The surprising foods fueling your insomnia and strange dreams
Drinking a warm glass of milk to help wind down before bedtime may actually be keeping you awake, according to experts.
Scientists have discovered a surprising link between poor sleep and eating late-night snacks, particularly dairy products and desserts.
In a recent study, researchers surveyed participants about their sleep quality, eating habits, and any perceived link between the two.
Participants completed questionnaires, including the Pittsburgh Sleep Quality Index and Nightmare Disorder Index, to assess their sleep and dream experiences.
Results showed that healthier evening eating habits led to better sleep and dream recall, while dairy, desserts, spicy foods, and meat consumed before bed were linked to nightmares and insomnia.
The study also found a strong link between lactose intolerance and nightmares, with scientists suggesting that gastrointestinal issues or stomach pain at night may impact sleep quality.
Ultimately, experts say it is unclear how the exact relationship between sleep and diet works, but found a strong link between lactose intolerance and poor sleep in particular.
There is previous evidence that gastrointestinal distress and nighttime GI symptoms can disrupt sleep – a 2019 study published in PubMed studied 2,752 participants and found sleep disturbance was associated with GI conditions, including gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS).
More broadly, research on nighttime reflux shows that when you’re asleep, the mechanisms that normally clear acid from the esophagus work less effectively and therefore nighttime reflux can cause sleep disruption.
Healthier evening habits lead to better sleep and recall of dreams, while the consumption of dairy, desserts, spicy foods, and meat products, have been linked to nightmares and insomnia
In the recent study, published in Frontiers in Psychology, researchers asked 1,082 students – with an average age of 20 – to complete the Pittsburgh Sleep Quality Index, a 19-item self-report questionnaire that measures sleep quality and disturbances over a one-month period, as well as the Nightmare Disorder Index, a brief five-item questionnaire designed to screen for nightmare disorders.
Participants were also asked about their diet, food intolerances, allergies, and the self-perceived effects of specific foods on their dreams.
More than 40 percent of participants said eating a late-night snack or specific food affected their sleep, for better or worse.
Twenty percent of participants said their sleep was improved by certain foods, such as fruit, herbal tea, and vegetables, compared to 24.7 percent who said certain snacks such as desserts, dairy, and spicy foods, worsened it.
When researchers looked specifically at disturbing dreams after nighttime eating, they found that most participants had eaten dairy or desserts before bed.
Participants with lactose intolerance were significantly more likely to report that any late night snack worsened their sleep.
Among those who said food negatively affected their sleep, 29.6 percent were lactose intolerant, compared with 19.5 percent of those who said food did not disrupt their sleep, according to the study.
Researchers believe gastrointestinal discomfort from foods eaten before bed may be the culprit for disrupted sleep, triggering vivid or disturbing dreams.
‘Nightmares are worse for lactose intolerant people who suffer severe gastrointestinal symptoms and whose sleep is disrupted,’ Dr Tore Nielsen of Université de Montréal, lead author of the study, told Frontiers.
‘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,’ Nielsen said.
Experts found a strong association between nightmares and poor sleep and lactose intolerance
‘They might also produce sleep avoidance behaviors. Both symptoms can rob you of restful sleep.’
Researchers also found that late-night snacking in general, regardless of the food, was linked to more negative dreams and nightmares.
Meanwhile, participants who rarely snacked late at night were more likely to recall their dreams than those who regularly ate before bed.
Dream recall is partly influenced by how often you wake up during the night and how you transition out of deep sleep.
‘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 for bad dreams!’
The author noted several limitations, including that the study relied on self-reported survey data and did not use a random sample of the general population.
‘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 larger population,’ Nielsen said, adding they would like to run an additional study where participants ingest dairy products versus a control food.
