Megan Meyer, PhD
Director, Science Communications, International Food Information Council
Good nutrition and a healthy diet touches so many different aspects of daily life, and sleep is no exception.
It’s recommended that adults over the age 18 get seven or more hours of sleep per night. Yet, according to the Centers for Disease Control (CDC), one out of three US adults usually get less than that. In addition, sleep problems have been a major issue during the COVID-19 pandemic. A recent systematic review and meta-analysis found that about 40% of people, including healthcare professionals, have had problems with sleep.
Since not getting enough sleep is linked with many chronic diseases and conditions, such as type 2 diabetes, cardiovascular disease, obesity and depression, focusing on ways to promote better sleep can lead to improved health. While there are a variety of strategies such as exercise, a consistent sleep routine and limiting electronic devices around bedtime that can support quality sleep, considering changes to what you eat and drink is a natural place to start.
Sleep is controlled by a variety of hormones in the body, specifically melatonin and serotonin. Melatonin helps regulate sleep and wake cycles while serotonin causes the body to make more melatonin. Tryptophan, an amino acid found in a variety of foods, is a precursor to melatonin and serotonin, which is why tryptophan-rich foods are often recommended for better sleep. In fact, studies have shown that low tryptophan levels in the diet can impair sleep. Some tryptophan-rich foods include meat, seeds, nuts, cheese, eggs and soy products.
Surprisingly, there’s not a wide range of tryptophan content among meats: turkey, chicken and beef have about 300 milligrams of tryptophan per 3-ounce serving. However, ounce for ounce, pumpkin seeds pack the highest tryptophan punch, with about 60% more tryptophan than turkey, chicken or beef. Fruits such as cherries and kiwis also contain these sleep-promoting hormones and amino acids. Clinical trials have shown that cherry and kiwi consumption improved sleep quality and duration.
Sleep hormones are regulated by micronutrients such as B vitamins. Vitamin B12 is involved in melatonin secretion and is naturally found in animal products like meat, fish, milk, cheese and eggs. Some foods like breakfast cereals and alternative milks like soy, almond, coconut and rice are fortified with vitamin B12. Another important B vitamin for sleep is vitamin B6 because of its critical role in the production of serotonin. The richest food sources of vitamin B6 include fish, organ meats, potatoes and other starchy vegetables, non-citrus fruit and fortified cereals.
In addition to what should be included in the diet, there are a few things that should be limited or avoided. The timing of meals can influence sleep. Studies have shown that eating large meals before bedtime can cause indigestion, acid reflex and heartburn, which can disrupt sleep. As a result, the CDC suggests avoiding large meals before bedtime to allow for digestion. The National Sleep Foundation offers a more specific recommendation to finish meals two to three hours before bedtime. Caffeine can also affect sleep habits. For optimal sleep, avoid consuming caffeine a few hours before going to bed and keep your daily caffeine intake to less than 400 milligrams. 400 milligrams of caffeine equates to about four cups of coffee, six ounces of espresso, eight cups of black tea or 13 cups of green tea. If you’re unsure how much caffeine is in common foods or beverages, check out the International Food Information Council’s caffeine calculator.
Adequate sleep is essential for optimal health, and one way to support quality sleep is to set up healthy eating habits that you can maintain over a long period of time. The 2020-2025 Dietary Guidelines for Americansemphasize the importance of building healthy and flexible patterns of eating. So, whether you choose to follow a vegetarian diet, Mediterranean eating style or something in between, the most important thing for you can do for good sleep and overall health is eat a varied diet full of fruits and vegetables, whole grains, unsweetened, fat-free and low-fat varieties of dairy and fortified soy alternative foods and beverages, lean protein and healthy fats.