Galactose-alpha-1,3-galactose is popularly known as alpha-gal. It is a carbohydrate found in the meat of mammals – exceptions being primates (which includes humans) and other African and Asian apes.
Galactose is a simple carbohydrate that is found in mammal milk. Alpha-gal is formed from a combination of two galactose molecules.
When our immune system recognise a foreign entity, it create antibodies an attempt to destroy the invader. There are five classes of antibodies found blood serum: IgG, IgM, IgA, IgE and IgD. IgG antibodies to alpha-gal are very common in humans as a result of continuous consumption of alpha-gal via red meat.
Since the early 2000s, severe allergic reaction has been observed several hours after the consumption of red meat. Several deaths have occurred. This is associated with IgE (not IgG) antibodies to alpha-gal as a result of the patients been bitten by ticks. This has occurred in eastern Australia, south-east USA and Sweden.
Alpha-gal is similar to the blood group B antigen. As a result, there is an association with the patients with B blood group and red meat allergy.
- Apostolovic, D. et al. (2015) Red meat allergic patients have a selective IgE response to the α-Gal glycan. Allergy. 70 (11), 1497–1500.
- Apostolovic, D. et al. (2016) The red meat allergy syndrome in Sweden. Allergo Journal. 25 (2), 29–34.
- Larsson, S. C. & Orsini, N. (2014) Red Meat and Processed Meat Consumption and All-Cause Mortality: A Meta-Analysis. American Journal of Epidemiology. 179 (3), 282–289.
- Steinke, J. W. et al. (2015) The alpha-gal story: Lessons learned from connecting the dots. Journal of Allergy and Clinical Immunology. 135 (3), 589–596.