Understanding Food Combinations: Synergy and Antagonism

In daily life, not all foods can be eaten together. "Proper pairing benefits the body; improper pairing causes illness." In other words, foods can also "antagonize" each other.
Tannins and Protein Antagonism: Eating fruits like grapes, hawthorns, pomegranates, or persimmons simultaneously with seafood can lead to nausea, bloating, abdominal pain, and diarrhea. This is because these fruits contain tannins, which react with proteins in seafood to form insoluble substances difficult to digest. Therefore, after eating seafood, one should wait at least four hours before consuming such fruits. Similarly, avoid drinking tea right after eating meat.
Fiber and Oxalate vs. Iron Antagonism: Animal liver, egg yolks, and soybeans are rich in iron and should not be eaten with high-fiber vegetables like celery, radishes, or sweet potatoes, nor with oxalate-rich greens like amaranth, purslane, or spinach. Both fiber and oxalate hinder iron absorption from these foods.
Protein and Sugar Antagonism: Lysine in milk reacts with sugar under high heat, destroying amino acids. This is why eggs and sugar should not be boiled together. However, if milk is boiled and eggs are cooked until done, then cooled slightly before adding sugar, this issue does not occur.
Carotene and Acetic Acid Antagonism: Avoid adding vinegar when stir-frying carrots, as acetic acid destroys carotene. Likewise, vegetables rich in carotene—such as snow pea greens, spinach, and Chinese cabbage—should not be stir-fried with vinegar.
Oxalate vs. Calcium and Magnesium Antagonism: Avoid eating tofu with spinach. Tofu contains magnesium chloride and calcium sulfate, while spinach contains oxalate. When combined, they form insoluble precipitates—calcium oxalate and magnesium oxalate—that cannot be absorbed by the body. This not only impairs calcium absorption but may also lead to stone formation.