Much of the answer may depend on your particular worldview when it comes to health matters in general.
Light, after all, plays a crucial role in many aspects of human health so it’s not such a stretch to consider its role in the process of ovulation and conception.
For starters, the pineal gland in the brain produces melatonin, that critical hormone that controls the 24 hour day/night cycle also known as the circadian rhythm. Melatonin production is suppressed when the retinal ganglion cells of the eye detect sunlight and produce the photoreceptor melanopsin.
Proper synchronization of the day/night cycle based on the detection of sunlight by the eyes governs the following bodily functions:
- Endocrine rhythms
- Body temperature
- Glucose homeostasis (critical for blood sugar control)
- Lipogenesis (the process of converting simple sugars to fatty acids)
- Locomotor activity
Disruption of circadian rhythm can have a profound effect on health. Nighttime shift work or exposure to light at night, for example, has been found to increase the risk of certain cancers.
How then does light affect hormone health?
According to Louise Lacey, author of the book Lunaception, ancestral women understood that the menstrual cycle was governed by the cycle and light of the moon and that our bodies have naturally adapted to respond to its light and dark rhythms.
Lacey’s research also uncovered that the sexual cycles of some primates include peaks of activity relating to the lunar cycle.
Research by Dr. John Rock MD and physicist E.M. Dewan discovered that women who suffered from irregular menstrual cycles could normalize them by alternating sleeping in complete darkness with 3 nights of light. The protocol required sleeping in complete darkness on days 1-13, sleeping with a 100-watt lightbulb turned on all night in the bedroom for days 14-17, and then sleeping again in complete darkness for the remainder of the cycle.
Lacey tried variations of Dr. Rock and Dewan’s experiments on herself and a group of over two dozen other women and found that sleeping in complete darkness punctuated by three nights of light each cycle triggered ovulation.
The light intensity that was necessary replicated the light of the full moon and could be as mild as the light from a 75-watt lightbulb beaming into the bedroom from a nearby bathroom.
Lunaception in a Modern Setting
Lacey called this process lunaception and found that it could be used to effectively direct personal fertility. Lacey and 27 of her friends developed regular, healthy menstrual cycles by implementing the principles of lunaception including successful avoidance of pregnancy in all cases until menopause.
According to Katie Singer, author of Honoring Our Cycles, “other clinical researchers have also found that sleeping in the absence of light (introducing it for a few days each cycle, or sleeping only in the absence of light) can help women in a variety of situations to strengthen their cycles”. Noted improvements included:
- Women who were not ovulating became ovulatory.
- Cycles that had been very short (26 days or less) or very long (35 days or more) normalized at between 27-31 days long
- Follicle-stimulating hormone (FSH) levels normalized
- Problems with mid-cycle spotting were significantly reduced
- Progesterone levels were strengthened
- Women with a history of miscarriage were able to sustain pregnancy.
- The intensity of premenopausal symptoms, including hot flashes, sleeplessness, and mood changes were reduced
What Exactly Does Sleeping in Darkness Mean?
Sleeping in darkness can be quite a different experience depending on whether one is in an urban or rural environment. To experience the benefits of lunaception, Katie Singer defines sleeping in darkness as follows:
- Fifteen minutes after turning out the lights, you can’t see objects in the room, including your own hands.
- Bedroom windows are covered with room-darkening blinds or curtains backed by light-blocking fabric.
- Cracks of light from under doors can be covered with a towel.
- Cracks around the edges of windows can be covered with aluminum foil.
Room darkening shades or blackout curtains (such as these that block 99.9% of light) can be purchased if the amount of outside light during the night is especially bright for those living in busy, urban settings.
How Lunaception Helps Nursing Mothers
Sleeping in complete darkness can also help support lactational amennorhea, or lack of fertility while nursing. Another method is frequent nursing all day long, including nighttime, but this can be rather exhausting particularly if baby is a good sleeper.
According to Katie Singer, author of the Garden of Fertility,
During pregnancy and while breast feeding (until menses resumes) it is best to sleep in the absence of light. If you need light in the middle of the night to nurse or use the bathroom, use as dim a light as possible. A red bulb (like those used in a photographer’s darkroom) purchased from a camera store, can be helpful.
Have you implemented the principles of lunaception in your living environment? If so, what has been your experience with regard to the effect on your hormone health and fertility?
Sarah, The Healthy Home Economist
Sources and More Information
Honoring Our Cycles, Katie Singer
Dewan, E.M. PhD, Miriam Menkin, MA, and John Rock, MD, “On the Possibility of a Perfect Rhythm of Birth Control by Periodic Light Stimulation, American Journal of Obstetrics and Gynecology 99 (1967): 1016-19
Sarah Pope has been a Health and Nutrition Educator since 2002. Her work is dedicated to helping families effectively incorporate the principles of ancestral diets within the modern household. She is a sought after lecturer around the world for conferences, summits, and podcasts.
Her work has been covered by major media including USA Today, ABC, NBC, and many others.