Insomnia is more common in women than men by at least 50%. Although the reasons for this are complex, one important factor is hormonal fluctuations related to the menstrual cycle. These hormonal changes interact with circadian rhythms that regulate sleep and wakefulness.
Sleep challenges for females may start at menarche. In a random sample of 1,014 adolescents aged 13 to 16 years, the onset of menses was associated with a 2.75-fold increased risk for insomnia in girls due to hormonal changes in contrast to boys.
Estrogen, progesterone, and other reproductive hormones not only impact the menstrual cycle, but they also influence sleep and circadian rhythms. These 24-hour cycles of the body are regulated by our body’s master circadian clock, which is the suprachiasmatic nucleus (SCN) located in the hypothalamus of the brain.
Neurons in the SCN contain receptors for reproductive hormones, including estrogen and progesterone. As a result, these hormones can directly influence sleep and circadian rhythms. Due to hormonal fluctuations throughout the menstrual cycle and this interaction with the SCN, women may struggle with their sleep more during certain times of their monthly cycle.
Interplay of the Menstrual Cycle, Circadian Rhythms, and Sleep
A woman’s menstrual cycle is divided into the follicular phase (before ovulation) and the luteal phase (after ovulation). Healthy women commonly experience sleep complaints during the late luteal phase of the menstrual cycle, as well as the premenstrual timeframe. This may be explained, in part, by increases in progesterone during the luteal phase.
When progesterone increases, a woman’s core body temperature also increases at night. This can work against restful sleep. On the other hand, a drop in core body temperature and dissipation of heat facilitates sleep.
Furthermore, lower body temperature may promote rapid eye movement (REM) sleep. This stage of sleep is characterized by dreaming and may play a role in memory, learning, and mood. A study of healthy women found significantly decreased REM sleep during the middle of the luteal phase compared with the middle of the follicular phase of the menstrual cycle.
Sleep-related complaints are especially common in women with difficult menstrual cycles. Women with premenstrual syndrome and premenstrual dysphoric disorder commonly report insomnia, frequent awakening during sleep, bad dreams, and overall poor sleep. The most significant complaints tend to surface during the late luteal phase of the menstrual cycle.
Other Reproductive Cycle Factors in Poor Sleep
In addition to the increased tendency for sleep problems during certain stages of normal menstrual cycles, other facets of a woman’s reproductive health can also negatively impact sleep. These include:
Irregular cycles — Menstrual cycles generally lasting anywhere from 25 to 35 days, with 28 days being the average. Women with irregular cycles report more sleep difficulties than women with regular cycles, even when controlling for other factors, such as age and dysmenorrhea.
Pregnancy — Between 14% and 27% of women report sleep problems during pregnancy. One factor is the increased progesterone levels during pregnancy. Women who are pregnant commonly experience restless leg syndrome (RLS), which causes uncomfortable sensations in the legs at night. Between 15% and 25% of pregnant women in Western nations report symptoms of RLS.
Menopause — Women’s sleep challenges don’t end when their menstrual cycles cease. Instead, difficulty with sleep may increase at the menopausal stage of a woman’s life. In fact, insomnia is one of the most common health complaints of perimenopausal women. Not only does estrogen and progesterone decrease during menopause, but so does melatonin. A significant decline in these hormones may impair sleep.
Nutritional Interventions to Support Sleep
It goes without saying that good sleep habits, such as a “wind-down” routine and minimizing blue light exposure from electronic devices at night, are essential to support adequate, restful sleep. Unfortunately, for some individuals, this may not be enough. Nutritional aspects should also be considered.
Melatonin is one of the most popular natural sleep aids. In fact, it’s even used at some hospitals to support sleep. Melatonin may aid normal circadian rhythms when this supplement is taken shortly before bedtime. Melatonin may be combined with other nutrients that support sleep and healthy nervous system function, such as gamma-aminobutyric acid, inositol, and L-theanine.
Nutritional deficiencies may need to be addressed in patients with RLS. Scientists have found that magnesium and zinc deficiencies may play a role in RLS symptoms. Iron, folate, and vitamin B12 deficiencies may also play a role in RLS during pregnancy. Awareness of these potential deficiencies may help support the nutritional improvement of patients to achieve restful and adequate sleep.
By Marsha McCulloch, MS, RDN, LN