Eating a lot of dairy products such as cheese or milk before bed may increase the likelihood of having nightmares, according to new research. On July 1 (local time), a research team from the University of Montreal in Canada published their findings on the connection between food and sleep in the international journal Frontiers. The study surveyed 1,082 students at MacEwan University in Canada about their sleep duration and quality, dream frequency, mental and physical health, and any associations between specific foods and their dreams. According to the results, 40.2% of respondents said that eating late at night affected their sleep, and 24.7% of those reported that certain foods worsened their sleep quality. The foods most commonly cited as disruptive to sleep included snacks, spicy food, and dairy products. Additionally, 5.5% of participants said they believed the food they ate influenced the content of their dreams. Among them, many reported more disturbing or bizarre dreams after consuming sweet or dairy-heavy foods.

The researchers explained that excessive intake of dairy products can lead to gastrointestinal discomfort in individuals with lactose intolerance, which may negatively affect sleep. The discomfort from digestive issues may even influence dream content, ultimately degrading overall sleep quality. Dr. Tore Nielsen, the study’s lead author, noted, “Nightmares were more pronounced in individuals with lactose intolerance who experienced digestive and sleep issues. This may be because other physical sensations can influence dreams.” He added, “Nightmares appear to be closely related to lactose intolerance and other food allergies. Our findings suggest that adjusting dietary habits could help reduce nightmares in people sensitive to certain foods.” However, the researchers emphasized that more studies are needed to generalize the findings. Dr. Nielsen stated, “We plan to conduct experimental studies involving people from more diverse age groups, backgrounds, and dietary habits. This will include examining whether consuming dairy or control foods before bed leads to changes in sleep or dream patterns.”

(The Dong-A Ilbo, July 7, 2025)