Drinking cow’s milk produced at night may be a treatment for anxiety and insomnia, suggests an animal study in the Journal of Medicinal Food.

A glass of milk at bedtime has long been touted as a sleep aid. But the study found that milk collected at night, or night milk, had enhanced sedative effects in mice compared with milk produced during the day. Night milk significantly decreased the rodents’ physical activity, balance and coordination and increased sleep time compared with day milk, the research showed.

Mice...