May 23, 2023

Dear Melissa & Friends: Unpacking Diet and Sleep with Dr. Michael Breus

We’re all trying to sleep better. You now know how important sleep is to just about every marker of health. You’ve bought blackout curtains, keep your bedroom cool, and wear an eye mask to block out the light. If you’re like me, you also go to bed Toddler Early as often as you can, to try to sneak an extra hour or two of sleep into your week.

You probably also realize at least a few obvious ways that food and drink impact your sleep, like drinking alcohol, too much caffeine, or a big meal right before bed. But are there other ways that your diet might be helping or hurting your sleep in ways you didn’t realize? Are there any magic bullets for better sleep, when it comes to the foods you’re eating? Is tart cherry juice really going to cure my insomnia, like TikTok claims?

For questions like these, I turn to my friend The Sleep Doctor. Dr. Michael Breus is a clinical psychologist, diplomate of the American Board of Sleep Medicine, and a fellow of the American Academy of Sleep Medicine. Today, he’s going to help us explore some of the ties between our diets and sleep quality.

MU: Is there really such a thing as sleep “superfoods,” like tart cherry juice, pistachios, or kiwi? (I’ve seen all of those advertised on TikTok.)

Dr. Breus: There are, but to be honest, they’re not going to cure your insomnia. The foods you just named all are rich in natural melatonin (the “sleep hormone”). However, if you are a person without a melatonin deficiency (which is most of the world), then these will not really have much of an effect. 

Still, if you want to include melatonin-rich foods in your diet, look to fatty fish, nuts and seeds (especially walnuts, pistachios, almonds, and pumpkin seeds), and fruits and vegetables (grapes, strawberries, tomatoes, and peppers).

In addition, many herbs have been studied for their role in promoting sleep. Some experts hypothesize that these herbs may help regulate sleep through affecting the regulation of GABA, a chemical messenger in the body. Try herbal teas in the form of chamomile or valerian. (Note, there may be risks to using herbs, and herbs may interact with certain medications. Before taking any herbs or supplements that claim to promote sleep, speak with your healthcare provider.)

MU: Are there any foods that are good for sleep, or is that just marketing?

Dr. Breus: The impact of foods on sleep and sleep-quality is actually a pretty under-researched area, but there are a few things that we know: 

Protein is a natural sleep aid. Among their benefits for sleep, protein-rich foods can be a source of tryptophan, an amino acid that the body uses to make the sleep-facilitating hormone melatonin. A 2020 review of recent sleep-nutrition research found that higher sleep quality is associated with consuming a greater share of daily calories from protein. A 2016 study from Columbia University found that participants who ate meals high in protein and fiber (and low in saturated fats, sugar, and carbohydrates) experienced higher sleep quality and more time in deep sleep.

High-fiber diets may help us achieve deeper, more restorative rest. Fiber-rich diets have been associated with less time spent in light sleep and more time spent in slow-wave sleep (the deep, highly restorative sleep stage during which the body undertakes significant cellular rejuvenation and repair). A 2016 study from Columbia University found that a single day of low-fiber dietary consumption can have a negative impact on sleep that night. 

Research has also found that people who eat more servings of fruits and vegetables may sleep longer and get more restful sleep. Fruit and vegetable consumption has also been linked to better sleep quality and a reduced risk of insomnia. While it is difficult for researchers to pinpoint the exact reason for the sleep-promoting benefits of fruits and vegetables, a variety of these foods contain melatonin—a hormone central to sleep, our daily cycles of rest and activity, and the regulation of the body’s biorhythms. 

MU: Are there certain foods that mess with your sleep? 

Dr. Breus: A sugar-laden diet creates several problems for sleep. Sugar consumption is linked to restless sleeping, and more frequent nighttime awakenings. Sugar stimulates appetite, which can lead to more late-night eating that disrupts the soundness of our rest. It contributes to inflammation, and inflammation interferes with sleep. And excess sugar is harmful to gut health. Our gut microbiome plays a role in regulating sleep that we’re just beginning to understand, and it’s becoming increasingly clear that protecting the health of our gut can have a powerful benefit on sleep. 

Also, diets higher in saturated and trans fats have been linked to lighter sleep that’s accompanied by more frequent awakenings throughout the night. Saturated and trans fats often found in highly processed foods are linked to inflammation, which can undermine sleep. Fats play an important role in a healthful diet and a restful night’s sleep, but the type of fat in our diets matters a great deal. 

MU: Are there any universally sound recommendations when it comes to food and sleep? 

Dr. Breus: I ask my patients to stop exercising three hours before bed, stop eating two hours before bed, and stop drinking one hour before bed. It’s easy for them to remember, and it works well. Obviously avoiding things like caffeine, sugar, and alcohol before bed are recommended as well. 

Hydration is also a factor when it comes to sleep. Drinking more water and staying hydrated is generally associated with better sleep, which may suggest that being dehydrated can negatively impact sleep. To date, there is limited evidence that dehydration directly affects how well or how long a person might sleep. However, dehydration can affect a person’s health in other ways that may affect sleep, such as causing headaches. There may also be a connection between dehydration and obstructive sleep apnea (OSA), which involves lapses in breathing during sleep. 

MU: If you’re legitimately hungry an hour or two before bed, what should you eat to minimize the potential negative impact on sleep quality?

Dr. Breus: While you should not go to bed hungry, the body was not designed to digest lying down. Digestion also raises your body temperature, which can also disrupt sleep. If you are truly hungry before bed, I usually recommend a light snack which is 75% carbs and 25% protein. (An example might be an apple with nut butter.) 

One thing that some people like to do is load up on water to quell hunger pangs, which does not work well in the middle of the night. Limiting your fluid about an hour before bed (check with your doctor) is also a good idea. 

MU: Could even morning cups of coffee impact your sleep patterns later in the day? Are there any good rules of thumb when it comes to caffeine and sleep?

Dr. Breus: This is a complicated question, and is highly context-dependent. We know that consuming caffeine too late in the day can make it difficult to have a restful night of sleep. Common effects of caffeine on sleep include lengthening the time it takes to fall asleep, shortening the amount of time spent asleep, altering the time spent in deep sleep, and contributing to reduced sleep quality.

The stimulating effects of caffeine can last eight hours, if not longer. Every additional serving of caffeine extends this time, so the more caffeine a person drinks, the longer it will take for the effects of caffeine to wear off. However, how long it takes for the body to break down caffeine varies between individuals; some are faster metabolizers than others.

Three general tips I offer around caffeine and sleep include:

  • Stop drinking caffeine by midday. Drinking caffeine towards the beginning of the day can mean lower levels of caffeine in your body at night and fewer sleep disruptions.
  • Track your caffeine intake. Keeping track of how much caffeine you are drinking can help you understand your sensitivity to caffeine and how long it stays in your system. 
  • Decrease how much caffeine you drink. To avoid disrupted sleep, you may want to cut back on caffeine. It is a good idea to do this slowly, so try swapping highly caffeinated drinks for less-caffeinated options. Switching from coffee to tea or having decaffeinated versions of your beverage of choice can make a big difference. 

MU: What is one simple dietary tip you’d offer anyone who wants to sleep better tonight?

Dr. Breus: I’ll give you three: stop caffeine before noon, stop alcohol consumption three hours before lights out, and hydrate well throughout the day.

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