A new study suggests that eating too much dairy—especially if you’re lactose intolerant—might be disturbing your sleep and giving you nightmares. Researchers surveyed more than 1,000 university students and discovered a strong link between nightmares and food sensitivities, particularly reactions to dairy.
The study, led by Dr. Tore Nielsen from the Université de Montréal and published in Frontiers in Psychology, found that people who experience discomfort from dairy, such as gas or stomach pain, may also have more disturbing dreams and poorer sleep. This discomfort during the night could be triggering bad dreams and even waking people up in an anxious state.
The idea that food affects dreams is not new. For generations, people have believed that eating certain foods—like cheese before bed—could lead to strange or scary dreams. But scientific proof has been lacking.
To find some answers, the research team asked students at MacEwan University about their eating habits, sleep quality, and dreams. They also asked about their physical and mental health and how they personally felt food influenced their sleep or dreams.
About one-third of the students said they regularly had nightmares. Women were more likely than men to remember their dreams and report having sleep problems or nightmares. They were also nearly twice as likely to report a food intolerance or allergy.
Interestingly, around 40% of the students believed that eating late at night or certain foods affected their sleep, while a quarter believed that some foods made their sleep worse.
People with poor diets were more likely to have bad dreams and less likely to remember any dreams at all. When asked what types of food they thought made dreams worse, the most common answers were sweets, spicy food, and dairy.
A small group—just over 5%—specifically said that what they ate affected the tone of their dreams. Among those, many blamed dairy or sugary foods for making their dreams more disturbing or strange.
When researchers looked more closely at students with food intolerances, they found that those with lactose intolerance had more stomach issues during the night. These symptoms were strongly linked to nightmares and poor sleep quality.
Dr. Nielsen explained that this connection makes sense because we already know that physical discomfort—like pain or illness—can influence what we dream about.
Nightmares are not just unpleasant—they can seriously disturb sleep. They often wake people up suddenly and can make them anxious or fearful of going back to sleep. Over time, frequent nightmares can lead to long-term sleep problems and avoidance behaviors, like staying up late to avoid falling asleep.
Interestingly, fewer people in this study reported a food-dream link compared to an earlier study by the same team over a decade ago. This might be because people today are more aware of food intolerances and are avoiding foods that cause them trouble—like dairy products for those who are lactose intolerant.
This raises an important point: if people know which foods upset their stomachs or make their sleep worse, simple changes in diet could help them sleep better and avoid nightmares.
However, the researchers caution that the relationship between food and dreams is still not fully understood. It’s possible that poor diet leads to poor sleep—or that poor sleep leads to worse eating habits. Or maybe another hidden factor affects both.
The researchers say that more studies are needed. They hope to test whether eating dairy products like cheese before bed actually changes people’s dreams. They also want to study people from different age groups and backgrounds to see if the findings apply more widely.
For now, if you’re prone to nightmares and you’re lactose intolerant—or sensitive to certain foods—it might be worth changing what you eat at night. A lighter, healthier evening meal could be the key to better sleep and sweeter dreams.
If you care about nutrition, please read studies about the best time to take vitamins to prevent heart disease, and vitamin D supplements strongly reduce cancer death.
For more information about nutrition, please see recent studies about plant nutrient that could help reduce high blood pressure, and these antioxidants could help reduce dementia risk.
The research findings can be found in Frontiers in Psychology.
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