and dietary supplements.
“I’ve had patients (who) spent thousand of dollars on these supplements, which aren’t covered by insurance,” Pacheco said. (It must be noted that Miller is a researcher and does not treat patients.)
To help identify those with TILT, Miller and Ashford have developed the Quick Environmental Exposure and Sensitivity Inventory, a do-it-yourself screening tool for chemical intolerance. Find it at www.qeesi.org.
Because we still don’t know the mechanism behind TILT, there’s no active treatment to prevent or cure it. The best Miller can come up with is to avoid exposure to these chemicals, especially by those most at risk, including children, pregnant women and anyone with a history of chemical intolerance.
If you are exposed, eliminate or reduce any future exposure.
“There are some people who figure out the chemical causing the problem and, by avoiding it, they report their intolerance to food resolves over time,” Miller said.