The misunderstanding between eggs and soy milk first originates from trypsin inhibitors found in soybeans, which are substances that can inhibit trypsin from its function of digesting protein. Therefore, rumor-mongers believe that when soy milk and eggs are eaten together, the trypsin inhibitors in the soy milk will make the protein in the eggs difficult to absorb.
In fact, all soy milk must be cooked before drinking. As long as the soybeans are cooked, the trypsin inhibitors are destroyed and cannot play a role in inhibiting the absorption of egg protein.
Supposing this trypsin inhibitor existed and was not destroyed, it would not only inhibit the absorption of egg protein but also the absorption of soy protein. In this case, soy milk containing trypsin inhibitors, when eaten with any protein-containing food, would cause so-called "incompatible reactions".
Another saying about the misunderstanding between eggs and soy milk is: "The avidin in eggs combines with the trypsin in soy milk to form an indigestible substance, greatly reducing its nutritional value." This is a completely baseless claim. Raw soybeans contain trypsin inhibitors, not trypsin. Trypsin is secreted by the pancreas.
Eating eggs, soy milk, and milk together is not only very safe but also highly nutritious.