This is a story about a woman, a bowl of chili, and a very strange evening. The woman is me; the chili was purchased from a takeout place a few weeks ago; the strangeness of the evening — well, that was all in my head, and it all went down when I fell asleep with a full belly somewhere around ten o’clock.
Most of my dreams, I should say, tend to be pretty boring. That night, though — I don’t quite remember the details, but I do remember that things got a little upsetting, and a lot weird. And then I woke up and vowed never to eat chili again.
Here’s the problem, though: It was kind of delicious, and a lifetime ban feels a bit drastic. True, most people have heard that certain foods can cause strange dreams (spicy things and cheese, both of which were in this dish, being two of the most common culprits). On the other hand, we’re wired to search for meaning in randomness, meaning we often spot patterns where none actually exist. I ate some chili and then I had a vivid nightmare later that night; is there really a chance that the two are related?
The short answer is that there really isn’t an answer, says neuroscientist Gary Wenk, a professor at the Ohio State University and the author of Your Brain on Food: How Chemicals Control Your Thoughts and Feelings. Or at least, there’s not a firm one — the science on diet and dreams is rather sparse, which is strange, considering that both elements are universal experiences. “Why on Earth don’t we have reams and reams of data? Everybody eats, everybody dreams, and yet we don’t seem to have any evidence out there beyond anecdotes and myths,” he says. “No one’s reporting this systematically. There’s probably a lot of data out there — it just doesn’t exist in any organized fashion.”
One exception: In a 2015 study in the journal Frontiers in Psychology, researchers surveyed 382 college students about whether they’d ever noticed certain foods or late-night snacking leading to bizarre dreams. Just under 18 percent said they had, with the majority pointing to dairy and spiciness as the causes (interestingly, the subjects were more likely to blame spicy foods for upsetting dreams, and sugary foods for purely strange ones).
As the study authors noted, though, these results don’t necessarily show that these food groups really did cause the dreams in question — only that the dreamers believed they did. The researchers offered up a possibility they termed the “folklore hypothesis”: the idea that “an individual’s tendency to perceive particular foods as affecting their dreams originates in the assimilation of beliefs about food that have been transmitted intergenerationally within families, groups, or the broader culture.” In other words, we humans are a highly suggestible bunch, and the diet-dreaming link isn’t immune to the power of the placebo effect. In fact, it may be a product of it.
But the study authors also brought up another possibility: that bad dreams are more in your gut than in your mind, and that these foods were indirectly influencing participants’ dreams by interacting with their bodies. Past research has shown that sleep disruption is a common symptom of gastrointestinal distress — and “if your sleep cycle’s distorted, you’re probably not going to dream normally,” Wenk says. If your stomach’s acting up, then, drifting in and out of sleep as you deal with the discomfort may lead to some out-of-the-ordinary dream scenarios. And because we only remember dreams when we awaken from them directly, waking up multiple times during the night means more of them will stick in your brain.
That’s not to say that foods that are easier on the stomach are totally blameless. Technically, any food can play a role in dreaming — it’s not necessarily what you’re eating, but the act of eating itself. Your internal temperature rises as your body metabolizes food; a higher temperature, in turn, leads to increased activity during REM sleep, the stage of the sleep cycle where most dreaming takes place (this is also why so many people experience vivid fever dreams). If you chow down shortly before bed, you may still be digesting by the time you hit REM.
And, yes, it’s also possible that the food itself could be messing with your mind. When talking about eating in relation to dreaming, Wenk explains, it’s helpful to think of food like drugs: Both, after all, are just groups of molecules that you’re putting in your body. And while most substances can’t cross the blood-brain barrier, there are a few that can — including compounds found in some spices, which can have psychoactive properties when consumed in large quantities. Nutmeg, for example, is chemically similar to ecstasy. You’re probably not consuming mass quantities of nutmeg in a single sitting — or at least, not enough to get you high — but eating a dish that’s heavily seasoned with lots of different spices may be enough to trigger some strange activity in your subconscious. (Side note: Please don’t try to get high off of nutmeg, unless you’re ready for some deeply unpleasant side effects.)
So how do you know when your dinner is to blame for your night full of nightmares? Unfortunately, only by trial and error — everyone is affected differently by different foods, and to different degrees. “We know that some people are hyperresponders to drugs,” Wenk says. “My guess is the same thing is true for food and dreams.” If my next chili night goes horribly awry, in other words, at least I can say it was all in the name of science. Because I’m weak, and there will almost certainly be another one.