Explanation:
It is said that the tannic acid of persimmon will combine with the protein of crab (or other food with high protein content), causing poisoning.
Refutation 1: Persimmon has extremely low tannin content, which is not unique to him. If you eat it, you will be poisoned like other fruits.
Refutation 2: Tannic acid can promote digestion, and it will only be more easily absorbed by protein. . .
So, it's totally bullshit. Previous experience misled people, because persimmons and crabs are special products at the same time every year and were wrongly associated by the ancients.