How do sleep hormones affect my body?

We’re living in a sleep-deficit epidemic and it’s having a major impact on our health. This lack of sleep isn’t just due to modern life’s need to keep us awake replying to emails, interacting on social media or watching TV. In fact, many of us have trouble falling asleep, or staying asleep once we do. And while there are many things that can cause this, one place we often forget to look for an answer is our hormones.

Many of us go about our everyday lives without giving our hormones much thought, unless you’re a woman experiencing hormonal imbalances, or a man speaking to a doctor about why you suddenly have belly fat or a sudden lack of motivation or sex drive, for example. But no matter your age or gender, hormones are hard at work in your body every day, and control so much of your life.

The research on hormones is fascinating, with new science emerging all the time. What we know – and continue to learn more about – is that hormones can easily be thrown out of sync. In other words, if one of our hormones is out of balance then it can cause a domino effect, throwing the others out of balance too. In my book The Balance Plan, I identify six hormones that are closely interlinked with each other. I call them my ‘sassy six’, and they can all play a role in keeping you up at night.

They are testosterone, oestrogen, progesterone, cortisol, insulin and the thyroid gland. Throw melatonin into the mix and you have a strong starting point to help decode why you’re awake all the time.

Read on to find out more about these hormones and how you can manage them…

Which hormones affect sleep?

The main sleep hormone is regulated by your body clock. Perhaps the most commonly known sleep-affecting hormone is melatonin, which is secreted by the pineal gland.

Melatonin rises to help us prepare for sleep, and tapers off when it’s time to wake. Normally, our bodies produce more melatonin at night time, so our levels tend to peak as it gets dark. These levels then start to drop when the sun rises. Our melatonin levels tend to be controlled by our inner body clock (the circadian rhythm), which works in sync with light outside.

When natural light starts fading, your optic nerves detect this and set the wheels in motion for the release of melatonin to help you feel drowsy. There is also evidence that shows blue light from our laptops and phones before bedtime negatively impacts on melatonin secretion, circadian rhythms and sleep. Melatonin is not only controlled by light, but also works like a see-saw with cortisol (aka the stress hormone). We'll be talking more about this later, but as cortisol levels increase, melatonin levels decrease and vice versa.

However, for those who struggle to sleep, there can be nutritional factors at work here, too. Melatonin is synthesised from tryptophan, an amino acid found in foods such as chicken, spinach, sesame seeds, beans, cheese and oats, so eating these foods can help.

Low levels of the sex hormone can cause sleep disturbances. Testosterone, although often referred to as a ‘male hormone’, is just as important to women as it is to men. In both, testosterone declines with age, although in women there is more of a sudden drop as you head towards the menopause.

Testosterone is needed for reproductive and sexual health, and it plays a vital role in sperm production, muscle mass and strength. A man’s levels of testosterone naturally start to fall as he ages (most men think it’s in their forties and fifties, though levels actually start to drop in their thirties), although stress can also have an impact on testosterone levels. Unfortunately, because testosterone affects so many functions, it can bring with it many changes for men – including emotional ones. Lower testosterone levels are also linked to changes in sleep patterns or insomnia; it can cause a vicious cycle as testosterone levels are at their highest during REM sleep.

If you’re not getting enough REM sleep it can impact your levels of testosterone and so the cycle continues.

A calming hormone essential for both men and women. Progesterone is assumed by many people to be primarily a female hormone, but although it is essential for pregnancies and menstrual cycles, it’s also important for healthy brain function, testosterone biosynthesis, spermatogenesis (maturation of sperm), cardiovascular health, bone health and nervous system health. It’s also the hormone that helps keep us calm, so it can help us all to relax, unwind and, therefore, sleep. Elevated stress can have an effect on optimal progesterone, too.

Women’s levels of progesterone often fluctuate more throughout the month than men’s, while levels drop during perimenopause and menopause. Because of this, many females going through menopause may struggle to relax, while women who are about to get their period may notice a change in the quality of their sleep.

Lower levels in later life can contribute to sleep issues. Though often thought of as the female hormone, oestrogen is actually found in both men and woman. In women it offers various feminine characteristics, but it’s also involved in everything from serotonin utilisation to the regulation of testosterone.

Oestrogen levels fluctuate during our lives, particularly for women, with it going in peaks and troughs each menstrual cycle and during pregnancy and postpartum. Levels also tend to take a nosedive when women reach menopause or perimenopause (this usually begins in your mid-40s).

Unfortunately, as oestrogen levels start to fall, many women experience sleep problems and even insomnia. Many women come to me for help and support when they reach the age of menopause. They may have long stretches at night where they’re wide awake, or they struggle with hot flushes and mood disturbances that keep them up. It may be easy to overlook oestrogen when it comes to sleep but at certain ages, women may well be cursing it.

However, if you keep your digestion optimal, stress levels low and eat a balanced, nourishing diet you can keep your oestrogen more balanced and experience fewer symptoms.

Elevated stress levels can impact on hormones and trigger insomnia Widely known as our stress hormone, cortisol can trigger sleep problems in many of us. With hectic modern-day lives, most of us – no matter what age or gender – will experience issues with high stress at some point. Whether you’re a teenager suffering with exam anxiety or you’re a parent chasing after little ones on no sleep or you have a high-powered job with lots of pressure, I’m sure many will relate.

Cortisol is a steroid hormone made in the adrenal glands. It’s released into the blood and levels tend to be higher first thing in the morning (this is to energise us, as its increase sets off a reduction in melatonin production), and lower at night to allow relaxation to take over. However, many of us now live busy lives with non-stop hustling and bustling.

Cortisol is often elevated in those who work shifts, while it can also be high in those who have experienced a major life event – the breakdown of a relationship or the loss of a loved one. If you’re chronically stressed, then your cortisol levels may stay sky-high throughout the day, and continue to be high into the night – elevated night-time cortisol levels can then cause sleep disturbances as melatonin is reduced, triggering insomnia.

Lack of sleep can affect this important blood sugar regulator. This handy hormone is made in the pancreas and helps stop our blood sugar levels from getting too high or too low. Unfortunately, research shows that a lack of sleep can affect our insulin levels, causing as much insulin resistance as a high-fat or high-sugar diet. Meanwhile, poorly regulated blood-sugar levels during the day can lead to blood sugar fluctuations during the night, which can disrupt your sleep. This is why diet is crucial when it comes to keeping blood sugar levels stable and our hormones balanced. See opposite for some foods that help you maintain good hormone health.

Why an overactive thyroid can stop you sleeping

An under- or over-active thyroid can lead to energy and sleep problems. The thyroid is a gland in your neck that releases hormones to stimulate different metabolic functions in your cells, influencing brain development and even hair growth. Unfortunately, it’s not perfect and many clients come to me with thyroid problems such as hypothyroidism (an under-active thyroid) and hyperthyroidism (an over-active thyroid). Both can cause sleep disturbances.

An over-active thyroid can trigger sleep problems as the nervous system can be overstimulated. In turn, this can then make it harder to fall asleep, and can also cause uncomfortable night sweats. On the flipside, lower levels of hormone production can lead to a lack of energy, causing weakness and tiredness. Although you may think that would help you sleep, unfortunately it doesn’t and hypothyroidism is linked to both insomnia and sleep disturbances. If you suspect you’re having problems with your thyroid, it’s important to go and chat things through with your GP, who may advise that you get a blood test to investigate further.

5 foods to balance your sleep hormones

Eat your way to hormonal health with these delicious menu choices.

1. Avocados – These contain healthy fat to help build happy hormones. I eat avocados most days, mashed on wholegrain toast, or added to green smoothies in the morning.
2. Leafy greens – My ultimate health food, leafy greens help the body detoxify. They are also full of iron, fibre, zinc and magnesium, which support thyroid health.
3. Protein – Lean proteins, such as those found in chicken, turkey, fish or plant-based proteins (think lentils, beans, tofu or quinoa) help to build healthy hormones. They also keep you feeling fuller for longer, meaning more balanced blood sugars.
4. Probiotic foods – A healthy gut is crucial to overall health, so I always suggest eating sources of probiotics each day. Try natural yogurt or kefir, bone broth, sourdough bread, kombucha or kimchi.
5. Flax seeds – Add ground flax seeds to morning porridge or smoothies. They’re a great source of anti-inflammatory omega-3s and phytoestrogens, which can help with all kinds of female hormonal health issues, including PMS. Flax seed can also help the body to mop up an excess of hormones and support detox.

Looking for more expert advice to improve your sleep? Find out what to eat to improve your sleep, discover if alcohol is making you sleep deprived and learn about the relaxing qualities of sleep ASMR.

You might also benefit from trying our sleep breathing exercises to help you relax at bedtime, stretching out with a sleep yoga routine or having a go at some sleep visualisation exercises. If light is keeping you awake, check out our pick of the best sleep masks to help you feel rested and refreshed.

About Angelique Panagos

Angelique is a nutritionist and author with a passion for the healing power of food. She’s on a mission to help people to live a healthier life, filled with energy and free from hormonal imbalance.

Visit Angelique's website to find out more: www.angeliquepanagos.com.

This article was first published in Sleep Well Magazine in 2019. Featured image: Pexels/Andrea Piacquadio.