Does cheese give you nightmares?

Key takeaways

• Verdict: partly true. No controlled study has shown that cheese causes nightmares. The link that does exist runs through upset stomachs and late eating.

• The idea is old. Scrooge blamed “a crumb of cheese” for Marley’s ghost in 1843, and a 1904 comic strip built a whole series around Welsh rarebit dreams.

• The only bedtime cheese trial was a marketing study. The British Cheese Board’s 2005 study of 200 people reported no nightmares at all.

• Lactose intolerance is the likeliest culprit. In a 2025 survey of 1,082 students, people with lactose intolerance had worse nightmares, and the link went away once gut symptoms were accounted for.

• Late eating showed up too. The same survey found that more evening eating predicted more severe nightmares.

Where the cheese and nightmares idea comes from

In the first chapter of A Christmas Carol (1843), Scrooge refuses to believe in Marley’s ghost. A bad stomach can fool the senses, he argues, so the ghost might be “an undigested bit of beef, a blot of mustard, a crumb of cheese, a fragment of an underdone potato.” He follows it with a pun: “There’s more of gravy than of grave about you, whatever you are!”

About 60 years later the cartoonist Winsor McCay turned the idea into a comic strip. Dream of the Rarebit Fiend started in the New York Evening Telegram in September 1904, and the strips usually followed the same plan: someone eats Welsh rarebit (melted cheese on toast) before bed, has a strange or frightening dream, and wakes up in the last panel regretting supper. Its original run lasted until 1911, with a short revival in the 1920s.

The cheese study that found no nightmares

The “research” most often quoted on this question is a 2005 study by the British Cheese Board, an industry group. As NPR and DairyReporter reported at the time, 200 volunteers ate 20 grams of cheese (about two-thirds of an ounce) half an hour before bed for a week and kept notes on their sleep and dreams.

Nobody reported a nightmare. The Board said Stilton produced the oddest dreams, cheddar brought on dreams about celebrities, and Cheshire gave the plainest nights. It also said it hoped the results would get people eating more cheese at bedtime. There was no control group, and the results never appeared in a peer-reviewed journal.

What the research shows

The serious work comes from the dream researcher Tore Nielsen at the Université de Montréal and the psychologist Russell Powell at MacEwan University in Canada.

In a 2015 study, they asked 396 students whether food affected their dreams. About 18% said it did. Dairy was blamed more than any other food: 44% of the students who named a food behind their disturbing dreams named dairy, and it was the only food group blamed more often than chance would predict.

That study only recorded what students believed, so in 2025 the same group ran a larger survey of 1,082 students that asked about food sensitivities, eating habits, sleep and nightmares. This time only 5.5% said food affected their dreams.

Students who were lactose intolerant slept worse and scored higher for nightmare severity. Once the researchers accounted for gut symptoms such as cramps and bloating, the link with lactose intolerance disappeared, which suggests the stomach trouble was doing the work. Eating habits showed up as well: students who ate more in the evening scored higher for nightmare severity, and night eating went with poorer sleep and darker dreams.

The authors describe their results as “essentially correlational.” Both studies relied on what students reported about themselves, and neither fed anyone cheese and watched what happened.

Why a late snack could change your dreams

The long, vivid, story-like dreams happen mostly in REM sleep, and you only remember a dream if you wake during it or soon after. In the classic 1957 sleep-lab experiments by William Dement and Nathaniel Kleitman, people woken from REM sleep described a dream about 80% of the time; people woken from other stages did so about 7% of the time.

So anything that wakes you more often gives you more chances to catch a dream on the way out. Indigestion, reflux and a full bladder can all do it, and a big late dinner makes the first two more likely.

Lactose comes into it as well. Aged hard cheeses such as cheddar and Parmesan contain very little lactose, while fresh, soft cheeses and milk carry much more. For someone who’s lactose intolerant, a bowl of ice cream or a milky drink is more likely to cause trouble than a slice of aged cheddar.

Cheese also contains tryptophan, the amino acid behind the turkey-makes-you-sleepy story, but there’s no good evidence that the amount in a snack changes sleep or dreams. Tyramine, a compound in aged cheese, gets blamed too; no study has tied it to dreams.

What actually causes nightmares

Nightmare disorder, where frequent nightmares cause real distress, affects about 4% of adults, according to the American Academy of Sleep Medicine (AASM). The main causes:

• Stress and trauma, especially PTSD: up to 80% of people with PTSD report nightmares.

• Medications that act on serotonin, norepinephrine or dopamine, including some antidepressants and some blood pressure drugs. Stopping certain medications can set them off too.

• Alcohol, which suppresses REM sleep early in the night and can bring a rebound of REM later on.

• Too little sleep, which can cause a REM rebound of its own.

Frequent or upsetting nightmares are worth raising with a doctor. The AASM recommends image rehearsal therapy, in which you rewrite a recurring nightmare while awake and rehearse the new version.

Verdict: partly true

Cheese doesn’t contain anything known to cause nightmares, and the only bedtime cheese trial, run by people selling cheese, found none. Nightmares are linked to lactose intolerance through gut symptoms, and to eating late. If a cheese board at 11pm gives you a rough night, the late hour and a full stomach are the likelier causes.

What to do instead: leave a few hours between a big or rich meal and bedtime. If you’re lactose intolerant, go easy on milky foods in the evening, or stick to aged cheeses.

Frequently asked questions

Does eating cheese before bed give you weird dreams?

There’s no reliable evidence. The idea that Stilton brings on bizarre dreams traces back to a cheese industry promotion with no comparison group.

Can lactose intolerance cause nightmares?

Probably, through the stomach. In the 2025 survey of 1,082 students, those who were lactose intolerant reported worse nightmares, but the difference went away once their bloating and cramps were taken into account.

Does eating late at night cause nightmares?

Possibly. Students who ate more in the evening reported worse nightmares, and a full stomach can bring on reflux that wakes you mid-dream.

Which cheese is least likely to upset your sleep?

For people with lactose intolerance, aged hard cheeses such as cheddar, Swiss and Parmesan are the gentlest, because most of their lactose is gone by the time they’re ripe. Eating less, and earlier, probably does more than switching cheeses.

When should you see a doctor about nightmares?

See a doctor if nightmares happen often, leave you afraid to fall asleep or affect how you feel during the day. Nightmare disorder is treatable, and image rehearsal therapy is the AASM’s recommended treatment.