Are You Allergic to Red Meat?
By DR. MALCOLM THALER
Red meat has its problems: The more you eat, the greater your risk of heart disease and -- especially in the case of processed meats like bologna and hot dogs -- the greater the risk of mortality from both cardiovascular disease and cancer. In addition, the amount of energy and food required to raise a healthy animal is an ecological nightmare.
Fortunately, one of the major problems associated with eating red meat -- the vast amounts of antibiotics poured into animal feed that leads to the emergence of bacteria resistant to multiple antibiotics -- is finally being addressed. But now a new problem has emerged: Some people are experiencing severe allergic reactions when they eat red meat.
What are the symptoms?
Thousands of people in the U.S., extending from Texas up to the Northeast, are experiencing allergic reactions several hours after they eat red meat. The reactions can range from itching and hives to more severe symptoms like vomiting, diarrhea, shortness of breath and a sudden drop in blood pressure that can cause fainting. These symptoms can be so severe that they require emergency care.
What's causing these reactions?
Interestingly, a tick bite -- in particular, the bite of the lone star tick. We all know about other tick-borne illnesses, such as Lyme disease and Rocky Mountain spotted fever, but this is something new, only first described a few years ago.
Epidemiologic studies suggest that the populations of lone star ticks have been spreading out of the southeastern U.S. as far north as Canada, and this likely accounts for the increasing incidence of these reactions. The reason for the spread is not clear.
The cause appears to be a sugar (galactose-alpha-1, 3-galactose -- aka alpha-gal) that the lone star tick harbors in its gut and expels when it bites someone. Humans don't carry this sugar, but animals do. If a lone star tick bite sensitizes you to the sugar, then you may experience a potent immune reaction when you eat beef, pork, lamb and even dairy products from these animals.
[Read More: The Problem With Cage-Free Eggs]
The reaction is usually delayed about two to eight hours after eating. The first sign is typically itching or a burning in the throat, but the reaction can then progress to any of the more severe manifestations described above.
What do I do if I think I have an allergy to red meat?
If you develop allergic-type symptoms several hours after eating red meat, then you should see an allergist to get tested. Mild reactions can be treated with antihistamines; an EpiPen can treat more severe reactions. Anyone diagnosed with meat allergies should carry an EpiPen at all times, since meat can sometimes be present in foods where you don't expect it; sometimes just breathing in the smoke from grilled meat can trigger a reaction. If you become short of breath or faint and the EpiPen hasn't brought relief, go to an emergency room.
The good news is that for anyone who has this type of red meat allergy, it appears to be perfectly safe to eat chicken, turkey and fish.
Can I protect myself against developing a meat allergy?
Yes, the same way you can protect yourself against other tick-borne illnesses. When you go outside, make sure you wear layers of tight-fitting clothing and use bug spray containing DEET.
Readers -- Do you allergic to particular foods? How does that affect your daily life? Have you ever suffered from a reaction after eating red meat? Have you ever been to an allergist to get tested? Leave a comment below and let us know.
Dr. Malcolm Thaler is a physician at One Medical Group. He enjoys being on the front lines of patient care, managing diagnostic and therapeutic challenges with a compassionate, integrative approach that stresses close doctor-patient collaboration. He is the author and chief editor of several best-selling medical textbooks and online resources and has extensive expertise in managing a wide range of issues, including the prevention and treatment of cardiovascular disease, diabetes and sports injuries.
Dr. Thaler graduated magna cum laude from Amherst College, received his M.D. from Duke University, and completed his residency in internal medicine at Harvard's New England Deaconess Hospital and Temple University Hospital. He joined One Medical from his national award-winning internal medicine practice in Pennsylvania and was an attending physician at The Bryn Mawr Hospital since 1986. He is certified through the American Board of Internal Medicine.