Grow Youthful: How to Slow Your Aging and Enjoy Extraordinary Health
Grow Youthful: How to Slow Your Aging and Enjoy Extraordinary Health

Melatonin

What is melatonin?

Sources of melatonin

Natural melatonin level

How to sabotage your melatonin level

Remedies / treatments using melatonin

Melatonin side effects

References

What is melatonin?

Melatonin is a naturally-occurring compound found in animals, plants and microbes. In animals it acts as both a hormone and an antioxidant.

Most melatonin is produced by the pineal gland in the brain when it is dark, and is secreted directly into the blood. Melatonin may also be produced by other cells in the body, such as bone marrow cells, lymphocytes, and epithelial cells (2,3). The melatonin in these other cells is at a higher concentration than in the blood, and it does not seem to be affected by the dark-light cycle.

In humans, 90% of melatonin is removed from the body through the liver. (4) It is not recycled.

Hormone. The daily cycle of melatonin affects the sleep-wake cycle and the circadian rhythms of several other biological functions. In many animals the amount of melatonin also varies with the length of day over the seasons, affecting seasonal functions such as reproduction, behaviour, coat growth and camouflage colouring.

Antioxidant. It can cross cell membranes and blood brain barrier. It is a potent antioxidant, able to directly absorb reactive oxygen and nitrogen species, protecting against some carcinogens. (8,10) This is melatonin's main function in plants. As an antioxidant, melatonin has an important role in the protection of nuclear and mitochondrial DNA.

Sources of melatonin

The best source of melatonin is your own brain. If you are getting sufficient protein in your diet (especially the amino acid tryptophan), and sufficient regular deep sleep, then your body will produce sufficient melatonin for good physical and mental health, and longevity.

Melatonin is found in many plants, including the herbs feverfew and St John's wort. Small quantities occur in many foods such as cherries, bananas, grapes, rice and other cereals, olive oil, wine and beer. However, eating these foods does not seem to raise melatonin plasma levels (1), probably because there is so little melatonin in them.

Supplements and products containing melatonin have been available over-the-counter in the United States since the mid-1990s. In many other countries the sale of melatonin is not permitted or requires a prescription.

Melatonin is available orally, as capsules, tablets or liquid, sublingually, or as transdermal patches.

Natural melatonin level

Infants. Infants' melatonin levels become regular in about the third month after birth, with the highest level between midnight and 08:00 (8 AM).

Young children produce their peak melatonin at night. During adolescence, melatonin production is shifted later by a couple of hours. Adolescents tend to go to sleep later, and wake later in the morning.

Older people - production falls. (5) Production of melatonin peaks earlier as people get older. This may explain why older adults go to bed earlier, wake up earlier, and have more sleep problems than children do.

How to sabotage your melatonin level

Light into the eyes at night or when sleeping inhibits melatonin production. The stronger the light intensity and length of exposure, the greater the reduction. The affect is strongest with blue light, and decreases with longer wavelengths, so that the red and infrared of firelight seems to have little effect in reducing melatonin levels at night. (6)

For optimal melatonin production, you need to sleep in a dark room. According to a study (21) just a single pulse of light during deep sleep at night causes a plunge in both the level of melatonin, and its production. Bedside lights and clocks, TV and computer screens, and lights outside the bedroom are all sufficient to sabotage your melatonin level. Here are some practical suggestions on how to optimise your light before bed, and in your bedroom.

Remedies / treatments using melatonin

Melatonin side effects

Melatonin has few side effects when healthy people take it at low doses for less than 3 months.

References

1. Coates PM, Blackman MR, Cragg GM, LevineM, Moss J, White JD. Encyclopedia of dietary supplements. 2005. New York, N.Y: Marcel Dekker. pp. 457-466. ISBN 0-8247-5504-9.

2. Maestroni GJ. The immunotherapeutic potential of melatonin. March 2001. Expert Opin Investig Drugs 10 (3): 467-76.

3. Conti A, Conconi S, Hertens E, Skwarlo-Sonta K, Markowska M, Maestroni JM. Evidence for melatonin synthesis in mouse and human bone marrow cells. May 2000. J. Pineal Res. 28 (4): 193-202.

4. Buscemi, N. et al. Melatonin for Treatment of Sleep Disorders. Summary, Evidence Report/Technology Assessment: Number 108. 2004. U.S. Department of Health & Human Services, Agency for Healthcare Research and Quality.

5. Sack RL, Lewy AJ, Erb DL, Vollmer WM, Singer CM. Human melatonin production decreases with age. 1986, J. Pineal Res. 3 (4): 379-88.

6. Kayumov L, Casper RF, Hawa RJ, Perelman B, Chung SA, Sokalsky S, Shapiro CM. Blocking low-wavelength light prevents nocturnal melatonin suppression with no adverse effect on performance during simulated shift work. May 2005, J. Clin. Endocrinol. Metab. 90 (5): 2755-61.

7. Dean W, Morgenthaler J, Fowkes SW. Smart Drugs II: The Next Generation : New Drugs and Nutrients to Improve Your Memory and Increase Your Intelligence (Smart Drug Series, V. 2). 1993. Smart Publications. ISBN 0-9627418-7-6.

8. Anisimov VN, Alimova IN, Baturin DA, Popovich IG, Zabezhinski MA, Rosenfeld SV, Manton KG, Semenchenko AV, Yashin AI. Dose-dependent effect of melatonin on life span and spontaneous tumor incidence in female SHR mice. Exp. Gerontol. April 2003, 38 (4): 449-61.

9. Oaknin-Bendahan S, Anis Y, Nir I, Zisapel N. Effects of long-term administration of melatonin and a putative antagonist on the ageing rat. March 1995, NeuroReport 6 (5): 785-8.

10. Maestroni GJ. Therapeutic potential of melatonin in immunodeficiency states, viral diseases, and cancer. 1999, Adv. Exp. Med. Biol. 467: 217-26.

11. Sharman EH, Sharman KG, Ge YW, Lahiri DK, Bondy SC. Age-related changes in murine CNS mRNA gene expression are modulated by dietary melatonin. April 2004, J. Pineal Res. 36 (3): 165-70.

12. Pohanka M. Alzheimer's disease and related neurodegenerative disorders: implication and counteracting of melatonin. 2011, Journal of Applied Biomedicine 9: 185-196.

13. Acuna-Castroviejo D, Martin M, Macias M, Escames G, Leon J, Khaldy H, Reiter RJ. Melatonin, mitochondria, and cellular bioenergetics. March 2001, J. Pineal Res. 30 (2): 65-74.

14. Larson J, Jessen RE, Uz T, Arslan AD, Kurtuncu M, Imbesi M, Manev H. Impaired hippocampal long-term potentiation in melatonin MT2 receptor-deficient mice. January 2006, Neurosci. Lett. 393 (1): 23-6.

15. Pappolla MA, Sos M, Omar RA, Bick RJ, Hickson-Bick DL, Reiter RJ, Efthimiopoulos S, Robakis NK. Melatonin prevents death of neuroblastoma cells exposed to the Alzheimer amyloid peptide. March 1997, J. Neurosci. 17 (5): 1683-90. PMID 9030627.

16. Pappolla M, Bozner P, Soto C, Shao H, Robakis NK, Zagorski M, Frangione B, Ghiso J. Inhibition of Alzheimer beta-fibrillogenesis by melatonin. March 1998, J. Biol. Chem. 273 (13): 7185-8.

17. Hurtuk A, Dome C, Holloman CH, Wolfe K, Welling DB, Dodson EE, Jacob A. Melatonin: can it stop the ringing? July 2011, Ann. Otol. Rhinol. Laryngol. 120 (7): 433-40.

18. Megwalu UC, Finnell JE, Piccirillo JF. The effects of melatonin on tinnitus and sleep. February 2006, Otolaryngol Head Neck Surg 134 (2): 210-3.

19. Rosenberg SI, Silverstein H, Rowan PT, Olds MJ. Effect of melatonin on tinnitus. March 1998, Laryngoscope 108 (3): 305-10.

20. Pirodda A, Raimondi MC, Ferri GG. Exploring the reasons why melatonin can improve tinnitus. August 2010, Med. Hypotheses 75 (2): 190-1.

21. Ben-Shlomo R, Kyriacou CP. Light pulses administered during the circadian dark phase alter expression of cell cycle associated transcripts in mouse brain. Cancer Genet Cytogenet. Feb 2010; 197(1):65-70.