We all know that consuming five cups of coffee in one afternoon or an energy drink right before bed can lead to terrible sleep. But as it turns out, our diet can affect our sleep, too.
Some unexpected foods can give us a restful night of deep sleep, while others can leave us tossing and turning for hours. We talk to experts about the foods and drinks that are likely to disrupt your sleep, as well as those that can help you get some much-needed rest.
Avoid coffee, wine, beer and chocolate 4 to 6 hours before bedtime
Caffeine wakes you up by blocking a hormone called adenosine – adenosine makes you sleepy. Drinking coffee or tea in the morning can make you feel alert and ready for the day, but drinking it close to bedtime can make it harder to fall asleep.
“Caffeine often makes it harder to fall asleep and can also contribute to poorer sleep quality,” says Erica Jansen, an assistant professor of nutritional epidemiology at the University of Michigan who primarily studies sleep and nutrition. “Alcohol and caffeine consumed right before bedtime are probably the worst offenders. It’s best to avoid both substances 4 to 6 hours before bedtime.”
Coffee, tea and sodas like Coca-Cola are known to contain caffeine, but foods and drinks like chocolate, kombucha and snack bars also often contain the stimulant.
Why alcohol and curry are a recipe for a bad night
Spicy foods like wasabi, chilies, kimchi, and harissa can affect your sleep quality. This is because these foods contain a chemical called capsaicin. Not only does capsaicin cause a burning sensation in your mouth, but it also increases your internal body temperature, which can disrupt your body’s natural cycles for signaling to itself that it’s time to sleep.
“Spicy food affects sleep in three ways. It can irritate the lining of the digestive tract, causing reflux and intestinal discomfort. It also increases our body temperature, which needs to be a little lower for restful sleep, and finally, it can trigger the release of cortisol (the stress hormone), which can keep us awake,” explains Sophie Medlin, nutritionist and chair of the British Dietetic Association for London.
And if you wash down the curry with a beer, things get even worse.
Alcohol may make it easier to fall asleep, but it may affect sleep quality. This is because it shortens rapid eye movement (REM) sleep and may cause you to wake up more often during the night.
“Although alcohol can help you fall asleep faster, it worsens overall sleep quality and leaves you feeling unrefreshed,” says Jansen.
Sardines and kiwi can make us sleepy
“Sleep is triggered by a hormone called melatonin, which, like all hormones, requires certain nutrients to be produced. The nutrients we need to produce melatonin include tryptophan, an amino acid, vitamin B6, which helps convert tryptophan into its active form, and magnesium and zinc,” says Medlin.
Dairy products such as milk and eggs, whole grains, and nuts are all high in tryptophan. They also contain magnesium and B vitamins, which help the body use tryptophan, which in turn promotes the production of melatonin.
Fatty fish like salmon and herring contain omega-3 oils, healthy fats that promote serotonin release. This in turn promotes the production of melatonin. Sardines also contain magnesium.
Tart cherry juice and other berries can increase melatonin levels and are rich in magnesium. Some studies have also found that kiwis can help treat insomnia.
Experts say you can eat these foods a few hours before bedtime, but in general they recommend eating a healthy, balanced diet, not focusing on individual ingredients, and sticking to set meal times.
The cheese plate can prevent deep sleep
Foods containing saturated fats can lead to a reduction in the type of sleep known as deep sleep, which is considered the most restorative phase of sleep and is important for metabolism, the immune system, tissue repair and memory consolidation.
Foods that contain saturated fats include processed meats such as bacon and sausage, most cakes and cookies, cheese, butter, ice cream and many others. They are digested and metabolized by the body more quickly than other food groups, and eating them before bed can cause you to wake up more often during the night, Jansen says.
Simple carbohydrates like white bread, pasta, white rice, sugary drinks and sweet treats like candy and cookies can have the same effect, she adds. “Taken together, these foods can make it harder to fall asleep and cause you to wake up more often during the night. Unfortunately, late-night foods often contain all or most of these components.”
Avoid eating after 9pm
We indulge in unhealthy treats every now and then, so by eating them well before bedtime, we can minimize the impact on our sleep.
“The digestive and metabolic process requires your body to stay on to some degree, which means sleep quality will be compromised,” says Medlin. “It’s helpful to remember that we consider 9 p.m. to be our ‘biological night,’ meaning our body is preparing for sleep and doesn’t really want any additional food after 9 p.m.”
