Milk as a food generally does not exist when to drink the effect is good, middle-aged and elderly people can drink milk before going to bed, but also as breakfast to drink. Milk contains tryptophan, tryptophan in the human body can be synthesized with other substances to synthesize pentazocine, pentazocine has the role of helping sleep, so a glass of milk before going to bed, may help sleep. Milk is rich in calcium, drink milk before going to bed, can also supplement the loss of calcium at night when sleeping, and then play a role in protecting the bones. It should be noted that if middle-aged and elderly people suffer from diseases and need to drink medicine at night, they should not take the medicine with milk, so as not to affect the efficacy of the milk, which is not conducive to the body’s absorption of the drug. You can choose to use the milk as breakfast or add meals. In summary, before going to bed can drink milk, but note that excessive drinking milk at night may increase the number of urination, but is not conducive to sleep; you can also choose to drink milk for breakfast, a moderate amount every day.