2. The brain in duck head is a good thing, and its scientific name is duck brain. Cholesterol is high, and vitamins E and B are also rich. Fresh duck brains are sweet and juicy, but old duck brains should not be eaten as much as possible because of bacteria and toxins. Moreover, the nicotinic acid in the head of an old duck is destroyed, which produces a protease harmful to human body, so try not to eat the brain pulp in the head of the duck, especially the old duck.