It is increasingly clear that we must take care of our sleep to take care of our health. When sleep fails, many other things begin to fail. We recover less well from exercise and injuries, our skin loses its elasticity, we age faster, our immune system weakens and we get sick more often, and the risk of cardiovascular disease, diabetes, obesity, depression and cognitive decline are increasing.
Sleep hygiene, such as a regular schedule, sleeping in the dark, or avoiding stimulants and screens before bed, are the first steps. However, diet, what we eat, but also when we eat, have a huge influence on the quality of sleep, which we often neglect.
More and more scientific studies are establishing a relationship between what we eat and how we sleep, since certain foods and meal times can alter circadian rhythms, metabolism and neurochemical processes involved in sleep.
Tell me what you eat and I’ll tell you how you sleep
The quality of macronutrients present in the daily diet has a direct impact on nighttime rest. For example, high consumption of carbohydrates and refined sugars, especially high doses contained in sweets and sugary drinks, can disrupt sleep, especially before bed.
Foods cause rapid spikes in blood sugar followed by sharp drops. When blood sugar drops, alarms are triggered in the body, which activate hormonal responses such as the release of cortisol, a hormone incompatible with rest, since it is also the hormone responsible for waking us up in the morning. Among other things, a recent controlled study found that diets high in carbohydrates and high glycemic load are associated with an increased risk of insomnia.
“At night, insulin, the hormone that metabolizes sugar, is more inactive,” explains Dr. Emilio Gómez Cibeira, head of the sleep unit at Ruber Hospital in Madrid. “If we consume a lot of sugar late at night, sleep will be less good.”
At night, insulin, the hormone that metabolizes sugar, is more inactive. If we consume a lot of sugar late at night, sleep will be worse
Emilio Gomez Cibeira
— head of the sleep unit at Ruber Hospital in Madrid
On the other hand, complex carbohydrates, such as those found in vegetables, whole grains and legumes, can promote sleep by providing a more stable release of energy and stimulating the production of serotonin, a precursor to melatonin, the hormone that regulates sleep. sleep-wake cycle. For its part, adequate consumption of proteins, especially those rich in tryptophan, such as eggs, fish and seeds, can improve the quality of sleep by facilitating the synthesis of serotonin. In general, diets high in saturated and trans fats, high in sugar, and low in fiber have been associated with more fragmented and lower quality sleep, with more awakenings and less deep sleep.
“For example, nuts are foods rich in tryptophan, white meats, like chicken or turkey, or fish, all fantastic,” says Dr. Gómez. “These are not foods that will put us to sleep, but they can promote the synthesis of the body’s natural hormones.”
When to eat to sleep better
Meal timing is as important for sleep as the content of the food. Eating too much, especially foods high in fat, sugar or spices, shortly before bed can cause gastrointestinal discomfort such as reflux, which disrupts sleep in the middle of the night. Additionally, late meals can disrupt the body clock by altering melatonin secretion and nighttime metabolism.
According to Dr. Gómez Cibeira, “you should avoid large dinners shortly before bedtime and try to eat dinner a few hours before going to bed,” he advises. “But of course the problem is that we live in Spain and we have a time zone that does not correspond to the meridian we are in. The normal thing would be to go to bed at ten o’clock and have dinner at seven o’clock, but for any Spaniard it’s a snack,” he comments.
Foods rich in tryptophan won’t make us sleepy, but they can promote the synthesis of the body’s natural hormones.
Emilio Gomez Cibeira
— head of the sleep unit at Ruber Hospital in Madrid
On the other hand, prolonged nighttime fasting can promote better sleep. This means stopping eating several hours before going to sleep. Studies suggest that eating dinner at least three hours before bed allows the digestive system to finish its task, which can improve sleep quality. Likewise, following a daytime diet, where the highest caloric intake is concentrated in the early hours of the day, can help synchronize circadian rhythms.
Alcohol and caffeine
Consuming caffeine to wake you up in the morning and alcohol to help you sleep at night is a particularly harmful habit, especially the latter. Caffeine, present not only in coffee but also in tea, chocolate and especially in high doses in energy drinks, blocks adenosine receptors, a molecule which promotes drowsiness.
Although the effects of caffeine are most intense in the first few hours after consumption, its half-life is around five hours, meaning it takes ten hours to be completely eliminated from the body. That espresso coffee at four in the afternoon, or even worse, after dinner, can keep us from falling asleep if we intend to sleep at eleven in the evening.
Alcohol has a more subtle, but also more harmful, effect. Its effect is calming, so it can cause drowsiness. However, drinking before bed reduces sleep quality, reduces deep sleep stages, and causes more nighttime awakenings. In the medium term, alcohol produces abnormalities in circadian rhythms, reduces total sleep duration and can cause snoring and sleep apnea.
The effects of caffeine are most intense in the first hours after consumption; its half-life is about five hours, which means it takes ten hours to be completely eliminated from the body.
Improving sleep with diet
Cleansing our diet of ultra-processed foods can be an effective tool for optimizing our nighttime sleep. “In Spain it is not that difficult to have a healthy diet,” explains Dr. Gómez. “Fast food and industrial pastries are terrible for sleep,” he warns.
A diet rich in fruits, vegetables, lean proteins, and healthy fats, typically associated with what we call the Mediterranean diet, has shown significant benefits in population studies on sleep quality. One possible explanation is that following this diet regulates inflammation levels, which contributes to restful sleep.
Additionally, certain micronutrients are essential for sleep. Magnesium, found in foods like spinach, almonds and seeds, as well as in supplement form, has a relaxing effect on the nervous system because it interacts with GABA receptors, the neurotransmitter that induces calm in the brain and promotes sleep. On the other hand, zinc and vitamin D, found in oily fish and dairy products, have also been linked to better nighttime sleep.
Finally, a nighttime ritual including relaxing infusions, such as chamomile or valerian, can also help us prepare the body for rest.
*Darío Pescador is editor and director of Quo Magazine and author of the book the best of yourself Published by Oberon.