components of the mediterranean diet on a cutting board

Eat Right to Sleep Right

An expert in nutrition and public health explains the link between eating, drinking, and sleeping

February 28, 2024

People will try anything to get a good night’s sleep. What if the answer was in the fridge?

“Our research shows certain dietary patterns, foods, and nutrients are associated with better sleep,” says Marie-Pierre St-Onge, PhD, Director of Columbia's Center of Excellence for Sleep and Circadian Research.

There’s no single food that will lead to a perfect, restorative sleep for everyone. And, on the whole, diet is an individual matter; our bodies are as unique as our pillow choices and favorite snacks. But some foods provide nutrients we need to rest, and others are obstacles.

“Broadly, people who have diets that are high in fiber and low in saturated fat, sugar, and glycemic index values have the best chance of good sleep,” says St-Onge. Her team also found that people who have better sleep have better diet quality.

We asked St-Onge how improving diet leads to better sleep and which food and drinks to try.

What’s the relationship between food and sleep?

There’s a direct relationship between what you eat and how you sleep.

It’s well-known eating too much and too close to bedtime can be disruptive, and what you eat matters, too. Certain foods have nutrients that promote sleep. Other foods disturb sleep. Our research shows both men and women of all races and ethnicities experience better sleep when they have healthier, nutrient-rich diets.

Simply put, regularly eating a Mediterranean-style diet rules.

It’s well-known to be good for the health of your heart and brain. Now, we know a Mediterranean-style diet also leads to better sleep quality, fewer sleep disturbances, and better sleep efficiency. It also lowers the risk of insomnia, sleep apnea, and dementia.

And that’s not all. Lack of sleep leads to less healthy eating, which leads to poorer sleep, which leads to poor eating, which leads to...an unhealthy cycle.

Why do certain foods promote sleep?

Good sleep starts with regularly eating food rich in nutrients, including B vitamins, carbohydrates, lycopene, lutein, melatonin, selenium, serotonin, and tryptophan.

A rise in melatonin—the hormone that regulates sleep and your body’s circadian rhythms—signals sleep onset. If melatonin is not released, it’s harder to fall asleep. Various factors can be obstacles to melatonin release. Bright light is one, hence the recommendation to dim or turn off devices before bedtime.

Tryptophan, an essential amino acid you can only get from food, is the building block for melatonin. Foods containing high levels of tryptophan (relative to other amino acids and carbohydrates) can produce more melatonin.

  • Foods that contain both tryptophan and carbohydrates can lead to even more melatonin production (Usually, tryptophan competes with other amino acids for transport into the brain. When carbohydrates are present, they trigger insulin release, which leads to the uptake of amino acids to the muscles, freeing up transporters in the bloodstream that carry tryptophan to the brain).

Beyond tryptophan itself, converting tryptophan to melatonin requires enzymatic cofactors (molecules that help enzymes do their job as catalysts, enabling or speeding up a biochemical reaction). Some B vitamins and magnesium are essential cofactors. That means you want them in your diet, too.

Good nutrient sources:

  • Vitamin B5: Mushrooms, salmon, avocado, some seeds, legumes
  • Vitamin B6: Chickpeas, fish, chicken, bananas
  • Magnesium: Green leafy vegetables, nuts, seeds, legumes

Melatonin is also present directly in food, potentially adding to our body’s levels.

Which is better at promoting sleep, food or supplements?

The benefit of whole foods is that they come with various other healthy nutrients. So you’re improving your health through better sleep and better nutrition.

There are no studies comparing dietary sources of serotonin and melatonin to supplements for effects on sleep. We know melatonin supplements are not recommended for long-term use and may produce side effects. Perhaps more importantly, supplements are not regulated , and active ingredients can be much higher or much lower than what is claimed on the package.

Magnesium is having a moment; is there a relationship between foods high in magnesium and sleep?

More research is needed to claim magnesium helps improve sleep quality. But there’s no harm in choosing foods higher in magnesium content or trying supplements if you have sleep difficulties. I would not recommend taking magnesium supplements without speaking to your doctor first because magnesium at high doses can interfere with some medications.

What are the best foods to help you sleep?

We’re seeing diets with higher fiber, fruit, and vegetable intake—especially the more colorful produce —linked to better sleep.

Turkey is the most famous, but all meat (beef, chicken breasts, lamb, pork) and salmon, tuna, and clams are rich in tryptophan. So are pumpkin seeds, sesame seeds, sunflower seeds, nuts, beans, tofu, and brown rice. 

Are there foods people think will help with sleep but do not?

Many people think eating turkey explains why they get sleepy after a Thanksgiving meal. Although turkey has tryptophan, it is not an instantaneous sleep aid. It won’t make you fall asleep so close to mealtime.

Some people think alcohol will help them sleep. Alcohol is a sedative, and it may help some people fall asleep, but it also leads to lower sleep quality overall, with disturbed sleep later in the night.

Some people think hot water plus peppermint extract or mint tea are sleep aids, but no good research supports it. And the aroma of mint (menthol) can instigate alertness and focus.

That said, if you try these calming beverages and foods and find that you sleep well after eating or drinking them, there is no reason not to include them as part of your bedtime or winding down routine.

Let's talk about some foods that are having a moment on TikTok. Is lettuce water good for sleep?

No. TikTok videos suggest that soaking iceberg lettuce in hot water and then drinking the water will help you fall asleep. This has not been tested in humans (or animals), and this recommendation has no basis.

There is a study showing that bitter lettuce extract may have sedative effects in rats, but we do not know if it works in people. These extracts are alcohol soluble and do not represent what social media portrays.

There have been studies of lettuce seeds and pregnant women with insomnia, lettuce seed syrup, and people with breast cancer that show potential benefits for sleep in these populations.

What about tart cherry juice?

There is a video of a mocktail that contains tart cherry juice, magnesium power, and Olipop going viral on TikTok these days. Tart cherry juice and cherry fruits have been studied in randomized, placebo-controlled trials and have been shown to produce sleep benefits in a variety of people. Although those are small-scale studies, findings are consistent among them. And there is biological plausibility: One study found that melatonin levels increased in people consuming tart cherries. As mentioned above, magnesium is necessary for melatonin production, so this ingredient could also contribute to the sleep-enhancing effects of the mocktail. Finally, Olipop is a low-sugar soda that contains plant fiber and prebiotics and could improve gut health, which also has implications for sleep.

Another possible improvement in sleep from this mocktail is the lack of alcohol. If this beverage replaces alcohol in your pre-bedtime routine, and you get the best sleep ever, go for it! Just be mindful of magnesium over-supplementation.

What research is needed to bring public health attention to the food-sleep relationship?

Quite a bit.

We need studies that establish mechanisms of action—the biochemical interactions that create the better sleep effect—to support existing population-based studies showing the role of diet on sleep. Measuring tryptophan metabolism, for example.

We need controlled feeding studies in adults with sleep difficulties. Controlled means research dietitians or nutritionists design menus and prepare and provide all food consumed so measurements and data are precise.

There is value in studies that focus on one food to eat as a ‘dietary supplement.’ Still, we need more studies of whole dietary patterns—a person’s complete, regular diet—incorporating multiple sleep-promoting foods and nutrients.

We also need to evaluate sleep from different angles in those studies. This means taking objective measures via devices that can provide information on sleep duration, depth, and arousals and asking individuals about their sleep experience. Because, at the end of the day, if your watch tells you that you’ve had the best sleep ever and have a great sleep rating, but you still feel that you’re getting lousy sleep, then you’re not going to have the same health benefits as someone who wakes up feeling refreshed and energized.

References

Marie-Pierre St-Onge, PhD is the Director of Columbia's Center of Excellence for Sleep and Circadian Research and an Associate Professor of Nutritional Medicine at CUIMC.