If you want good night's sleep, maybe you should think twice about that big glass of milk before bedtime. Or that bowl of ice cream, or the cold slice of cheese pizza.
According to new research by Canadian psychologists Tore Nielsen and Russell Powell, people's eating habits can have disruptive effects on their patterns of sleep and dreaming. Nielsen and Powell surveyed almost 400 college students (130 males, 264 females) about their diet, sleep, and dream experiences. The resulting article is titled "Dreams of the Rarebit Fiend: Food and diet as instigators of bizarre and disturbing dreams," in the journal Frontiers in Psychology 6 (2015), article 47, 1-18. The title refers to a popular and quite surrealistic comic strip from the early 1900's, Winsor McCay's Dream of the Rarebit Fiend, in which people who ate a meal of cheesy "Rarebit" sauce were plunged into strange dreams and nightmares.
Nielsen and Powell found that 18 percent of their participants, or about one in five people, responded yes, "food can render their dreams more bizarre or disturbing." The participants identified several different causes for the impact of food on their dreams:
• Eating lots of food late at night, which can cause gastro-intestinal discomfort and difficulty sleeping.
• Eating too much of specific kinds of foods, like dairy products and spicy dishes, which also cause indigestion and sleep problems.
• Emotional eating, such as when unhappiness in life prompts binge-eating behavior, which can then disrupt sleep and trigger negative dreaming.
• Fasting or dieting, which change one's bodily functioning in ways that also affect the contents and intensity of dreaming. (As Nielsen and Powell note, fasting is a classic method used in dream incubation rituals.)
The results of this study are relevant for people who treat or deal with eating disorders. Nielsen and Powell's findings suggest a potentially therapeutic link between eating habits and sleep and dream experiences. Perhaps more attention to improving the quality of people's sleep and dreaming might help them develop healthier dietary practices and a more balanced lifestyle.
This research also has relevance for the treatment of people suffering from various kinds of trauma. Nielsen and Powell point out that binge-eating is a typical symptom of post-traumatic stress disorder (PTSD), along with disturbed sleep and intense nightmares. Perhaps therapeutic efforts to improve the eating habits of PTSD victims would help diminish the disturbances in their sleep and dreaming.
Although Nielsen and Powell acknowledge the limits of their study, its importance lies in the fact they pursued this topic at all. Almost 30 years ago, anthropologist Barbara Tedlock questioned why so little scientific attention has been given to the role of food in dreaming:
"Since eating is more basic in humans than either sexuality or aggression, it is astounding to notice this neglect of the analysis of eating within Western depth psychology."
Nielsen and Powell deserve great credit for finally taking some empirical steps toward improving our knowledge in this area.
Based on their initial findings, it appears we are what we eat, in sleeping as well as waking life.
Barbara Tedlock, "Zuni and Quiche Dream Sharing and Interpreting," in Dreaming: Anthropological and Psychological Interpretations (New York: Cambridge University Press, 1987), p. 106.