Will eating cheese before bed really trigger nightmares? Here's what the science says

Daily Maverick

5 days ago

Can what you eat before sleep really shape your dreams? New research investigates whether dairy products might influence your night's rest and dream recall.
Have you heard people say that eating cheese before bed will cause you to have vivid dreams or nightmares? It's a relatively common idea. And last week, a new study landed this suggestion back in the spotlight.
But is it true? Let's unpack the evidence.
A gouda night's sleep?
Canadian researchers recently investigated this idea in a sample of 1,082 undergraduate psychology students. The students completed a survey, which included questions about how they perceived their diet to influence their sleep and dreams.
About 40% of participants reported that certain foods affected their sleep, with 25% of the whole sample claiming certain foods worsened their sleep and 20% reporting certain foods improved their sleep.
Only 5.5% of respondents believed what they ate affected the nature of their dreams. But many of these people thought sweets or dairy products (such as cheese) made their dreams more strange or disturbing and worsened their sleep.
In contrast, the participants reported that fruits, vegetables and herbal teas led to better sleep.
This study used self-reporting, meaning the results rely on the participants recalling and reporting information about their sleep and dreams accurately. This could have affected the results.
It's also possible that participants were already familiar with the notion that cheese causes nightmares, especially given they were psychology students, many of whom may have studied sleep and dreaming.
This awareness could have made them more likely to notice or perceive that their sleep was disrupted after eating dairy. In other words, the idea that cheese leads to nightmares may have acted like a self-fulfilling prophecy and the results may have overestimated the actual likelihood of strange dreams.
Nevertheless, these findings show that some people perceive a connection between what they eat and how they dream.
Although there's no evidence to prove that cheese causes nightmares, there is evidence that does explain a link.
The science behind cheese and nightmares
Humans are diurnal creatures, meaning our body is primed to be asleep at night and awake during the day. Eating cheese before bed means we're challenging the body with food at a time when it really doesn't want to be eating.
At night, our physiological systems are not primed to digest food. For example, it takes longer for food to move through our digestive tract at night compared with during the day.
If we eat close to going to sleep, our body has to process and digest the food while we're sleeping. This is a bit like running through mud – we can do it, but it's slow and inefficient.
Cheese can be particularly challenging to digest at night because of its high concentrations of fat and protein, which slow down our digestion.
If your body is processing and digesting food instead of focusing all its resources on sleep, then this can affect your shut-eye. Research has shown that eating close to bedtime reduces our sleep quality, particularly our time spent in rapid eye movement (REM) sleep, which is the stage of sleep associated with vivid dreams.
People will have an even harder time digesting cheese at night if they're lactose intolerant, which might mean they experience even greater impacts on their sleep. This follows what the Canadian researchers found in their study, with lactose intolerant participants reporting poorer sleep quality and more nightmares.
It's important to note that we might actually have vivid dreams or nightmares every night – what could change is whether we're aware of the dreams and can remember them when we wake up.
Poor sleep quality often means we wake up more during the night. If we wake up during REM sleep, research shows that we're more likely to report vivid dreams or nightmares that we might not even remember if we hadn't woken up during them.
This is very relevant for the cheese and nightmares question. Put simply, eating before bed impacts our sleep quality, so we're more likely to wake up during our nightmares and remember them.
Can I still have Brie before bedtime?
Don't panic – I'm not here to tell you to give up your cheesy evenings. But what we eat before bed can make a real difference to how well we sleep, so timing matters.
General sleep hygiene guidelines suggest avoiding meals at least two hours before bed. So even if you're eating a very cheese-heavy meal, you have a window of time before bed to digest the meal and drift off to a nice peaceful sleep.
Cheese isn't the only dairy product that may influence our sleep. Most of us have heard about the benefits of having a warm glass of milk before bed.
Milk can be easier to digest than cheese. In fact, milk is a good choice in the evening because it contains tryptophan, an amino acid that helps promote sleep.
Nevertheless, we still don't want to be challenging our body with too much dairy before bed. Participants in the Canadian study did report nightmares after eating dairy, and drinking milk close to bedtime might have contributed to this.
Although it's wise to steer clear of food (especially cheese) in the two hours before lights out, there's no need to avoid cheese altogether. Enjoy that cheesy pasta or cheese board – just give your body time to digest before heading off to sleep. If you're having a late-night cheese craving, opt for something small. Your sleep (and your dreams) will thank you. DM
First published by The Conversation.
Charlotte Gupta is a senior postdoctoral research fellow at Central Queensland University and a member of the Appleton Institute and HealthWise research group.
This story first appeared in our weekly Daily Maverick 168 newspaper, which is available countrywide for R35.