MELATONIN AND OTHER MARVELS

I’m just back from walking through Sicily, which has reminded me of the importance of sunlight, darkness and exercise for fantastic sleep.  After days of long and strenuous walking – up and down the Madonie mountains and their steeply-sided medieval villages – I slept like a dog/baby/log (as you prefer).  Here, in the mountains, the darkness was thick and dense, the sort of darkness you can almost touch.  The morning skies were brightly, brilliantly blue. I felt as though I had dropped into some ancient nomadic version of myself: eating, sleeping, walking – and repeating.

So imagine my surprise when, one Sicilian evening, a study appeared on my phone (this was clearly not the ancient nomadic version of myself) linking the melatonin prompted by darkness to a faster walking speed and a longer stride in people with Multiple Sclerosis.   How could this possibly be?

We tend to think of melatonin as a hormone of sleep.  But scientists are now uncovering a vastly larger remit for melatonin. In fact some sleep experts and oncologists now think that the reason breast cancer is associated with shift work is because light-at-night suppresses melatonin – and it’s the lack of melatonin that enables (breast) cancerous cells to proliferate more effectively.

Studies have also shown that melatonin may ease symptoms of irritable bowel syndrome (IBS), reduce the severity of tinnitus, lower blood sugar levels in people with type 2 diabetes, and even lead to small amounts of weight loss.  Clearly, melatonin does more than help us fall asleep. Annoyingly, production of melatonin tends to diminish as we age. Which might explain why a 2020 meta study found that melatonin was a more effective sleep aid for older people than for younger people.

A day later, a second study of melatonin dropped into my in-box.  This study – involving 1689 participants – showed that melatonin supplements were most effective for sleep when taken three hours before bed (rather than the 30 minutes usually recommended) – with 3-4 mg being the most efficacious amount.  And yes, supplementing with melatonin helped participants sleep for an average of 20 minutes more than normal (3 mg was sufficient to achieve this). They also fell asleep nine minutes faster, on average. You can read the study here.

In the UK, melatonin is only available on prescription.  But in the US, Australia and some European countries it can be bought over the counter. Indeed, in the US, sales of melatonin have spiralled: Between 2009 and 2018, use of the supplement increased fivefold, and between 2016 and 2020, sales of melatonin rose from $285 million to $821.

Both Susan and I have sporadically experimented with melatonin supplements – and we both felt that our sleep was a little more robust on the nights we popped a melatonin pill.  In case you’re wondering, melatonin is largely safe, non-addictive and without dangerous side effects (according to the ever-trustworthy Examine.com). If you’ve tried spending your days in bright light (sunlight causes the body to produce serotonin which helps activate melatonin) and your evenings in candle-light and you’re still not sleeping, ask your doctor for a melatonin prescription and see if it works. And for anyone who takes, or has taken, melatonin supplements, please do share your experiences in the Comment box.

Melatonin can also be found in food and a 2017 study concluded that ‘eating melatonin-rich foods could assist sleep.’ Indeed, studies have measured the blood serum levels of people after eating melatonin-rich foods and found significantly raised levels. During the last decades, melatonin has been identified in eggs, oily fish, mushrooms, seeds and nuts (particularly pistachios and almonds), tart cherry juice, oats and milk (particularly when cows were milked at night). This same study also found melatonin to be richly bioactive: antioxidant, anti-inflammatory, immune-boosting, anti-cancerous, cardiovascular protective, anti-diabetic, anti-obese, neuroprotective and anti-aging.  Whether synthetic melatonin (that’s the pill version) offers this is less clear.   Meanwhile, newer studies are finding that melatonin might help reduce anxiety and counter depression. All in all, melatonin appears to be a bit of a marvel.

Another sleep-related study caught my attention this week: a study of weighted blankets.  I wrote an earlier blog post on a study that found weighted blankets (these are very heavy blankets formed of glass beads or ball bearings) increased the body’s own production of melatonin. This new study (from two Australian universities) also found that weighted blankets resulted in better sleep among adults. In addition, the researchers found that sleeping beneath a weighted blanket resulted in better mood, which they attributed to the ‘snug factor’ – apparently heavy blankets give the body ‘a warm hug while sleeping’.  I always sleep under a weighted blanket when I’m at home.  It reminds me of the old-fashioned bed my grandma used to tuck me up in – tightly tucked in sheets, blankets and a heavy eiderdown.  Before the relatively recent advent of duvets we all slept like this. Sort of swaddled and tucked-in.  My own theory – based loosely on evolutionary biology – is that, for thousands of years, we slept beneath animal pelts and skins.  We evolved to sleep beneath weight and mass.  It comforts us in some way – perhaps because it makes us feel protected (if only from the elements that once meant life or death).

The Australian researchers say (very boldly) that the evidence for weighted blankets is ‘strong enough for them to be officially recommended by health professionals.’ The same researchers are currently in the last stages of a project to assess the feasibility and effectiveness of weighted blankets as a sleep intervention for people  with dementia. We’ll keep you posted. I should add that the last time I wrote about weighted blankets, one reader rushed out and bought one, only to find that it was too heavy for her to manoeuvre.  I use a single (not a double). It’s suggested that you buy a blanket weighing around 10% of your body weight.

And if neither weighted blanket nor melatonin works for you, another study published this year looked at CBD, finding that ‘CBD shows promise in improving sleep quality.’  I’ve experimented with CBD, and yes, it improved my sleep.  But brisk up-and-down walking also activates our own endocannabinoid system – which might explain why my mountain rambles resulted in a string of deeply restorative slumber-filled nights. I’ve got a chapter on this entire subject in 52 Ways to Walk for anyone interested in the mechanics of our own in-built cannabinoid system.

One further supplement made ‘sleep headlines’ last month: creatine.  I’ve written about creatine before, but only in the context of building and maintaining muscle.  This new study found that women who took creatine supplements slept better on days in which they did resistance training. An earlier study found similar results although no one is quite sure why the combination of creatine and resistance training makes for such a good night of shut-eye.  Resistance training on its own has been found to improve sleep – with some studies suggesting it does this more effectively than plain aerobic exercise.  A creatine supplement appears to further augment the sleep-inducing effects of lifting weights. I’ll be experimenting with this and will let you know how I get on.

Speaking of weights, I discovered Dr Stacy Sims this summer and promptly listened to every interview with her that I could find.  She’s a highly trained specialist in female health and a passionate advocate for women (well, everyone) doing resistance training.  She’s a refreshing voice on menopause, arguing that symptoms can often be tackled with diet, exercise and herbal remedies, rather than HRT/medication. I like this Zoe podcast if you want to hear more from Dr Sims.

Returning from bright, sunny Sicily to grey London was a bit disconcerting. But I’m determined to hang on to the marvellous sleep I experienced, so my November goal is to get outside as much as possible (two hours every day is my goal.)

We’ve been banging on about the significance of day light exposure for years (see here and here for instance). I’ve written about it in books and newspaper articles.  Light sets our biological clock, affecting our ability to concentrate, controlling our digestion, blood pressure and ability to sleep.  And now that the evenings are drawing in, and we’re embracing the restful wintry and melatonin-inducing darkness, it’s even more imperative that we make time to be outside during day light hours, preferably moving, preferably getting a little breathless, preferably lifting and carrying.   Get this right and you might not need a sleep supplement or a weighted blanket ….

But why two hours?

In September I took my son to see an eminent eye surgeon.  ‘You should be outside for two hours a day,’ the eye Prof told him. ‘It’s the light,’ he added. ‘Our eyes need lots of natural outdoor light and they’re not getting it. We should all be outside for two hours a day.’ Outdoor light contains ultraviolet, violet, infrared and red light that indoor light can’t provide. It’s thought that violet light is essential for eye health.  Sunglasses, like glass windows, also block these parts of the natural light spectrum. Go sunglass-free if you can.

So there you have it.    Wrap up warmly, get the waterproofs on if necessary, take walking poles if you need them, and head off for a wonderful winter walk. Your sleep, eyes, muscles, heart  – and just about everything else – will thank you.

Annabel

PS If you want more of my sleep tips, Sleepless: Discovering the Power of the Night Self is now out in paperback.