A recent investigation involving 1,082 students at MacEwan University has uncovered a notable correlation between experiencing nightmares and lactose intolerance. Participants were surveyed regarding their sleep patterns, dietary practices, and any perceived connections between these factors. The research suggests that nocturnal gastrointestinal discomfort, potentially stemming from lactose intolerance, may adversely influence dream content.
Nielsen et al. propose a potential link between lactose intolerance, dairy consumption, distressing dreams, and diminished sleep quality. Image courtesy of Micha HNBS.
“The intensity of nightmares demonstrates a strong association with lactose intolerance and other food-related sensitivities,” stated Dr. Tore Nielsen, an academic affiliated with the Université de Montréal.
“These emergent insights suggest that modifications to dietary regimens for individuals with certain food sensitivities could lead to a reduction in nightmare occurrences.”
“Furthermore, these findings might elucidate the prevalent tendency for individuals to attribute unsettling dreams to dairy product consumption!”
As part of the investigative process, the 1,082 students from MacEwan University were queried about their sleep duration and quality, the nature of their dreams including nightmares, and any perceived relationships between various dream types and specific food items.
Inquiries were also made concerning the participants’ psychological and physiological well-being, as well as their attitudes toward food.
Approximately one-third of the surveyed individuals reported experiencing frequent nightmares. Female participants reported a higher incidence of dream recall, as well as poorer sleep and nightmares, and were nearly twice as likely as their male counterparts to disclose a food intolerance or allergy.
Around 40% of those involved indicated a belief that late-night eating or particular foods had an impact on their sleep quality; approximately 25% held the opinion that certain comestibles could exacerbate sleep disturbances.
Individuals who adhered to less salutary dietary patterns were more prone to experiencing adverse dreams and evinced a decreased propensity for dream recollection.
“We are frequently approached with questions regarding the influence of food on dreaming – particularly by media representatives during food-centric festivities. We now possess some empirical evidence,” Dr. Nielsen commented.
The majority of participants who attributed their sleep disturbances to food cited sweets, piquant dishes, or dairy products as the culprits.
A relatively modest segment of respondents — merely 5.5% — felt that their dietary intake affected the emotional tenor of their dreams. However, a significant proportion of these individuals stated that they believed confectioneries or dairy products contributed to more disturbing or peculiar dream experiences.
Upon juxtaposing reports of food intolerances with accounts of distressing dreams and suboptimal sleep, the researchers identified a connection between lactose intolerance and symptomatic gastrointestinal distress, nightmares, and diminished sleep quality.
It is plausible that the ingestion of dairy products triggers gastrointestinal upset, and the resultant discomfort subsequently influences individuals’ dreams and the restorative nature of their sleep.
“Nightmares are more severe for individuals with lactose intolerance who experience significant gastrointestinal discomfort and whose sleep is compromised,” Dr. Nielsen elaborated.
“This observation is logical, given our understanding that other physiological sensations can indeed shape dream experiences.”
“Nightmares can be profoundly disruptive, particularly when they recur frequently, as they tend to rouse individuals from sleep in a state of emotional distress.”
“These episodes may also foster avoidance behaviors related to sleeping.”
“Both of these consequences can deprive individuals of truly restful sleep.”
The results of this investigation have been published in the scientific journal Frontiers in Psychology.
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Tore Nielsen et al. 2025. More dreams of the rarebit fiend: food sensitivity and dietary correlates of sleep and dreaming. Front. Psychol 16; doi: 10.3389/fpsyg.2025.1544475
