Montreal: Cheese might not directly cause nightmares, but your gut health could be to blame. A new study published Tuesday in Frontiers in Psychology suggests that people with severe lactose intolerance symptoms are more likely to experience intense and distressing dreams.
Researchers surveyed over 1,000 university students about their eating and sleep habits. They found a strong link between gastrointestinal issues from dairy and the frequency and severity of nightmares. Participants with worse lactose intolerance symptoms reported more disturbing dreams, lasting longer, causing more anxiety, and interfering with daily life.
While cheese was the most blamed culprit, sweets were also commonly linked to bad dreams. Professor Tore Nielsen, a sleep researcher at the University of Montreal and study co-author, said the findings offer more clarity than past research, including a 2015 study that explored “food-dependent dreaming.”
The connection may stem from how digestive issues disrupt sleep. Columbia University sleep specialist Marie-Pierre St-Onge noted that gastrointestinal discomfort often leads to sleep disturbances, which may trigger vivid or unpleasant dreams.
Patrick McNamara, a neurology professor at Boston University, added that consuming dairy could cause “micro-arousals”—brief awakenings during sleep that lower sleep quality and increase the chance of nightmares.
However, researchers caution that other factors, such as anxiety or individual differences, could influence the results. Since the participants were students in an introductory psychology class, the findings may not apply to everyone.
Study co-author Russell Powell, professor emeritus at MacEwan University, said they hope to replicate the research with broader groups. Meanwhile, Nielsen recommends that people observe how their diets affect their sleep and make simple changes as needed, without always needing professional help.
