Meat allergy is becoming more common. Ticks are being blamed
"Many older deer hunters are a little taken aback when they have to stop eating red meat," says a senior consultant and researcher.
The castor bean tick, which is common in Europe, may also carry the substance that can trigger an allergy to red meat.(Stock photo: KPixMining / Shutterstock / NTB)
Meat allergy is becoming more common in several parts of the world, according to Nature News. And the suspected culprit comes as a surprise to many: ticks.
"There are two ways in which ticks can make you allergic to red meat," says Marie Alnæs.
She is a senior consultant and researches allergies at Haukeland University Hospital.
Unlike typical tick-borne diseases such as Lyme disease and TBE, this condition is not caused by bacteria or viruses.
Instead, it is linked to a type of sugar called alpha-gal. Ticks can expose you to this sugar in two different ways.
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"One is that the tick produces the substance itself, and the other is that it picks it up during an earlier blood meal from another animals," says Alnæs.
Alpha-gal is a sugar found in meat
But how can a sugar make you allergic to red meat?
Alpha-gal is actually a common sugar found in meat from mammals such as pigs, cows, and sheep, Alnæs explains.
Under normal circumstances, your body does not react to this sugar when you eat something like a steak. Instead, it is broken down in the digestive system like most other things you eat.
Marie Alnæs researches allergies at Haukeland University Hospital.(Photo: Private)
Why the body develops an allergic reaction to alpha-gal
But if you are bitten by a tick carrying alpha-gal, the substance enters directly into your bloodstream. Your body may then perceive it as a threat.
Your immune system produces antibodies that recognise alpha-gal. The next time you eat red meat, these antibodies can trigger an alarm response in your body a few hours later.
But there are major differences in how severe the allergy becomes, Alnæs explains.
"A small number of people can develop a severe systemic reaction, known as anaphylaxis, after eating only a small amount of red meat. Others may simply experience mild stomach pain, some hives, or a little itching," says Alnæs.
The man, who had previously been healthy and had no history of allergies, later said that he had received over 20 tick bites two months earlier. When he also confirmed that he had eaten red meat on the day he became ill, doctors began to suspect a connection.
They tested his blood for antibodies. Sure enough, he had developed an allergy to alpha-gal.
"Deer hunters are a little taken aback"
There are no figures showing exactly how many people in Norway have this allergy. But Alnæs has encountered several older patients with meat allergies at Haukeland University Hospital.
"In western Norway, there are an awful lot of ticks, and also many deer hunters," says Alnæs.
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Deer have also moved closer to populated areas because natural habitats are being developed. And where the deer go, the ticks follow.
"Many older deer hunters are therefore a little taken aback when they have to stop eating red meat," says Alnæs.
In a 2023 study, American researchers at the CDC estimated that up to 450,000 Americans have this type of meat allergy.
Most cases are found in areas with lots of ticks. In some parts of the United States, enough people have been affected that stores and restaurants have had to adapt. CNN discusses this in the following video:
Doubling in Denmark
Figures from Denmark and Sweden suggest that Norway could also see more cases of meat allergy caused by tick bites in the years ahead.
In a Danish study, researchers examined blood samples from 11,000 people. They found that the proportion of Danes carrying antibodies associated with red-meat allergy had doubled.
In 1990-1991, 1.3 per cent of Danes had these antibodies in their blood. By 2016-2017, the figure had risen to 3.2 per cent.
At the same time, it is worth noting that 97 per cent of the Danes who had this sensitivity reported eating at least one meal containing red meat every week.
So it appears that most people experience relatively few symptoms.
Thinks doctors have become better at testing for it
The link between tick bites and meat allergy is relatively new knowledge.
Because of this, some of the more serious cases may previously have gone under the radar, according to Alnæs.
Even so, she believes the situation is beginning to change.
"I think many doctors have become better at remembering that they can test for it," says Alnæs.
