Science: Ticks are more likely to cause red meat allergies than we thought

We like to imagine that being bitten by a bug will give us cool, arachnid-based super powers — not food allergies.

But evidence has shown bites from certain species of ticks can lead to a temporary allergy to alpha-gal, a sugar found in red meats like beef, lamb and pork. Scientists have said that the allergy is more likely to be triggered if the offending tick had recently fed on alpha-gal-rich mammal blood, but new research suggests that this is not the case.

“Our original hypothesis was that humans developed the allergy after being exposed to alpha-gal through a tick that had fed on a deer, dog or other small mammal that has alpha-gal,” said Dr. Scott Commins of the University of North Carolina. “This new data suggests that ticks can induce this immune response without requiring the mammal blood meal, which likely means the risk of each bite potentially leading to the allergy is higher than we anticipated.”

In a lab, Commins and his team stripped white blood cells of certain antibodies produced during allergic reactions: Immunoglobulin E. The cells were then primed with plasma from people with and without alpha-gal allergies. After that, tick salivary gland extract was added. Some of the ticks had recently fed on blood containing alpha-gal, but not all.

Surprisingly, allergic reactions were triggered regardless of whether the ticks had fed on alpha-gal blood or not. The researchers reported that saliva from a Lone Star tick, a species closely associated with the allergy, caused reactivity 40 times higher than the control.

“These results suggest that more tick bites than we initially suspected could pose a risk for developing red meat allergy,” Commins said.

People who develop the allergy have to avoid red meats for about three to five years, when the allergy tends to disappear (provided there are no other tick bites). Some bite victims have reported being unable to eat other animal products, like cheese, or wear wool clothing.

Experts have said that tickborne illnesses in general are likely to increase in the U.S. over the next few years. Wearing long sleeves and pants outdoors, using insect repellent with 20% more of DEET, picaridin or IR3535, and checking your body for tick stowaways can help protect you.