- Researchers estimate that about 56% of people in the United States and 31% in Western Europe have a sleep disorder.
- Past studies have shown that about 5% of adults have frequent nightmares.
- There are a number of known causes for nightmares, including some that are food-related.
- A new study has found eating too much dairy, especially for those who are lactose intolerant, may be causing nightmares and sleep disturbances.
Past studies have shown that many people around the world have trouble getting a good night’s sleep. Researchers estimate that about 56% of people in the United States and 31% in Western Europe have a sleep disorder.
One reason why people may struggle with sleep is due to nightmares. Previous research reports that about 85% of adults have a nightmare at least once a year, with about
There are a number of possible causes for nightmares. Some are tied to mental health issues, such as post-traumatic stress disorder (PTSD), stress, and anxiety.
Certain medications and the use of illicit drugs and alcohol can also bring on nightmares. And eating before bedtime may also put a person at a higher risk of this.
“Sleep disturbances affect a huge proportion of the general population; one large survey found that 30-40% of individuals will have a clinically significant sleep disorder in their lifetime,” Tore Nielsen, PhD, professor in the Faculty of Medicine, the Department of Psychiatry and Addiction at the Université de Montréal in Canada, and director of the Dream & Nightmare Lab in the Center for Advanced Research in Sleep Medicine at the Montréal North Island Integrated University Health and Social Services Centre (CIUSSS NIM), told Medical News Today.
“We have effective treatments for some, but by no means all, of these disorders. So, any intervention that can help improve sleep contributes to the overall national battle against poor sleep,” Nielsen said.
Nielsen is the lead author of a new study published in the journal Frontiers in Psychology, which has found that eating too much dairy, especially for those who are lactose intolerant, may be causing nightmares and sleep disturbances.
For this study, researchers recruited more than 1,000 students from MacEwan University in Canada, who were asked questions regarding their sleep quality, dreams and nightmares, and their food tolerances and allergies.
“Our previous study found that dairy was the most frequently blamed food by people for affecting their dreams; this suggested lactose intolerance as an obvious explanation,” Nielsen said. “However, since we had no measures of lactose intolerance or other food sensitivities to test that possibility in that study, we decided to look deeper into the question with standardized measures of food sensitivities.”
Upon analysis, when researchers compared reports of food intolerances to reports of poor sleep and nightmares, they discovered that lactose intolerance was associated with gastrointestinal symptoms, nightmares, and low sleep quality.
“Lactose intolerance and food allergies were previously unknown to be factors that could incite nightmares,” Nielsen explained. “But with what we have now learned, we have new avenues of research and clinical intervention to develop.“
“For example, our findings suggest that avoiding allergenic foods or adjusting diets to be healthier could serve as a first line of defense against nightmares — especially in food-sensitive individuals,” he told us.
The evidence is far from conclusive but, based on the findings so far, the researcher emphasized that dietary choices could have a significant impact on night-time dreams:
“Controlling the severity of lactose intolerance could be used to lessen the severity or prevent nightmares. Other food allergies may also affect dreaming but, since we don’t yet know which ones, you should be on guard for possible connections. Reverting to a Healthy eating style may be beneficial for your dream life.”
MNT had the opportunity to speak with Inderpal Randhawa, MD, a board-certified allergist, immunologist, pediatrician, pulmonologist, and internist and founder of the Food Allergy Institute in Long Beach, CA, about this study.
Randhawa, who was not involved in this research, commented that the study was a thoughtful and creative exploration of how food sensitivities — especially lactose intolerance and general food allergies — may influence not just sleep quality but also the content and emotional tone of dreams.
“The rigor in linking gastrointestinal (GI) symptoms to nightmare severity offers novel insight into how physical discomfort from food reactions could manifest psychologically during sleep,” he said.
“Sleep quality is closely tied to both mental and physical health,“ explained Randhawa. “For individuals with food intolerances, undiagnosed or unmanaged sensitivities can lead to GI distress that disrupts sleep architecture and promotes negative dream content.”
“By exploring dietary interventions — especially personalized ones — researchers may offer low-risk, non-pharmacologic strategies to improve sleep, emotional regulation, and even mental health outcomes in populations sensitive to common food allergens,” he suggested.
“Future work should include interventional studies that test specific dietary modifications in people with known food sensitivities to determine causal effects on sleep and dream quality,” Randhawa advised. “Additionally, applying wearable sleep technology and biomarker data (e.g. cortisol, gut microbiota) could help elucidate the mechanisms linking food-induced GI distress to disrupted REM sleep or nightmare production.”
Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist and owner of Nutrition-In-Sight, not involved in this study, offered MNT her top tips on how those who may have food intolerances should eat to help improve their sleep quality.
Richard advised to:
- try to finish dinner and snacking 2 to 3 hours prior to bedtime to allow enough time for the “rest and digest” phase
- avoid spicy foods, alcohol, and caffeine too close to bedtime
- avoid fast food or foods heavy in saturated fat and added salt (i.e. pizza, burgers and fries, fried chicken)
- eat a well balanced meal of protein, fat, and carbohydrates until you are satisfied, but not feeling “stuffed”
- if you need a snack before bed, opt for something easier to digest but filling like a nut butter and fruit, trail mix, or hummus and crackers or veggies
- keep a food log or journal to observe patterns and associations between what you eat, your dreams/ nightmares, and quality of sleep
- be sure to adequately hydrate with water or caffeine-free herbal teas like lemon balm, chamomile, or lavender, avoiding carbonation or sugar-sweetened beverages.
“I recommend prioritizing meeting with a registered dietitian nutritionist (RDN) if you need specific recommendations due to a food intolerance such as lactose, gluten, food allergy, or other or if what you’re eating is affecting your sleep patterns, quality of sleep and duration,” she added, noting that “digestive enzymes, supplements, or other recommendations may be appropriate to implement.”
On a lighthearted note, Richard said that: “‘Desserts’ spelled backwards is ‘stressed’ — try not to restrict or deprive yourself of things that bring you joy, but overindulging can wreak havoc as well.”
Finally, she advised: “Work with an RDN and your healthcare team to figure out what may be driving your cravings, patterns or body’s messages. Listen to your sweet tooth, but be mindful. Here’s wishing you sweet dreams!”
