Ilaria Rosella Pagliaro New research confirms cheese before bed causes nightmares. Study of 1,082 students shows lactose intolerance linked to disturbing dreams through gut-brain connection.
For years, we’ve been told that eating cheese before bedtime could lead to bizarre dreams or nightmares. What might have seemed like nothing more than an urban legend or folk wisdom—immortalized in Winsor McCay’s famous 1904 comic strip “Dream of the Rarebit Fiend”—now has scientific backing. A groundbreaking study published in Frontiers in Psychology and conducted by a team at the University of Montreal, led by Dr. Tore Nielsen, has discovered a concrete link between certain food intolerances, particularly lactose intolerance, and an increase in disturbing dreams.
The findings reveal that cheese, along with sweets and spicy foods, when consumed before bedtime, can indeed influence sleep quality and dream content. And the culprit? It appears to be our gut, in constant communication with our brain through what scientists call the gut-brain axis.
How evening snacks transform into midnight terrors
To conduct this research, the team collected and analyzed data from 1,082 university students, investigating their eating habits, food sensitivities, sleep quality, and dream content. The results paint a clear picture: about one-third of respondents reported suffering from frequent nightmares, while 40 percent noticed a correlation between food and sleep. More specifically, 5.5 percent identified specific foods as the cause of their disturbing dreams.
Among the foods under suspicion, cheese wasn’t actually the primary culprit. Sweets topped the list, followed by dairy products and spicy dishes. However, researchers observed that people with lactose intolerance tend to experience more negative dreams and recurring nightmares. The reason? Gastrointestinal disturbances—bloating, gas, cramps—appear to influence sleep quality, disrupting rest and transmitting unpleasant sensations to the brain, which then processes them during REM sleep.
As Dr. Nielsen, who directs the Dream & Nightmare Laboratory at Montreal’s Sacred Heart Hospital, explains: “Nightmare severity is robustly associated with lactose intolerance and other food allergies. These new findings imply that changing eating habits for people with some food sensitivities could alleviate nightmares.”
More sophisticated statistical analysis confirmed that it’s not cheese per se that causes negative dreams, but rather the physical consequences it produces in those who can’t digest it properly. In other words, if you’re lactose intolerant and grab a cheese snack before sleep, you might wake up in the middle of the night after a nightmare. The issue isn’t the food itself, but how your body reacts to it.
Beyond dairy: the wider picture
The research also revealed other fascinating aspects. Sweets like cakes and cookies were more frequently associated with strange dreams or nightmares compared to cheese. Spicy foods were also often mentioned among the causes of disturbing dreams.
But it’s not just about what we eat—timing matters too. Eating late in the evening, especially without genuine hunger, was associated with a higher incidence of negative dreams. Conversely, those who habitually dine early and light tend to recall their dreams with greater clarity, and these are often less emotionally charged.
Another curious finding concerns mindful eating: people who listen to hunger signals, avoid emotional eating, and consume more fruits, vegetables, and herbal teas reported more peaceful sleep and calmer dreams. In contrast, those with chaotic eating patterns, featuring heavy evening meals and few plant-based foods, reported disturbed sleep and frequent nightmares.
Of course, the study authors caution against hasty conclusions: correlation doesn’t necessarily mean causation. It’s not yet clear whether food influences dreams or whether other factors, like stress or emotions, affect both diet and sleep simultaneously.
The Gut-Brain connection Is real
In recent years, science has confirmed that the gut and brain communicate constantly through what’s known as the gut-brain axis. This connection explains why gastrointestinal disorders (like irritable bowel syndrome, or IBS) can also influence mood, sleep cycles, and even dreams.
Some studies have observed that an anti-inflammatory diet, such as the Mediterranean diet, can help reduce the frequency and intensity of nightmares, especially in subjects suffering from PTSD (post-traumatic stress disorder). According to Nielsen, this could open new pathways in preventing sleep disorders through nutrition.
The researcher emphasizes that for years, journalists have asked him whether there’s truly a link between food and dreams. “Now we have some answers,” he says. The next step will be conducting controlled studies analyzing how dream content changes after eating, for example, cheese versus neutral foods. Only then will we have a definitive answer.
The science behind sweet dreams
The mechanism appears surprisingly straightforward once you understand it. When lactose-intolerant individuals consume dairy products, their bodies struggle to break down the lactose sugar. This leads to fermentation in the gut, producing gas, bloating, and discomfort. These physical sensations don’t just disappear when we fall asleep—they continue to send signals to our brain throughout the night.
“Nightmares are worse for lactose intolerant people who suffer severe gastrointestinal symptoms and whose sleep is disrupted,” Nielsen told researchers. “This makes sense, because we know that other bodily sensations can affect dreaming.”
The timing couldn’t be more critical. When we experience gastrointestinal distress during REM sleep—the phase when our most vivid dreams occur—our brain incorporates these uncomfortable physical sensations into our dream narratives. What might have been a peaceful dream about flying suddenly becomes a nightmare about falling, or a gentle conversation turns into an argument filled with anxiety.
What this means for your bedtime routine
The implications extend far beyond just avoiding cheese before bed. The research suggests that people who practice conscious eating habits—paying attention to genuine hunger cues, choosing whole foods over processed ones, and timing meals appropriately—experience not only better physical health but also more restful sleep and pleasant dreams.
For those with known lactose intolerance or other food sensitivities, the message is clear: dietary adjustments could serve as a first line of defense against recurring nightmares. Rather than reaching for sleep medications or other interventions, simply changing what and when you eat might provide significant relief.
The study also hints at broader implications for our understanding of sleep disorders. If dietary factors can influence dream content and sleep quality so dramatically, it opens up entirely new avenues for non-pharmacological treatments for various sleep disturbances.
Meanwhile, if you find yourself having nightmares after an evening snack of sweets or dairy products, you’re not alone—it might be your gut sending a message to your brain. And your dreams, it appears, are definitely listening.
Source: Frontiers in Psychology
