To Be or Not To Be a Vegetarian: That is the Question. Or is it?
Most people see a documentary about the meat industry
and then they become a vegetarian for a week.
– Jason Reitman
Guilty. as. charged.
After seeing Food, Inc. in college, I gave up meat for idealistic reasons. A week later, I was scarfing down bacon with cheese grits during a late night Snelli-bration. Despite the gruesome images plastered in my mind from the documentary, I could not resist the salty goodness that was tempting my tastebuds from across the dining hall.
I like to think that my willpower has strengthened with age, but truthfully I don't have enough toes and fingers to count the times I've sworn off meat only to find myself pigging out at a BBQ or gnawing on a jumbo turkey leg at a renaissance festival. So what makes it so hard for me to go full veg? My stints as a vegetarian always end with this thought: Maybe, just maybe, I could be a vegetarian if meat weren't so damn delicious!
If only the sight of a browned Christmas ham made me want to gag. Or the very thought of a perfectly seared, medium-rare filet mignon repulsed me. If only ingesting lamb kabobs made me ill. Maybe then I could finally become a vegetarian.
Sadly for the idealistic version of myself and thankfully for my stomach, there's nothing about a Christmas spread that makes me want to gag and I don't find a juicy, red steak sickening. Quite the opposite actually…
Who has two thumbs and loves meat? This gal! (Photos courtesy of my iPhone)
I love meat, and eating pork and beef is a choice for me. On any given day I can ask myself, “Will I have tofu or steak?†But for others, like Tygh Walters, the choice between tofu and steak is one of life and death. That's because developing a meat allergy is a real thing and might have some merit as a weird way to force oneself into a (somewhat) vegetarian lifestyle.
Mammalian Meat Allergy
If you have experienced a food allergy yourself or witnessed a friend or family member experience one, then this scenario may sound all too familiar: after eating an allergen-containing food, itchy hives pop up all over your skin, you swell up like a balloon, and you might be keeled over with horrible stomach pains akin to those described on a Pepto commercial.
I have friends and family with food allergies to nuts, berries, gluten, citrus fruits… you name it, they have it! But, Tygh is the first person I've met with a food allergy to mammalian meat, called Mammalian Meat Allergy (MMA). One subtle difference with MMA compared to other food allergies is the delayed onset of symptoms. For example, when a person with a peanut allergy eats a nut, symptoms like life-threatening anaphylaxis are instantaneous. When a person with MMA eats a steak dinner, however, the symptoms may not appear until 4-8 hours after the meal. In Tygh's case, he describes his first reaction to meat after experiencing Texas BBQ during a business trip to Austin:
I ordered a whole pound of beef brisket – it was like a mini bucket. That's way too much, but I ate the whole thing and was very full. Six hours later as I was stepping off the plane, I was itchy. It started on my head and around the waistband of my pants. I pulled my shirt up and I had welts everywhere. My first thought was the hotel room had bed bugs, but it started to occur to me that this was more globalized than bug bites – it was a systemic thing. I popped some antihistamines when I got home and thought nothing of it. It was weird.
Hives all over! – an allergic reaction to meat (Photos courtesy of Tygh Walters)
The delayed onset of symptoms can distinguish MMA from other food allergies. However, the main difference between MMA and other food allergies is the fact that the allergen that triggers this reaction is a sugar rather than a protein.
Alpha-Gal Meets Meat Allergy: A Sugary Connection
Alpha-Gal may sound like a kickass female superhero name, but it's actually the nickname of the sugar behind this strange meat allergy. Galactose-alpha-1,3-galactose (or alpha-Gal, for short) is found in all mammals except for old world monkeys, apes and humans. Primates, like us humans, lack a working version of the enzyme that makes alpha-Gal (called alpha-1,3-galactosyltransferase), so they do not produce this sugar.
So what does this mean for us meat-consuming humans? Because we don't produce alpha-Gal, our bodies recognize alpha-Gal as foreign (i.e. not self). In the absence of alpha-Gal on our tissues, our immune system produces antibodies against it. Antibodies are like our body's surveillance system, constantly scanning the surroundings for intruders and foreign objects. Once an antibody specific for alpha-Gal captures the foreign sugar, it will attach to receptors on white blood cells that act as our bodies defenders. With a signal from the antibodies that intruders are in their midst, the white blood cells release ammo in the form of granules that contain histamine. The release of histamine causes the familiar symptoms associated with an allergic reaction.
Lucky for us meat lovers out there, antibodies that recognize alpha-Gal are normally present in our bodies in very small amounts so we can happily enjoy a cheeseburger if we so choose. The fact that non-mammalian meat sources like poultry and fish do not produce the alpha-Gal sugar also means that everyone can keep enjoying all the chicken and salmon their hearts desire without fear of going into anaphylactic shock. So why do people like Tygh have a severe allergic reaction to red meat and pork if all of us are producing these antibodies against alpha-Gal?
Meat Allergy: A Ticking Time Bomb For Some
Researchers wanted to answer why alpha-Gal triggers an allergic reaction in certain individuals, so they started looking for trends among those affected. Most cases were regionalized in the central and southern US, which coincides with high incidences of Rocky Mountain Spotted Fever. This area also happens to be the habitat of the Lone Star tick. This is when the dots started to connect, becuase most affected individuals noted extensive outdoor activity and a few mentioned tick bites that had occurred weeks prior to their onset of symptoms. For Tygh, a specific camping trip at South Cumberland State Park in Tennessee stands out as a pivotal point in his experience with MMA:
I ventured off the trail into the woods to look for cool plants and flowers, thinking nothing of it. Later that evening I got really itchy around my waistband… I never found a tick, but what I did have was dozens of bites around my waistband. That event was very significant because my MMA started happening after that.
So how can a tick bite lead to a meat allergy? Or in Tygh's words, “I ingested [meat] my entire life, so why now?â€
Imagine a tick feasting on the blood of a deer. After this meal, the tick's digestive tract contains our star sugar, alpha-Gal. Our fat, happy tick falls off the deer somewhere in the woods where it rests until its next meal. A few days later, the now famished tick hops onto an unassuming human who is enjoying a hike through the woods. When the tick bites the human, it gives rise to an immune response. The antibodies responsible for the response may be created because of residual alpha-Gal from the tick's venison meal, something in the tick's saliva, or an unknown bacteria living inside the tick. Once enough antibodies build up in the human, the consumption of alpha-Gal-containing meat induces an allergic reaction.
Finally Cured of My Love for Meat? More Like A Huge Missed Steak
For some, abstaining from eating meat is a moral choice, while for those suffering from MMA it has become a life-saving necessity. As Tygh puts it, “If I accidentally eat a massive amount of meat, I could die.†There is no cure per se, but luckily for those currently suffering from MMA, there is a chance that the allergy will dissipate over time (so long as more tick bites are avoided). For some, like Tygh, their brush with an MMA-causing tick has its positives:
Fortunately for me though, when it comes to food, I'm not really picky. I was never into steaks and burgers anyway. So the lifestyle change hasn't been that drastic… As an unexpected consequence, it's unintentionally pushing me towards an arguably more ethical way of eating because, yeah, I can eat chicken and fish, but I've noticed myself ordering more vegetarian options. From a health and wellness standpoint, vegetarian diets are superior. I know that intellectually, but I just never had the motivation or guts to see it through.
Sounds like MMA just might be what this carnivore needs to finally force myself into a vegetarian lifestyle! With that said, I think I will continue to savor steak, lamb kabobs and the joys of the great outdoors while I can. Until the day I become one of the unassuming humans bitten by a meat allergy-inducing Lone Star tick, the meat I choose to eat will simply taste all the more sweet. For the time being (and for the love of meat), I wish you all bon appetit!
For more information on alpha-Gal and MMA check out the following:
http://www.sciencemag.org/news/2012/11/ticked-about-growing-allergy-meat
http://www.cnn.com/2012/06/20/health/meat-tick-bite-allergy/
About the Author:
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Stephanie M. Halmo is a former middle school science teacher turned graduate student, actively pursuing her Ph.D. in biochemistry from the University of Georgia. In her spare time she likes to dance, volunteer at local schools and tie-dye anything she can get her hands on. She is currently ASO’s News Editor. You can connect with Stephanie on Twitter and Instagram @shalmo or by email: shalmo27@uga. More from Stephanie M. Halmo. |
