What Happens to Your Dreams When You Eat Dairy Before Bed

If you like to drink a glass of warm milk before bed, it might interfere with your sleep. A recent study found a link between dairy consumption at night and bizarre and disturbing dreams.

The Link Between Dairy Products and Nightmares

The study included 1,082 participants who answered questions about how certain foods affect their sleep and dreams. Desserts and dairy products, such as milk, cheese, and yogurt, were most associated with nightmares.

Eating too close to bedtime and ignoring hunger or fullness cues also contributed to worse nightmares for the participants. Food-fueled nightmares and sleep issues were especially problematic in people with lactose intolerance. 

Lactose-intolerant people had the most severe gastrointestinal symptoms, including gas, bloating, and cramping, and they had the worst nightmares, according to Tore André Nielsen, PhD, lead author of the study and a psychiatry professor at the University of Montreal.

Nielsen said that GI symptoms at night can influence dreams, so can bodily sensations like menstrual cramps, pressure on the limbs, and pain.

Why Might GI Issues Lead to Nightmares?

Previous research has linked GI conditions, like stomach ulcers, gastroesophageal reflux disease (GERD), and irritable bowel syndrome (IBS), to poor sleep quality.

There are a few theories why GI issues might disrupt sleep and lead to nightmares.

“If you eat something that causes gastrointestinal distress, that fragments your sleep, and the sleep fragmentation leads to more dream recall, especially recall of dreams that are disturbing,” said Jennifer L. Martin, PhD, a spokesperson for the American Academy of Sleep Medicine and professor of medicine at the David Geffen School of Medicine at UCLA, who was not involved with the study.

When sleep quality is poor, people tend to remember disturbing dreams more clearly, she added.

Another theory is that nighttime GI symptoms may increase anxiety and depression, which in turn could influence dreams.

“It has been well documented that stressful situations experienced by a subject can trigger nightmares. Along the same lines, it may turn out that consuming dairy products that are not tolerated by the body may induce a type of stress that triggers nightmares. Unfortunately, it’s just a hypothesis,” Thomas Kilkenny, DO, director of the Institute of Sleep Medicine at Northwell’s Staten Island University Hospital, told Verywell in an email.

Should You Stop Having Dairy at Night?

The study doesn’t prove a cause-and-effect relationship, so it’s unclear whether dairy products like ice cream, milk, or cheese directly cause nightmares. Still, because sweets and dairy were strongly linked to bad dreams, people with lactose intolerance or food sensitivities may want to avoid certain desserts before bed.

Based on the results, Martin said, the worst bedtime snack would be ice cream.

Keeping a sleep diary can help track patterns between your eating habits and sleep quality. If you notice that you tend to have nightmares after eating dairy, you should try to avoid those foods before bed, Kilkenny said.

“It would be interesting to see if the supplement lactase—a treatment for the GI distress of lactose intolerance—would decrease the degree of nightmares,” Kilkenny added.

Other Ways to Improve Sleep Quality

Chronic sleep issues don’t always get resolved from minor changes, like eliminating one food, according to Martin.

Other ways to improve sleep quality include not drinking alcohol and caffeine at night, keeping a regular sleep-wake schedule, exercising, and avoiding screen time too close to bed.

“When I have people who have chronic, disturbing dreams or nightmares, we try to clean up their sleep, and one of the things that we focus on more than specific foods is just not eating big, heavy meals close to bedtime,” Martin said.