Sweet dreams are made of this,
Who am I to disagree?”
— The Eurythmics
Ever since people have been eating and dreaming, there has been a perceived connection between what we eat and what we dream. No less than Hippocrates himself is purported to have perceived that link between eating and dreaming. In Regimen 4.93 dating to approximately 400 BC, it is observed that:
“However, many strange bodies that appear in dreams and frighten a person signal an excess of uncustomary food, a secretion, bile, and a dangerous sickness. An emetic is required followed by the increase over five days of extremely light food–not too much of it or too sharp, nor too dry or hot, along with the kinds of exercises that are natural except for walking after dinner. This really asks for warm baths and relaxation, and you need to guard against the sun and the cold.
Whenever someone imagines they are eating or drinking customary food or drink while sleeping, it means a lack of food and depression in the soul. Really strong meats are a sign of excess; when they are weaker, there’s less. Just as eating is good, so too is dreaming about it! So, in the case of excess, it is helpful to reduce the quantity of food, since excessive consumption is indicated. The dreaming of bread made with cheese and honey means the same thing. There’s no sign of harm in dreaming of water. But drinking other things is a bad sign.”
But what does modern science have to say on the subject of whether what we eat can inform what we dream?
The answer is very little, but a recent study cracks the door of insight a little wider.
- The study consisted of a survey of over 1,000 (1,082) undergraduate college students at MacEwan University in Alberta, Canada, comprising 67% females and 33% males, with a mean age of approximately 20 years.
- Within the study group, 13.8% reported a medical condition and 17.1% a psychiatric condition, and approximately 32% self-reported some type of food sensitivity as well as a clinically significant frequency of nightmares (more than one per week).
- The study examined three potential hypotheses:
- food-specific; whether specific foods influence dreams directly
- food distress; whether food affects dreams through physiological symptoms
- sleep effects; whether food alters sleep quality, thus affecting dreaming.
- Women recalled more dreams than men and had more nightmares (37% versus 21%).
- Approximately 40% of respondents reported that certain foods affected their sleep (either improving or worsening sleep), and almost 6% reported that food affected their dreams.
- The group that reported food affecting their dreams had a higher rate of nightmares, which were associated primarily with the consumption of desserts and sweets (31%) and dairy (22%).
- More pleasant dreams were associated with the consumption of fruits and vegetables as well as herbal tea.
- Participants who were lactose intolerant had a higher rate of nightmares, which appeared to be related to gastrointestinal distress, providing support for the food distress hypothesis.
- Nightmares were also more common among people who ate late at night.
The Caveat:
This study sought to investigate the age-old belief of a connection between food and dreams, or, in the case of some, nightmares. Although the study does not provide definitive causal proof, it offers interesting opportunities for further investigation and intervention. There is evidence supporting a causal relationship between the food we choose to eat and the quality of our sleep. Quality sleep is essential for good health. This study supports those findings, e.g., people suffering from lactose intolerance may experience GI symptoms that affect the quality of their sleep and increase the likelihood of nightmares.
Although no causality can be demonstrated, this study did correlate poor sleep and a negative dream experience with unhealthy eating patterns, late-night eating, and the presence of gastrointestinal distress. The reason that no causality can be inferred is that it is unclear if having impaired sleep leads to worse diets, poor dietary habits result in impaired sleep, or both result from some as yet unknown variable. Late-night eating was independently associated with an increased propensity to suffer nightmares. Improved dream recall (the ability to remember what you dreamt) and better sleep were correlated with a healthier eating pattern, particularly the consumption of fruits, vegetables, and herbal teas. However, causality cannot be established for the aforementioned reasons.
Over 40% of the participants perceived that eating certain foods affected their sleep. This is particularly important because our perception of things can influence subsequent actions and outcomes. PTSD sufferers, who frequently experience nightmares, experienced fewer symptoms with a higher adherence to a Mediterranean-style diet. A Mediterranean-style diet has been shown to induce qualitative changes in the bacterial species of the gut microbiome. The gut microbiota, as discussed many times in this column, is increasingly implicated in many central nervous system processes, not the least of which can impact mental health.
Studies like this encourage further exploration of how positively impacting our food experience, including not only what we eat, but also the where, when, why, and how we eat, can improve other seemingly unrelated areas, such as sleep and mental health.
Finally, in an unsurprising twist, this one thing does confirm is that your mother was right: gobbling those late-night sweeties will give you nightmares.
The Study:
Additional Resources:
