Soymilk is not poisonous and is a nutrient, but it can be bad for you if you don't combine it with other nutrients. Soy milk contains phytoestrogens, which may elevate the risk of breast cancer. So if you have a family history of breast cancer, you need to consult your doctor about whether milk can be drunk with soy milk.

Washing soy milk with eggs. When eggs are paired with soy milk, the mucilaginous proteins in the eggs tend to bind intimately with the razor proteinase in the soy milk, producing a substance that simply cannot be absorbed. Add brown sugar. The organic acid in brown sugar combines with the protein in soy milk to produce a denaturing precipitate that can break down and destroy the nutrients in brown sugar and soy milk. However, adding white sugar to soy milk will not produce the above chemical reaction.