Melatonin

Written By Brittyn Coleman, MS, RDN/LD

What is Melatonin?

  • Melatonin is a hormone naturally produced in our brain in response to darkness. It helps control natural sleep-wake cycles and circadian rhythms. Individuals with ASD may have lower levels of naturally produced melatonin. Supplemental melatonin may help with sleep, anxiety, gastrointestinal dysfunction, and other behavioral concerns.

  • Melatonin is a hormone naturally produced in the pineal gland in our brain in response to darkness. The pineal gland then releases melatonin into the bloodstream where it plays a role in natural sleep-wake cycles and circadian rhythms. [1]

  • Melatonin is also produced in the gut, bone marrow cells, mast cells, lymphocytes, and epithelial cells. The role that melatonin produced from these cells plays is still largely unknown. [2]

  • Since a large proportion of melatonin production occurs in the gut, any type of gut dysfunction can lead to decreased levels of melatonin. 

  • Imbalanced melatonin production or release can greatly impact the ability to wind down for sleep, fall asleep, or stay asleep. (See the Sleep Issues note for more)

  • Tryptophan, an essential amino acid acquired in the diet from protein-rich foods, is a precursor to melatonin. 

  • Since melatonin is converted from serotonin, low levels of melatonin may signal low levels of serotonin as well. 

    • Serotonin is a key hormone that stabilizes our mood, feelings of well-being, and happiness. 

    • Therefore, sleep issues often go hand in hand with anxiety, depression, and aggression.

  • Research suggests that melatonin plays other important roles in the body beyond sleep such as: regulation of food intake and digestion, gut motility, protection against inflammation, metabolism, and reproduction. [2] 

    • Visit the research section below to learn more about melatonin and insomnia, anxiety, gastrointestinal function, and circadian rhythm.

 
 

Things That May Suppress Normal Production of Melatonin:

  • Artificial Light

    • Blue light

    • LED lights

    • Fluorescent lighting

  • Night shift work

  • Excess weight

  • Gastrointestinal dysfunction (see GI Issues for more)

  • Nutrient Deficiencies [1]

    • Folate

    • Vitamin B6

    • Vitamin B12

    • Magnesium

    • Zinc

    • Tryptophan

      • The nutrients listed above are necessary for the conversion of melatonin. These nutrients are commonly deficient in individuals with Autism.

 
 

Food Sources of Melatonin

Melatonin is a hormone produced naturally by the pineal gland in the brain. Below are dietary sources of melatonin. Even though the foods below are a source of melatonin, they contain melatonin in very minimal amounts. Therefore, if you are looking to increase melatonin levels or encourage sleep, a melatonin supplement might be a better option.

  • Fruits & Vegetables

    • Tart Cherry

    • Corn

    • Asparagus

    • Tomatoes

    • Pomegranate

    • Olives

    • Grapes

    • Broccoli

    • Cucumber

  • Grains

    • Rice

    • Barley

    • Rolled Oats

  • Nuts & seeds

  • Breastmilk & Cows Milk

    • Higher levels of melatonin have been found in milk secreted at nighttime. [1]

Is Melatonin Beneficial for Autism?

Melatonin & Anxiety

  • Recent studies have found that melatonin supplementation prior to an operation decreased anxiety levels. [5]

  • Since melatonin showed promise in decreasing anxiety prior to an operation and because anxiety is known to be linked to all types of sleep problems in children with autism, supplementing with melatonin could provide a way to reduce anxiety and encourage sleep. [5]

  • Despite these findings, there is no specific research on children with autism and the use of melatonin for anxiety. More research needs to be done. 

  • Read more about anxiety here

MELATONIN & GASTROINTESTINAL FUNCTION

  • Melatonin is produced within cells of the gastrointestinal tract in a higher concentration than what is found in the brain and bloodstream. Additionally, food intake and food composition are thought to control the production and release of melatonin by these cells. This suggests that melatonin could play a huge role in gut functioning. [5]

  • One study found that when adults with irritable bowel syndrome and sleep disturbances were given 3mg of melatonin, they had a decreased level of abdominal pain and increased pain threshold. [5]

  • These studies suggest that autistic individuals with sleep issues and digestive concerns may benefit from melatonin supplementation. 

MELATONIN & INSOMNIA

  • In a study of 125 children with Autism Spectrum Disorder, when behavioral interventions alone did not work to resolve sleep concerns, supplemental melatonin was found to decrease the length of time needed to fall asleep by roughly 40 minutes on average and increased the length of sleep by roughly 60 minutes on average. [6]

  • Supplemental melatonin may help children with Autism to fall asleep more quickly and sleep for longer lengths of time. [6]

Melatonin & Neuroprotection

  • Studies have shown that melatonin acts both directly and indirectly as an antioxidant to reduce oxidative stress. It does so by stimulating antioxidant enzymes, enhancing the activity of certain antioxidants, and protecting others from damage. [7]

  • Through these roles and their ability to easily pass through the blood-brain barrier, melatonin is thought to have a neuroprotective role in the brain, protecting against brain and nerve oxidative damage. [7]

  • Since nerve and brain inflammation has been linked to autism, melatonin may play a protective role against the progression of damage caused by inflammation in the brain.

CIRCADIAN RHYTHM AND MELATONIN ABNORMALITIES

  • One hypothesis for sleep issues in ASD is circadian-relevant gene anomalies resulting in biological and behavioral rhythm disturbances. [8]

  • A delayed melatonin rhythm and low melatonin amplitude have been hypothesized to be associated with a hard time falling asleep and night waking in children with ASD. [8]

  • Multiple investigators have identified lower levels of melatonin or a major metabolite of melatonin in either the urine, serum, or plasma of individuals with ASD. [8]

    • Keep in mind some children with ASD do not respond to melatonin and some families find that melatonin loses its effectiveness over time.

 
 

Supplementation

Although it is naturally occurring, some people may not produce enough or at the appropriate time to encourage sleep. In these cases, supplementation might be considered. 

Examples of common Melatonin supplements include:

Liquid

Capsule/Softgel

Spray

*A Note on Timing & Dosages:

  • Studies have shown that the timing of melatonin supplementation, not necessarily dosage, is more important for producing the best sleep results. [4]

  • The ideal timing for melatonin supplementation appears to be between 2-4 hours prior to bedtime. [4]

  • The dosages of supplemental melatonin varies greatly. It is best to start with a low dosage and to only use supplemental melatonin when needed and not on a daily basis.

  • Extended-release vs immediate-release melatonin

    • Immediate-release melatonin supplements may benefit those that have difficulty falling asleep. 

    • Extended-release melatonin supplements may benefit those that have difficulty staying asleep.


Potential Adverse Side Effects of Long-Term Melatonin Supplementation:

  • Supplemental melatonin may modify the immune response in such a way that there is a risk it may worsen symptoms of rheumatological conditions such as rheumatoid arthritis. [4]

  • Supplemental melatonin may inhibit the gonadotropin-releasing hormone (GnRH). [4]

    • In females, GnRH is a hormone responsible for triggering the secretion of two hormones that cause the ovaries to produce estrogen and progesterone. Therefore by inhibiting GnRH, melatonin may cause missed menstrual periods. [4]

    • In men, GnRH triggers the testicles to release testosterone. [4] Testosterone is important for muscle mass, fat distribution, bone mass, and sexual development. 

    • For these reasons, studies suggest melatonin may delay the onset of puberty in children. 

  • Most adverse side effects can be managed by appropriate dosing in accordance with normal circadian and under the supervision of a medical professional.

Melatonin Alternatives

Keep in mind some children with ASD do not respond to melatonin, it may cause grogginess or night terrors and some families find that melatonin loses its effectiveness over time. If this is your experience, you may want to consider other melatonin alternatives. 

  • Magnesium

  • Inositol

  • GABA

  • L-Theanine

  • Probiotics

  • Essential Oils: 

    • Lavender

    • Bergamot

    • Frankincense

    • Sandalwood

  • Herbal Options: *May not be appropriate for children.

    • Valerian Root*

    • Kava Kava*

    • Passion Flower*

    • Chamomile*

    • Hops*

When sleep issues arise it is advisable to first address behavioral strategies such as: a bedtime routine, avoiding stimulating drinks, such as soda, limiting video games and television around bedtimes. Visit the Sleep Issues note to learn more.

DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.

Note: All supplements are linked to Amazon for convenience, however, buying supplements on Amazon does not guarantee quality, as there are many “unverified resellers” selling nutrition supplements. To buy supplements that are verified to be sent directly to the consumer, you can create an account on the Autism Dietitian FullScript and search for the respective supplement under “Catalog”.

Authors

Brittyn Coleman, MS, RDN/LD, CLT

Sinead Adedipe, MS

  • [1] Peuhkuri K, Sihvola N, Korpela R. Dietary factors and fluctuating levels of melatonin. Food Nutr Res. 2012;56:10.3402/fnr.v56i0.17252. doi:10.3402/fnr.v56i0.17252

    [2] Chen CQ, Fichna J, Bashashati M, Li YY, Storr M. Distribution, function and physiological role of melatonin in the lower gut. World J Gastroenterol. 2011;17(34):3888-3898. doi:10.3748/wjg.v17.i34.3888

    [3] Meng X, Li Y, Li S, et al. Dietary Sources and Bioactivities of Melatonin. Nutrients. 2017;9(4):367. Published 2017 Apr 7. doi:10.3390/nu9040367

    [4] Masters A, Pandi-Perumal SR, Seixas A, Girardin JL, McFarlane SI. Melatonin, the Hormone of Darkness: From Sleep Promotion to Ebola Treatment. Brain Disord Ther. 2014;4(1):1000151. doi:10.4172/2168-975X.1000151

    [5] Gagnon K, Godbout R. Melatonin and Comorbidities in Children with Autism Spectrum Disorder. Curr Dev Disord Rep. 2018;5(3):197-206. doi:10.1007/s40474-018-0147-0

    [6] Gringras, P., Nir, T., Breddy, J., Frydman-Marom, A., & Findling, R.L. (2017). Efficacy and safety of pediatric prolonged-release melatonin for insomnia in children with autism spectrum disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 56(11), 948-957. doi: 10.1016/j.jaac.2017.09.414.

    [7] Esposito E, Cuzzocrea S. Antiinflammatory activity of melatonin in central nervous system. Curr Neuropharmacol. 2010;8(3):228-242. doi:10.2174/157015910792246155

    [8] Souders MC, Zavodny S, Eriksen W, et al. Sleep in Children with Autism Spectrum Disorder. Curr Psychiatry Rep. 2017;19(6):34.

Brittyn Coleman, MS, RDN/LD https://www.autismdietitian.com
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