If you’ve ever struggled to get a good night’s sleep, you’re not alone. Sleep issues are a global health concern, with approximately one-third of American adults falling short of the recommended amount of rest each night.1 Poor sleep doesn’t just leave you feeling groggy; it’s linked to a higher risk of chronic diseases like heart disease and diabetes, weakened immune function, and reduced overall quality of life.2 What if the secret to better sleep was as simple (and delicious) as adding walnuts to your favorite dishes? New clinical research suggests that nutrient-dense, plant-forward foods like walnuts may hold the key to naturally improving sleep quality.
The Science Behind Walnuts and Sleep
A groundbreaking study published in Food & Function by researchers from the University of Barcelona has shed light on the potential sleep-supportive benefits of walnuts.3 This randomized controlled trial evaluated the effects of consuming 40 grams of walnuts daily (about 1.5 ounces or large handful) with dinner over an eight-week period. The study involved 76 healthy young adults, primarily women aged 20-28, who completed both walnut intervention and control phases in a crossover design.
The results? Eating walnuts was linked to increased levels of 6-SMT, a biomarker of melatonin, which is a hormone that helps regulate our sleep-wake cycle. Participants also reported measurable improvements in their overall sleep quality when consuming walnuts, including:
- Shorter sleep latency: The time it took participants to fall asleep decreased.
- Improved sleep efficiency: The percentage of time spent in bed actually sleeping increased.
- Reduced daytime sleepiness: Participants reported feeling more alert and less groggy during the day.
The researchers suggest that walnuts’ unique combination of sleep-supportive nutrients, such as tryptophan, melatonin, magnesium, and B vitamins, may help explain these positive outcomes seen in the study.
The Nutritional Link Between Walnuts and Sleep
The naturally occurring combination of nutrients found in walnuts may work together to support the body’s sleep processes, offering a potential explanation for the study’s findings. Key sleep-supportive nutrients in walnuts include:
- Tryptophan (84.6 mg)
- Plant-based melatonin (118 ng)
- Magnesium (45 mg)
- B vitamins (0.2 mg each vitamin B5 and vitamin B6).4
Interestingly, the tryptophan-to-competing amino acid (CAA) ratio in walnuts is 0.058, which is favorable for allowing tryptophan to cross the blood-brain barrier and be converted into melatonin.3 This makes walnuts a particularly promising food for supporting sleep.
Recipes to Incorporate Walnuts into Your Daily Routine
- Walnut Pear and Avocado Bowl: This refreshing, nutrient-packed dish combines creamy avocado, juicy pears, and crunchy walnuts for a balance of flavors and textures.
- Walnut Chocolate Bliss Balls: Craving something sweet? These no-bake treats made with walnuts are the perfect indulgence.
Other Tips for Better Sleep
While walnuts are a promising addition to your sleep routine, they’re just one piece of the puzzle. Here are some tried-and-true tips for supporting good sleep, based on both science and personal experience:5
- Stick to a consistent sleep schedule by going to bed and waking up at the same time each day.
- Create a calm, quiet, and cool environment in your bedroom to promote relaxation.
- Power down electronic devices at least 30 minutes before you plan to sleep.
- Steer clear of heavy meals and alcohol close to bedtime.
- Limit caffeine intake later in the day, especially in the afternoon and evening.
- Stay active with regular exercise and support your sleep with a balanced, healthy diet.
- Avoid caffeine and alcohol close to bedtime. Instead, opt for a light snack that includes sleep-friendly foods like walnuts.
Final Thoughts
With sleep being such a critical component of overall health to feel good, finding evidence-based support to get those elusive, quality zzz’s is incredibly important. Walnuts, with their profile of sleep-supporting nutrients, offer a simple and delicious way to support better sleep. Whether you’re enjoying them in a Walnut Pear and Avocado Bowl, snacking on Walnut Chocolate Bliss Balls, or simply eating them by the handful, walnuts are a versatile and nutritious addition to any diet that is focused on supporting quality sleep. Sweet dreams!
About the Author
Lauren Manaker is an award-winning registered and licensed dietitian, three-time book author, respected nutrition expert, and California Walnuts partner. She holds a Bachelor’s degree in Food Science and Human Nutrition from the University of Florida and a Master’s degree in Clinical Nutrition from Rush University in Chicago. She is a contributor to many media outlets, including Good Housekeeping and Eating Well, with a special focus on women’s health issues and “busting” nutrition myths found on the internet and on social media. Throughout her career, Lauren has been involved with the Academy of Nutrition and Dietetics, where she has held leadership roles, and frequently spoken at their conferences. She also serves on the Advisory Board for the University of South Carolina’s dietetic internship and Master’s program.
References:
- National Institute of Health. What Are Sleep Deprivation and Deficiency?. March 24, 2022. Available at https://www.nhlbi.nih.gov/health/sleep-deprivation
- National Institute of Health. National Library of Medicine. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Available at https://www.ncbi.nlm.nih.gov/books/NBK19961/.
- Zerón-Rugerio MF, Ibarra-Picón A, Diez-Hernández M, Comas-Basté O, Pérez-Cano FJ, Cambras T, Izquierdo-Pulido M. Daily walnut consumption increases 6-sulfatoxymelatonin urinary levels and can improve sleep quality: a randomized crossover trial. Food Funct. 2025 Sep 15;16(18):7023-7035. doi: 10.1039/d5fo00971e.
- https://walnuts.org/news/young-adults-consuming-walnuts-reported-improved-sleep-quality-new-study-finds/
- Centers for Disease Control and Prevention. About Sleep. May 15, 2024. Available at https://www.cdc.gov/sleep/about/index.html
