co-written by Rick Olazabal, BSc, BN
This is a very interesting and intriguing question.
We know that certain foods can affect our mood, alertness, quality of sleep (e.g. caffeine or sugar), and that the nutritional value of food directly impacts our health (e.g. macronutrients, vitamins and minerals)…
So why wouldn’t food affect our dreams?
To answer this question, first we must ask ourselves another question, what are dreams? Freud believed that dreams are a window into the unconscious, but strictly speaking, dreams are images, thoughts, sounds, and subjective sensations experienced when we sleep. This can include people you know, people you’ve never met, places you’ve been, and places you’ve never even heard of—but it can also include food you’ve eaten.
Is it a myth or truth that food can cause bad dreams?
As it stands, there is no good quality study that provides evidence to support a link between the foods that we eat and the dreams we have. A “Psychology Today” online article discussed one Canadian study of nearly 400 university students where less than 20% of the participants reported a connection between the food they ate and any influence on their dreams.
The authors of the study concluded, among other possibilities, that “food influences dreams indirectly due to poor metabolism or digestive intolerances. For instance, eating too late at night could negatively affect metabolism and sleep quality, thence seeping into your dreams.” What this study did find was evidence that people “believe” there is a direct connection between the foods they eat and the dreams they have.
Does it depend of the type of food or the time just before we go to bed?
Among small number of people who believed food could influence their dreams, this study found that certain foods were more likely to be reported as the reason for bad dreams. For example, dairy (including cheese and ice cream) were more linked to “disturbing” or “bizarre” dreams; spicy foods were second most likely to cause discomforting dreams; and sweet foods were linked with “bizarre” rather than “disturbing” dreams. Further, another small number of subjects reported that eating late eating late was most commonly associated with nightmares.
What type of foods can affect our dreams?
Certain foods can affect sleep, and sleep quality. For example, foods high in certain amino acids (tryptophan or 5-HTP), some B vitamins, and so on, are directly related in the production of the sleep hormone, melatonin. Because of this, a diet high in these products may help support sleep. However, that is not to say that if you eat a lot of turkey you will fall asleep–other factors play a role too. If you are able to get sound, deep sleep, you’re most likely to hit REM or restorative sleep; during this phase of the sleep cycle there’s a lot of brain activity going on.
People who finally “catch up” on their sleep are more likely to have vivid dreams simply because they’re—again—finally sleeping enough. So we really need to wonder, is it the food itself that affects our dreams, or is it that there’s a confounding factors (that is, a coincidence) between the food we eat and our health/mental state at the time of eating it (e.g. lower stress, more happy)?
Digestion plays a role in our sleep
Of course, if you ate something that did not agree with you, heartburn or nausea can wake you up—or at least enough to bring you in and out of sleep or consciousness. This can be perceived as bad dreaming. Different foods have different rates of digestion and absorption. If you have issues with stomach acidity (too little or too much); nutritional deficiencies that impair digestive enzymatic function (e.g. low zinc); or a food sensitivity, etc. your sleep can be affected. This is because (as we discussed in another article), there is a strong relationship between your gut (including your live, which filters and detoxifies foods and drugs) and your brain.
What can be done?
Keep a diet diary! Keep track of your diet, your sleep, your stress, your cycle (if you’re a woman) and you may be surprised by what you find! For example, I cannot tolerate certain wines and anytime I have those wines I cannot sleep due to nasal congestion, which prevents me from getting enough oxygen—my sleep is horrible! I learned this after keeping track with a diet diary. If you notice a link between your sleep quality and the foods you eat, try to avoid those foods.
Now, if indigestion keeps you up (or wakes you up), you may want to experiment with a spoonful of apple cider vinegar or fermented products containing lactic acid (enhances viability of good gut bacteria, and improved enzymatic function) before every major meal (for up to a week).
You may also want to ask a naturopathic doctor about milk thistle, boldo, and other herbs associated with improving hepatic (liver) processing of foods—this may be practical, especially if you notice headaches or migraines when you eat certain foods.
Finally, it may not be a bad idea to ask about B vitamins and zinc supplementation. B vitamins help in the processing of carbohydrates, and zinc is required in a multitude of digestive functions.