As someone who almost never remembers the last night’s dreams, I have always been interested in what influences the kinds of dreams we have and how we recall them. One popular belief, which my parents swear by, is that spicy food induces strange, if not frightening, dreams. I’d taken it as common knowledge until I mentioned it to Ingrid and Hokuma while preparing a Mid-Week Delicacy involving peppers, jalapeños, and hot sauce (come back Wednesday for the recipe!) – they were surprised, having never heard of such a thing. I became curious about the legitimacy of the claim, so, as per usual, I took to Google for a bit of research.
Given that spicy food can have some pretty extreme impact on the digestive system, it seems logical to me that it could also have intense effects on the brain. After all, spicy food includes a wide array of side effects, such as making you hot, teary-eyed, and thirsty. Why wouldn’t there be some subconscious mental effects as well?
Well, in 1992, the University of Tasmania tested how having Tabasco and/or mustard as part of dinner affected the sleeping patterns of healthy young men. The participants didn’t achieve deep sleep for as long as the control counterparts did, which the study implies is likely due to the changes in body temperature caused by capsaicin. Capsaicin, a compound found in most peppers, stimulates a nerve cell protein that typically only gets triggered by physical heat – hence, describing something spicy as being ‘hot.’ Since the compound raises your internal temperature, it becomes more difficult for your body to cool itself to a lower, sleeping temperature, so your brain is more active as it performs thermoregulation. As your body has more difficulty achieving REM sleep, the sleep stage in which dreams occur, your brain experiences REM pressure, which Dr. Gary Wenk of Ohio State University describes as “an onslaught of powerful dreaming that we denied ourselves earlier in the evening.” It’s the same reason that so-called fever dreams are known to be bizarre and sometimes scary.
However, a lot of other research has shown that dream patterns are less likely to be affected by what you eat than by when you eat. In other words, a late-night meal or snack will likely cause you to dream more intensely if you go to bed soon thereafter. This is because any food, no matter how mild, will stimulate the brain as it raises your body’s metabolism and temperature, prompting more mental activity. The larger, fattier, greasier, and/or spicier your last meal is, the more effort your body has to exert to break it down and lower your temperature, and the more likely you are to have wacky dreams or nightmares. To try to prevent these, just allow at least two hours to pass between dinnertime (or late-night-snack-time) and bedtime. Fiery food doesn’t seem to have as much of an effect as some people think, but, for good measure, you can wait an extra hour before going to bed and drink some cold milk if you had a lot of peppers or hot sauce.
Another key thing is not to worry that you might have a bad dream after a big or spicy meal – the anxiety might be what ends up negatively influencing your sleeping brain! Just enjoy what you eat.