That midnight grilled cheese might be coming back to haunt you, literally.
A recent study published in Frontiers in Psychology has found a notable link between food sensitivities, particularly lactose intolerance, and the severity of nightmares. Researchers believe that the gastrointestinal distress experienced by those with food intolerances during the night may disrupt sleep and sneak its way into their dream life.
“Nightmare severity is robustly associated with lactose intolerance and other food allergies,” Dr. Tore Nielsen, lead author of the study and director of the Dream and Nightmare Laboratory at Université de Montréal, told Newsweek.
“These new findings imply that changing eating habits for people with some food sensitivities could alleviate nightmares. They could also explain why people so often blame dairy for bad dreams!”
The research team surveyed 1,082 university students at MacEwan University in Alberta, Canada, collecting data on sleep patterns, dream content, physical health, mental wellness, and dietary habits. Nearly a third of participants reported frequent nightmares, with women significantly more likely than men to recall dreams, report poor sleep, and experience unsettling dream content.
When participants were asked whether they believed food affected their dreams, either by worsening or improving them, approximately 40% said yes, mainly when they ate late at night. Around 25% believed that certain foods actively worsened their sleep quality, with sweets (31%), dairy products (22%), meats (16%), and spicy dishes (13%) topping the list of culinary culprits.
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Notably, women were also almost twice as likely to report food allergies or intolerances. Of the people who believed their diet was related to worsened sleep, 30% were lactose intolerant.
Despite this, only 5.5% of participants reported that food influenced the emotional tone of their dreams in addition to quality. Still, among that group, dairy products, particularly cheese, were frequently mentioned as triggering strange or distressing dreams.
The findings might help address some of the issues brought up by a 2015 study that examined the variables influencing “food-dependent dreaming,” or how food influences dreams.
“In the earlier study, people were blaming cheese all the time for their bad dreams. And so I think we got some better answers in the study for that.”
The association may be rooted in how the body processes dairy during sleep. For individuals with lactose intolerance, consuming cheese or milk products before bed can lead to bloating, cramps, and other gastrointestinal symptoms. That discomfort may disrupt sleep and feed into negative or bizarre dream content.
“Nightmares are worse for lactose-intolerant people who suffer severe gastrointestinal symptoms and whose sleep is disrupted. This makes sense because we know that other bodily sensations can affect dreaming. Nightmares can be very disruptive, especially if they occur often, because they tend to awaken people from sleep in a dysphoric state. They might also produce sleep avoidance behaviors. Both symptoms can rob you of restful sleep.”
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The findings provide a possible scientific explanation for an age-old folk belief that eating cheese before bed can lead to bad dreams. While the notion has existed for centuries, concrete evidence has been elusive until now.
According to the USDA’s Agricultural Research Service, 68 percent of U.S. adults consumed cheese on any given day in 2017–2018, whether as a snack or an ingredient. While cheese can contribute to calcium intake and even promote oral health, the timing of its consumption may be more important than many realize.
Interestingly, fewer students today seem to associate food with dreaming than a decade ago. Nielsen and co-author Dr. Russell Powell noted that in the prior 2015 study, more participants linked specific foods with dream outcomes. They speculate that growing awareness of food intolerances may lead people to avoid known trigger foods altogether, thus reducing the chance of sleep disruption in the first place.
While the researchers emphasize that the correlation between food and dreams is still complex and not fully understood, they do see potential in dietary adjustments to support better sleep. However, they stop short of making universal recommendations.
A poor diet might lead to poor sleep, and vice versa—or there could be a third factor we haven’t identified yet, Nielsen suggested to Newsweek.
“We need to study more people of different ages, from different walks of life, and with different dietary habits to determine if our results are truly generalizable to the larger population. Experimental studies are also needed to determine if people can truly detect the effects of specific foods on dreams. We would like to run a study in which we ask people to ingest cheese products versus some control food before sleep to see if this alters their sleep or dreams.”
Of course, not every food is associated with nightmares and disturbed sleep; in fact, certain foods may actually promote better sleep. 13% of those who drink herbal tea, 12% of those who eat a lot of veggies, and nearly 18% of those who regularly eat fruits reported having better sleep.
Moumita Basuroychowdhury is a Contributing Reporter at The National Digest. After earning an economics degree at Cornell University, she moved to NYC to pursue her MFA in creative writing. She enjoys reporting on science, business and culture news. You can reach her at moumita.b@thenationaldigest.com.
