Bill Blackley is a family practice doctor, an avid hiker, and a volunteer organizer for Mountains-to-Sea Trail in North Carolina. In 2015, he contracted Alpha-gal syndrome, a little-known meat allergy that is spread by ticks. Alpha-gal causes many debilitating symptoms including an anaphylactic response that can be extremely dangerous. Dr. Blackley shares his experience and the ways he has found relief.
Question: If all red meat (beef, lamb, pork) has alpha gal in it, why don’t people have an allergic reaction when they eat meat unless they are exposed to alpha gal through a tick bite?
Answer: “A tick bite triggers your immune system to react to alpha-gal as a defense mechanism. The antibodies that your body makes to protect you from the tick bite remain in your system. These antibodies will then combat alpha-gal when you eat meat that contains it.” (source: Healthline.com)
Here’s more detail from alpha-gal expert Scott Commins, MD, who is mentioned in the interview:
“It’s a fascinating question overall for the field of allergy / immunology: why does one route of exposure induce tolerance (oral) while another leads to allergy (skin). It’s an active area of research for food allergy in general and obviously for [alpha-gal researchers].
Basically there are two factors: one is the route of exposure. Absorption through the gut leads to tolerance, which is why the overwhelming majority of people do not have an allergic response to foods. On the contrary, exposure through the skin is an established way to drive an allergic response. This leads to the second factor: tick saliva. Tick spit is highly and by being “applied” through the skin, this causes the human immune system to make an allergic response to the alpha-gal present in some ticks.
What becomes impressive, to me anyway, is how powerful the tick saliva factors are that these can create an allergic response to alpha-gal when a tolerant response is already in place. More directly: most folks with AGS have safely eaten red meat for years and yet a tick bite can overcome that to drive a “new” allergic response.”