Sleep improved by tryptophan and melatonin intake in diet and supplements, says study review

30 Mar 2020 --- Nutrients such as tryptophan and melatonin consumed through food may have a positive effect on sleep metrics, according to a new Australian study. It set out to establish the link between diet and sleep in healthy individuals, which is generally less researched in comparison to studies concerning patients with sleep-related disorders. As simple dietary changes to increase tryptophan and melatonin intake via food items were found to improve sleep quality, the study affirms that its findings are an important step in determining diet-related guidelines for general populations.

“The relationship between sleep and diet has gained considerable interest. However, it has largely focused on how diet can increase sleep for those with sleep-related disorders and co-morbidities, such as depression. Our findings suggested even in adults without clinically diagnosed sleep conditions, diet can influence sleep quality,” study author Dr. Saman Khalesi, Senior Lecturer at Central Queensland University, Australia, tells NutritionInsight.

He highlights that this research has become particularly relevant for the current climate where sleep may be impacted by the stress of COVID-19. By making small dietary changes, individuals may be able to improve their sleep and consequently help maintain their immune health.

“It should be noted that sleep quality depends on individual factors, such as stress, health status and lifestyle, as well as environmental factors which can influence sleep quality. Diet is just one of the factors influencing sleep,” Dr. Khalesi explains.

The review found that supplements containing zinc, vitamin B, polyphenols and crocetins have proven effective in improving sleep quality.Food for sleep
The given review identified four main themes in 32 studies previously researching the link between sleep and diets, namely tryptophan consumption and tryptophan depletion, dietary supplements, food items and macronutrients. Dr. Khalesi affirms that literature investigating the effect of tryptophan-rich or depleted diets on sleep quality has been around for over two decades. “However, these studies usually have conflicting findings with a specific focus on populations with severe sleep-related disorders,” he comments.

The review found that supplements containing zinc, vitamin B, polyphenols and crocetins have proven effective in improving sleep quality. Dr. Khalesi highlights, however, that nutrients are more likely to benefit health when consumed as part of a balanced diet. “If dietary changes, such as increased fiber intake, increased carbohydrate and decreased fat intake, or consuming seafood as part of a balanced diet are not possible, then supplements are still useful for promoting sleep.”

Recently on World Sleep Day, NutritionInsight highlighted nutritional supplement companies such as Pharmactive, whose Spanish saffron-based ingredient affron can help reduce overall insomnia by 25 percent and induce restorative sleep even at very low doses. Having paired melatonin with cannabidiol (CBD), Charlotte’s Web by the Stanley Brothers created CBD Gummies: Sleep, which integrates hemp’s naturally occurring phytocannabinoids together with melatonin to support sleep quality and duration.

Milk, eggs, cheese, chicken and fish contain tryptophan and can be included in a balanced diet as a way to promote better sleep. Melatonin is present in Spanish Jerte Valley cherries, grains such as rice and oats, and a variety of nuts, including walnuts and peanuts. “However, it is important to note that large dietary changes can be detrimental to sleep and health. Small dietary adjustments can be helpful,” Dr. Khalesi flags.

He concludes by underlining the importance of future studies to consider the “every day” factors that may influence what and when we eat. Some variables include work schedules, physical and mental health, light exposure, physical activity and family life. “All of these factors may impact our sleep and our ability to make dietary changes,” he adds.

By Anni Schleicher