THE HORMONE OF DARKNESS

Melatonin has been referred to as the “hormone of darkness” owing to its peak production daily once darkness seeps in through our retina (1). Production of this hormone declines when we age, starting at around age 20 and insignificant amounts are present in those older than 60.  

Modern society conveniences also reduce the production of melatonin, namely, increased artificial (specifically, blue spectrum) light in the evening/night, changing of time zones and jet lag, shift work of any kind (defined as more than a 3-hour sleep disruption from 10pm-5am), or any circadian disruption due to chronic illness or other event. Additionally, the gut microbiota is intimately involved in melatonin production and any inflammatory state affecting this population will also decrease melatonin production and ultimately affect sleep and wakefulness. 

Melatonin Production and Sources 

Melatonin is made within most tissues, however, there is an increased concentration in the gastrointestinal tract.  Therefore, melatonin production is stimulated by the digestive process, as well as the foods that we eat.  

It appears that melatonin in plant sources is more widespread and direct versus animal sources of the protein tryptophan that require conversion to melatonin via the serotonin pathway. Common plant sources include: 

• Vegetables such as asparagus, cabbage, carrots, corn, and spinach 
• Fruits such as apples, bananas, tart and sweet cherries, grapes, kiwi, strawberries, and cucumbers 
• Nuts such as almonds, pistachios, and walnuts 
• Grains such as oats, rice and wheat 
• Beans such as soybeans 
• Seeds such as poppy, sunflower, and fennel 
• Beverages such as coffee, wine, grape juice, and orange juice. 

As indicated above, gut bacteria are vital to ensuring appropriate melatonin production. By increasing fiber and phytonutrient intake, through the foods described, we can impact both inflammation and circadian cycles, leading to not only better sleep, but better overall health. 

The key to optimizing melatonin production requires a desire to establish an appropriate environment for its production. To allow the body to do so, the following steps should be followed: 

• Work on decreasing inflammation in the body, globally. This would include consuming foods such as fish, nuts, fruits, vegetables, and adequate lean protein. Additionally, managing stress and the response to it is vital for decreasing the inflammatory load. Exercise ultimately produces an anti-inflammatory effect, so incorporating the recommended 150 minutes per week is also advised. 
• Ensure total darkness when sleeping. Due to a child’s ability to produce melatonin, a cracked door or a night light may not affect them as much as an adult; however, the aging process reduces the ability to tolerate anything more than 5 LUX (twilight is about 10 LUX), so depending on the environment, blackout shades/curtains or an eye mask may be in order. 
• Reduce blue light from electronics and LED bulbs at least two hours before bed. Dimming features on light switches can help manage this, as can blue-blocking glasses if screen time is a must. This guidance becomes more pronounced as age increases. 

While melatonin supplementation is available, it may not work for everyone and can interact with blood thinners, SSRIs (for depression), sedatives, anti-hypertensives, and anti-convulsants (1). 

If you are struggling with sleep, our nutritionist is available to help guide any dietary and lifestyle changes that can help to restore balance. Make an appointment today!