One of the simplest and most effective ways to improve the quality of one’s sleep is to improve the quality of the diet. One-third of American adults don’t get enough sleep on a regular basis, according to the Centers for Disease Control. Not surprisingly, people are desperate to try anything—prescription sleeping pills, over-the-counter sleep aids, herbal supplements, teas, tonics, and meditation apps—in their quest for better rest.
But there’s a solution that’s often overlooked, and it may be sitting right there in your kitchen: the right foods. Just as diet can have an effect on the systems in the brain and body that control blood pressure, cholesterol, weight, and other aspects of health, it can affect the processes that regulate sleep. There is existing evidence that improving your diet can lead to better sleep. The foods and dietary patterns that are associated with better sleep tend to be lower in “glycemic index” (less effect on blood sugar levels), low in saturated fat, low in added sugars, and high in fiber. Conversely, foods with the opposite attributes can prevent a good night’s sleep.D
Diet Strategies That Enhance Sleep
When you build your diet around foods that fit those criteria, you end up with something that looks like the Mediterranean diet—a way of eating that emphasizes plant-based foods, including lots of fruits, vegetables, legumes, whole grains, and healthy sources of fat (such as olive oil, nuts, and avocados), while limiting red meat, sweets, and refined carbohydrates (such as foods made with white flour). And indeed, studies examining the relationship between this pattern of eating and better sleep have shown promising results.
For example, a 2020 study published in the journal Nutrients followed more than 400 U.S. women for a year to see whether compliance with the Mediterranean diet affected their sleep quality. Those with the greatest adherence to this way of eating had 30 percent lower sleep disturbance scores (meaning they got more solid rest) than those with the lowest adherence.
Certain categories of foods—namely fruits, vegetables, and legumes—stood out for their positive effects on various measures of sleep quality. Legume consumption was associated with overall better sleep. And the effects were “dose-dependent,” i.e., the more servings of legumes they ate, the more significant improvement they had in sleep efficiency. Sleep efficiency is the ratio of how many hours you sleep to how many hours you spend in bed.
But it’s not simply that the Mediterranean diet necessarily has magic abilities to enhance sleep. It’s the healthy components of that way of eating—more fruits and vegetables, legumes, whole grains, and healthy fats. More likely, it provides focus on eating those foods in any predominantly plant-based diet. As an extra benefit, this dietary pattern reduces one’s chances of developing heart disease and cancer.
How Better Eating Leads to Better Sleep
There are several possible explanations for how a healthy plant-based diet enhances sleep: All of the foods plentiful in the Mediterranean diet are rich sources of fiber, which benefits the gut microbiome (bacterial content). The gut microbiome is thought to send signals that help to regulate circadian rhythms, i.e., sleep. Circadian rhythms, (the body’s naturally recurring biological daily clock). Additionally, the gut is involved in the synthesis of serotonin, a neurotransmitter that promotes better mood and is an important component for regulating sleep.
Higher fruit and vegetable consumption as part of a plant-based diet also means greater intake of beneficial compounds called polyphenols. Emerging research points to these compounds improving in sleep through their effects on the autonomic (involuntary) nervous system and can increase heart rate variability (the fluctuation in time between heartbeats). Higher heart rate variability is a sign you’re in a relaxed state and may be associated with better sleep quality. Some polyphenols also act directly on receptors in the brain that promote sleep.
Plant foods can even enhance the production of the sleep hormone melatonin. Legumes, soy, leafy greens, and seeds are all rich sources of tryptophan, an amino acid (a building block of protein) that the body uses to make melatonin. Turkey and dairy are often cited as the best sources of tryptophan. But the tryptophan in those high-protein foods isn’t actually synthesized as efficiently in the brain as the tryptophan from plant foods. That may be in part because you also need B vitamins and carbohydrates to process tryptophan—both of which you get when you eat a diet rich in fruits, vegetables, legumes, and whole grains.
Eating Habits That Can Disturb Your Sleep
In addition to leaving you feeling tired, not getting enough sleep affects various processes in your brain and body that can lead to unhealthy food choices. Sleeping too few hours may increase hormones that stimulate appetite as well as suppress those that signal satiety. At the same time, short sleep duration appears to activate the reward centers in the brain—increasing cravings for high-sugar, high-fat snack foods. If you have good sleep, you tend to make better choices in all aspects of your life—eating healthier foods, taking the stairs instead of the elevator, etc. And when you don’t have good sleep, you tend to go for the easier, less healthy choices—more processed foods, more snacks, more sugar, less exercise. And this vicious cycle may perpetuate itself. A habitually unhealthy eating pattern can in turn lead to more sleepless nights.
Along with obvious sleep-wreckers like alcohol and caffeine, foods that are high in fat, sugar, and saturated fat have been shown to negatively affect sleep quality. For example, one small study published in the Journal of Clinical Sleep Medicine, found that when participants ate more sugar, refined carbs, and saturated fat, it took them longer to fall asleep and they spent less time in the deep, restorative short wave sleep phase.
In another study, published in in the Journal of the American Heart Association, researchers looked at the diets and sleep quality of almost 500 women. They found that the women who reported the poorest sleep quality consumed over 400 calories more per day than those who routinely fell asleep in 15 minutes or less. Not only did the poor sleepers eat more calories per day, they also consumed more sugar, more saturated fat, and less fiber.
Can Specific Foods Help You Sleep?
Over the years there have been various studies of how eating individual foods could promote slumber. Although these studies were typically small in scale (and often funded by the food industry) they usually resulted in lots of splashy headlines touting the miraculous effect of certain foods—such as tart cherries or kiwis. But experts caution against looking to any single food as nature’s sleeping pill. The answer lies in the general approach advocated above.
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