We’ve known for decades that ticks, the tiny blood-sucking arachnids found in tall grass or forests on hikes, carry diseases like Rocky Mountain Spotted Fever and Lyme disease. These diseases pose long-term challenges to our health; the effects of Lyme disease can linger for a lifetime.
New research adds to that litany of threats. Tick bites may also inflict a widely unknown condition that introduces an incurable allergy to red meat.
More specifically, tick bites can cause our body’s immune system to see certain components of red meat as a threat, and attack it. An infected individual may become allergic to commonly enjoyed entrees like hamburgers, steaks, and meatballs.
The condition is called alpha-gal syndrome, and a new study suggests that there may be far more sufferers in the United States than previously suspected. The study reports that the number of cases is on the rise, and diagnoses occur outside the range of the tick species historically associated with this syndrome.
It all starts with a type of sugar molecule that most of us eat almost every day.
Our body hurts us, when it’s trying to help
Our immune system, the collection of many different types of white blood cells that circulate in our bloodstream, constantly works to defend us. These cells monitor for foreign compounds that may indicate the presence of a foreign bacterium or virus. When they find a foreign compound, they synthesize antibodies, custom-designed proteins that stick to the foreign compound. These antibodies act like a homing beacon for other parts of the immune system, which eat and destroy anything that’s got antibodies sticking to it.
Loggers often mark diseased trees with spray paint on the trunks to indicate that they need to be removed. In a similar manner, antibodies help our body determine which cells are invaders; when they stick to a cell, it’s an indicator for our immune system to destroy that cell.
The trouble is that our body isn’t perfect when it comes to identifying invasive substances. Sometimes our immune system overreacts to a harmless substance and marks it as dangerous, producing antibodies to stick to that substance and leading to an immune overreaction. These overreactions are more commonly called allergies.
In alpha-gal syndrome, the human immune system overreacts and makes antibodies against a molecule called galactose-alpha-1,3-galactose (alpha-gal), which is found in red meat, but also is in the saliva of several different species of ticks. Galactose is a type of simple sugar, so alpha-gal is made of two galactose sugars linked to each other.
After an initial exposure, our immune system mistakenly sees alpha-gal as an indication of foreign invaders. It ramps up in defense against an invisible enemy, causing a range of symptoms:
- Hives
- Stomach pain
- Diarrhea
- Vomiting
- Nausea
- Anaphylactic shock, a whole-body reaction that can cause our blood pressure to drop, fainting, and trouble breathing as our throat swells shut
The only documented deaths from alpha-gal syndrome came from patients who, not knowing they had the condition, received an experimental cancer treatment that included the alpha-gal molecule. But even non-fatal immune reactions are unpleasant.
How ticks are connected with red meat
Ticks don’t directly produce alpha-gal. Instead, they pick it up from many of their common prey. Alpha-gal is present in the blood of a number of different mammals, including cows, sheep, and deer.
When a tick jumps to its prey, it injects a barbed harpoon-like structure into their skin to drink blood, its sole food source. It pushes spit into that wound, which contains anti-clotting factors to keep the blood flowing freely.
If that tick previously ate from an animal with alpha-gal in its blood, traces of alpha-gal remain on its harpoon and in its saliva. When a tick pushes its spit into a person to keep the blood from clotting, it may also transfer alpha-gal from its last victim.
A wide range of commonly consumed mammals produce alpha-gal; it’s in both the blood and the meat of cows, pigs, sheep, deer, and rabbit; it’s also present in their milk and cheese. Even gelatin, commonly made from the cartilage of mammals, can contain enough alpha-gal to trigger an allergic reaction.
It’s challenging to say how frequently a tick bite that deposits alpha-gal can lead to an allergic reaction. Some people’s immune systems won’t react to the molecule at all, even if they’re bitten several times by ticks. But repeated exposures, such as from multiple tick bites, seem to increase the chances of developing an allergy.
This allergy can be difficult to diagnose in its sufferers. When humans consume red meat, the alpha-gal doesn’t immediately absorb into the bloodstream, so they may not show symptoms of the allergic reaction until hours after the meal.
There’s no cure, but we can take steps to protect ourselves
Like other allergic reactions, alpha-gal syndrome, once it’s contracted, is a lifelong condition. The only way to avoid symptoms is to avoid the triggers: no red meat and minimizing dairy products. (Fish and avian products, like chicken and eggs, don’t contain alpha-gal and are fine to consume.)
For those who are uncertain but suspect they may have alpha-gal syndrome, the best choice is a blood test that a doctor can order to check for a reaction. The specific test name is an alpha-Gal specific IgE component test.
Many doctors are unfamiliar with alpha-gal syndrome, which is why recent articles have hypothesized that the condition is present far more commonly than diagnoses would suggest. It has also been diagnosed around the globe, in Brazil, South Africa, Australia, Korea, Japan, and throughout Europe.
The best move: prevention. Take steps to avoid tick bites in the first place.
Ticks live in grassy or wooded areas, and can hitch rides on clothing and pets. Before going out, you can apply DEET bug repellant and treat clothing with an insecticide called permethrin. After returning indoors, you should change clothes and wash the old ones; 10 minutes of high-heat tumble-drying will kill ticks on dry clothes. It’s also recommended that you shower (you’d want to wash the hiking dirt and sweat off in any case!) and check yourself for any attached ticks. Make sure to check hard-to-reach areas, like the backs of knees, armpits, groin, belly button, behind the ears, and in and around your hair.
Some biting tick relatives, called chiggers (or berry bugs or harvest mites) can also transmit alpha-gal, and can be smaller than a poppy seed. For difficult-to-detect creatures such as these, the best move is using bug repellent or insecticide to prevent them hopping on at all.
A new reason to maintain vigilance against ticks
Ticks thrive in warm and humid conditions; thanks to climate change, their habitats are expanding in the United States, reaching further north than before. Multiple species of tick can carry alpha-gal in their spit, picked up from the blood of previous prey. Areas of the United States and Europe that previously didn’t see much tick activity are now under threat, and many hikers may be ill-prepared.
Currently, the only treatment is a lifelong avoidance of red meat and dairy products. The best move is to be aware and vigilant against ticks, applying preventative bug spray, wearing treated clothing when hiking in tick-infested areas, and carefully screening post-hike for any unwanted pests.
Regardless of recent tick bites, if you think you have a red meat allergy, talk to your doctor to schedule a blood test! Just keep in mind that you may need to encourage your doctor to read up on alpha-gal syndrome as well.
Thanks for reading! Next, check out whether a testosterone supplement could turn a Democrat into a Republican (quick answer: no, but it’s complicated)