I am very HIGHLY allergic to grass and trees, specifically meadow fescue, which is what grass-fed beef are supposed to be fed on. If I eat grass-fed beef, will I have an allergic reaction to the grass the cattle ate?
Its a difficult question to answer, personally my thoughts would be it is unlikely. There is a condition known as pollen food syndrome which can occur in people who are allergic to pollen from trees, grasses or weeds. Pollens from trees, grasses and weeds contain proteins of similar structure to those present in different fruits, vegetables, nuts and spices. These proteins are recognised by the immune system and can trigger an allergic reaction in a susceptible person. However in the case of grass fed beef, the allergenic proteins in grass would be broken down during the digestion process of the cattle eating the grass. These allergens would be broken down to their constituent amino acids and would never make it into the beef itself. Theoretically if these proteins were still able to make it through the digestion process and were still intact in the in the beef, cooking the beef thoroughly at a high temperature would break the structure of the proteins down. Once the allergen (the specific protein structure) has been broken down it will no longer be recognised by the immune system. Examples of this can be found in people with dairy allergies, they cannot drink fresh milk, but once the milk has been boiled (and the allergenic proteins broken down) they have no problem. Of course this does not apply to everyone and this simplistic approach cannot be taken across the board. If you do have severe allergies, I would always suggest discussing with your doctor or allergy specialist, before making any additions to your diet.