Snacking on cheese late at night may haunt your dreams, Canadian study finds
A new Canadian study has found that a late-night cheese snack could lead to nightmares.
The study, published in psychology journal Frontiers on June 30, looked at the link between food, sleep quality and dreams.
It revealed that just over 40 per cent of participants said eating certain foods affected their sleep, with nearly a quarter saying some foods worsened sleep. A small group of participants, 5.5 per cent of them, said food even affected their dreams.
The culprit for both pleasant and disturbing dreams? Dairy.
It was most frequently identified as the food category with the most influence. When it came to nightmares, researchers found that a contributing factor was lactose intolerance. That could explain why munching on cheese before catching some Zs led to bizarre, disturbing dreams for some.
According to the study, it’s possible that gastrointestinal (GI) symptoms increase nightmares by “increasing symptoms of anxiety and depression,” which can also impact sleep quality.
As well as dairy, other types of foods linked to nightmares were sweets, meat and spicy foods.
The belief that food can affect dreams goes back centuries, based on old tales and anecdotal evidence, the study explained. One such example, cited in the study, is a cartoon by artist Winsor McCay , showing a character that blames eating cheese before bed for bizarre dreams and nightmares.
“Although we had predicted that lactose intolerance might be related to dreaming… we were a bit skeptical and we certainly weren’t expecting to see the relationship to nightmares to be so robust,” the study’s lead author Dr. Tore Nielsen told National Post over email on Wednesday.
Nielsen said, in a Frontiers news release , that it makes sense for lactose intolerant people who suffer from GI symptoms and disrupted sleep to have worse nightmares “because we know that other bodily sensations can affect dreaming.”
“Nightmares can be very disruptive,” he said, “especially if they occur often, because they tend to awaken people from sleep in a dysphoric state. They might also produce sleep avoidance behaviours. Both symptoms can rob you of restful sleep.”
Nielsen, a University of Montreal psychiatry professor and director of the Dreams and Nightmares Laboratory, told National Post that researchers also didn’t expect to see a link between food allergies and nightmares.
Participants with food allergies and gluten Intolerance were more likely to report that food affects dreaming, while those with lactose intolerance were more likely to report that food causes worse sleep, per the study. Those with food allergies may be “more sensitive and attuned to what they eat,” the authors wrote, making them more likely to attribute dream changes to diet.
Meanwhile, having pleasant dreams was linked to eating fruits and vegetables and drinking herbal tea, as well as desserts and dairy.
Researchers linked an unhealthy diet, in general, to nightmares. “An unhealthy diet included eating in the evening before bed and not paying attention to internal cues about being hungry or full in deciding when or how much to eat,” Nielsen told National Post.
“It is possible that people with nightmares could find some relief not only by checking on their lactose intolerance and food allergy status and dosing their intake of the problematic foods accordingly, but by following a healthier diet.”
Although the study’s authors said that they still “lack substantive evidence that these participant observations for food and dreaming are, in fact, accurate, there is some suggestive evidence for their accuracy.” The study’s findings show how diet could inform interventions for sleep disturbances that don’t rely on medication.
Although the latest findings uncovered some answers, there is still a need for more research, including studies to find out if people can truly detect the effects of specific foods on dreams, Nielsen said in a Frontiers news release .
There were 1,082 participants in the study, who were all undergraduate students at MacEwan University. The data was collected online from January to April 2023. The study’s authors noted that those who took part could have been biased due to having academic exposure to related topics that influenced how they interpreted or reported the perceived effects of food on sleep and dreaming.
One study published in 2022 in the International Journal of Dream Research observed whether or not substances and foods had any effects on dreams and lucid dreams (the person is aware they are dreaming). It found that eating fruits correlated to dream recall, while eating fish correlated with the frequency of lucid dreams. However, it determined that research on the topic is “scarce” and more testing is needed.
In 2005, the British Cheese Board said that different kinds of cheese can influence dreams based on the group’s own research. In an interview with NPR , the board’s secretary Nigel White said that although some people had “wacky” dreams, none of the volunteers who took part in the survey had nightmares.
As well as Nielsen, researchers from the University of British Columbia in Vancouver and Grant MacEwan University in Edmonton co-authored the study.