The findings of a new study suggest that the age-old belief that eating cheese before bed can give you nightmares might actually be true. But it’s not just cheese; other foods, and when you eat them, can make a difference to sleep and dream quality.
There’s a long-standing belief, rooted in literature and culture, that eating cheese before bed will give you unsettling dreams. For example, the American newspaper comic strip Dream of the Rarebit Fiend, which began in 1904, had a recurring theme: a character experienced a nightmare or bizarre dream, often after consuming Welsh rarebit, a rich cheese sauce served on toast.
However, despite the folklore, there has been very little research into whether consuming cheese – and other kinds of foods – before bed actually affects sleep and dreams. A new study led by the Université de Montréal in Canada may hold the answer.
“Nightmare severity is robustly associated with lactose intolerance and other food allergies,” said lead author Tore Nielsen, PhD, from the Department of Psychiatry and Addiction at the University. “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 or bad dreams!”
The researchers focused on whether certain foods, such as cheese or sweets, food sensitivities like lactose intolerance, and eating habits, like eating late at night, could affect sleep quality and dream characteristics. They recruited 1,082 undergraduate students with an average age of 20 from MacEwan University in Alberta, Canada. Participants completed a detailed online survey covering their diet, sleep quality, dream recall, food sensitivities, and general health.
Many participants (40.2%) reported that eating affected their sleep in some way. A total of 24.7% said that eating particular foods made their sleep worse, while 20.1% said that foods made it better. The foods blamed for worse sleep included desserts or sweets, spicy foods, and dairy products. Foods credited for better sleep included fruits, vegetables, and herbal tea.
Only 5.5% believed that food affected their dreams. Of those who did, desserts or sweets and dairy products were most often linked to bizarre, vivid, or disturbing dreams. Participants with lactose intolerance or food allergies reported having more nightmares. Lactose intolerance was significantly linked to nightmares, but this connection was explained mostly by gastrointestinal (GI) symptoms such as bloating or cramps. Food allergies also predicted nightmare frequency, independent of GI symptoms.
“Nightmares are worse for lactose intolerant people who suffer severe gastrointestinal symptoms and whose sleep is disrupted,” Nielson said. “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.”
Regarding eating habits, late-night eating – eating in the evening or during the night – was associated with poor sleep quality, more negative dreams, and more frequent nightmares. Healthier eating, including consuming foods that align with the body's needs and avoiding late-night meals, predicted better dream recall and more positive dream content.
The study has some limitations. It was a correlational study, so it can’t prove causation; it can only show an association between variables. It’s unclear whether diet affects dreams, dreams affect diet, or if another factor affects both. The participants were mostly young Canadian university students, so the results may not generalize to other age groups or populations. Self-reporting based on participants’ perceptions and memories can be unreliable. The researchers acknowledged that they didn’t directly assess participants’ cultural beliefs or folklore about food and dreams, which might affect responses.
Nevertheless, the study’s findings could have practical implications. People who suffer from nightmares may benefit from tracking and adjusting their diet, particularly reducing dairy intake if they’re lactose intolerant. The findings may also improve eating habits by avoiding heavy, sugary, or dairy-laden foods before bed and eating more whole foods, which may help with both sleep quality and dream tone. The study supports growing evidence that gut health can affect mental and emotional states. And, adjusting diet may be a low-risk, non-drug way of improving sleep and reducing nightmares.
“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 large population,” said Nielson. “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.”
The study was published in the journal Frontiers in Psychology.
Source: Université de Montréal
