Does Cheese Give You Nightmares?

Before you skip dairy completely, look at other options, experts say

Kristen Fischer,

AARP

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Published August 15, 2025

Maryam Khaleghi Yazdi

If a glass of milk before bed seems to help you sleep better, guzzle on. But if you feel that dairy before bed interrupts your sleep — or leads to nightmares — you may be right, according to a new report.

Survey data published June 30 in Frontiers in Psychology showed a link between nightmares and lactose intolerance, a condition that can become more common with age. The survey data showed that the worse the subject’s lactose intolerance was, the more intense the nightmares they reported.

Cheese has been thought to be the culprit behind nightmares, which is why Tore Nielsen, lead author and a professor at the University of Montreal, wanted to see if there was any actual link. Though the reported association could explain why some people experience nightmares persistently, experts say you should think before you ditch dairy as a way to reduce upsetting dreams.

Lactose intolerance tied to nightmares

Nielsen led a team that surveyed 1,082 college students about their sleep quality, eating habits, physical and mental health, and relationship with food.

Among participants, about 5 percent of students thought what they ate was related to their dreams, says Marie-Pierre St-Onge, a professor of nutritional medicine at Columbia University Irving Medical Center who wasn’t involved in the research.

The people who reported they had severe stomach symptoms from lactose intolerance were more likely to report more intense nightmares, which were self-reported using a nightmare score. Higher nightmare index scores were also linked to people who reported having food allergies, the data showed.

Women were more likely to report poor sleep and nightmares, and nearly twice as likely as men to report a food intolerance or allergy, according to the report.

Unlike lactose intolerance, which is when you don’t make enough lactase — the enzyme that breaks down lactose—a milk allergy is an immune system response to milk proteins that can be life-threatening.

Results showed that about 40 percent of students said that their diet affected their sleep quality — about half reported that it was for the better, and the other half said food made things worse. Among respondents who believed that food affected their dreams, about 31 percent said sweets were the culprit and 22 percent said dairy was to blame.

Nielsen said that checking for lactose intolerance could alert people to avoid a certain food and thwart sleep interruptions.

Questioning the link

The percentage of students who thought their food choices affected their dreams was a really small amount relative to the total number of respondents, she says. Students surveyed noted changes in dreams and nightmares, but didn’t specify what they changes were, St-Onge notes. Also, the students received a higher grade for participating in the survey, which introduced a bias, she adds.

The average participant age was about 20 years old, so the data can’t be generalized for older adults, says Chris Cifelli, senior vice president of nutrition research for the National Dairy Council.

Sharon Palmer, a registered dietitian nutritionist from Ojai, California, saysthe study shows that many people think food can interfere with their sleep, which makes sense. “When you have gastrointestinal issues, it can definitely interfere with a good night’s sleep because of the discomfort you may experience,” she says.

She added that that the study doesn’t prove that dairy causes nightmares, it only shows a reported link between the two things. The study wasn’t robust enough to show that dairy or lactose intolerance actually causes nightmares, Palmer says.

Understanding lactose intolerance and age

Lactose intolerance risk increases with age, because there’s a natural decline in activity of the lactase enzyme that breaks down lactose, St-Onge explains.

Specifically, food can remain in your gut for longer as you age, which contributes to gastrointestinal issues. This may increase the opportunity for bacterial fermentation which leads to gas and abdominal discomfort, St-Onge says.

People may also eat or drink less dairy as they get older, which could make it tougher to maintain lactase activity, she says. Continuing to consume dairy could reduce the risk that lactose intolerance becomes a problem, though it’s not totally preventable, St-Onge says.

“As we age, we can have an increase in digestive issues, such as bloating, gas, diarrhea and this also includes intolerance to dairy products,” says Palmer. “The digestive system is just not working as efficiently as it once was.”

Like Nielsen, St-Onge advises addressing lactose intolerance, but she doesn’t think this study shows nightmares are a sign of it in older people.

“I don’t think cheese will cause older adults to have bad dreams,” St-Onge says.

How food may affect sleep

The study raises the question whether people may sleep worse due to an unhealthy diet, or they may consume an unhealthy diet due to sleep issues — the science isn’t totally clear.

Researchers don’t quite know how foods affect dreams, St-Onge says. “Foods can cause sleep disturbances that may make it easier for you to recall dreaming, for example, by causing you to awaken in rapid-eye movement (REM) sleep, the stage of sleep in which we dream,” she says.

Age-related sleep changes usually reflect shifts in circadian rhythms and disturbances due to nighttime awakenings. That is, you may want to wake up and go to sleep earlier, St-Onge points out. As you age, there is also a decrease in the time spent in the REM phase of sleep.

A diet for better dreams

If you have lactose intolerance, skipping dairy may not be the best bet, Cifelli and St-Onge warn.

Some evidence shows that milk can promote sleep due to the tryptophan — something St-Onge highlighted in her 2023 study.

If you think milk disturbs your sleep or upsets your stomach, opt for lactose-free dairy milk. It includes the same essential nutrients in regular cow’s milk, such as protein, vitamin D, calcium, zinc, selenium and B vitamins. Many cheeses contain minimal amounts of lactose, and yogurt with live and active cultures to help digest lactose is often easier to digest.

Dairy foods like milk, cheese and yogurt provide critical nutrients many Americans struggle to get enough of, including calcium, vitamin D and potassium along with other vitamins and minerals, Cifelli explains. Plant-based milks often don’t stack up nutritionally to cow’s milk, though some fortified soy milks have the same nutritional profile as cow’s milk, he adds.

If lactose is the issue that you think may be causing your nightmares, try lower-lactose dairy options such as cheddar, Swiss, mozzarella, gouda and cottage cheeses, Cifelli offers. “Yogurt is lower in lactose than dairy milk, and its live and active cultures help break down lactose, which can make it easier to digest,” Cifelli adds. Some people also find that kefir, similar to a thin yogurt, is easier on their stomach than milk. Another reason not to skip dairy completely: It may support gut health, research shows.

Talk to your doctor if you experience stomach symptoms after consuming dairy, St-Onge suggests. Preventing gastrointestinal distress will likely do more to improve sleep than avoiding dairy before going to bed, she says.

A well-balanced diet is important for providing the high-quality protein and essential nutrients needed for bone, muscle and immune health to support healthy aging, Cifelli adds. This type of diet is also linked to fewer sleep disruptions, a 2025 study finds.

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Kristen Fischer is a contributing writer at AARP based at the Jersey Shore. She has also written for Health, WebMD, and McKnights and is the author of Zoo Zen: A Yoga Story for Kids.