How much does your phone’s blue light really delay your sleep? Relax, it’s just 2.7 minutes
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It’s one of the most pervasive messages about technology and sleep. We’re told bright, blue light from screens prevents us falling asleep easily. We’re told to avoid scrolling on our phones before bedtime or while in bed. We’re sold glasses to help filter out blue light. We put our phones on “night mode” to minimise exposure to blue light.
But what does the science actually tell us about the impact of bright, blue light and sleep? When our group of sleep experts from Sweden, Australia and Israel compared scientific studies that directly tested this, we found the overall impact was close to meaningless. Sleep was disrupted, on average, by less than three minutes.
We showed the message that blue light from screens stops you from falling asleep is essentially a myth, albeit a very convincing one.
Instead, we found a more nuanced picture about technology and sleep.
What we did
We gathered evidence from 73 independent studies with a total of 113,370 participants of all ages examining various factors that connect technology use and sleep.
We did indeed find a link between technology use and sleep, but not necessarily what you’d think.
We found that sometimes technology use can lead to poor sleep and sometimes poor sleep can lead to more technology use. In other words, the relationship between technology and sleep is complex and can go both ways.
How is technology supposed to harm sleep?
Technology is proposed to harm our sleep in a number of ways. But here’s what we found when we looked at the evidence:
- bright screen light – across 11 experimental studies, people who used a bright screen emitting blue light before bedtime fell asleep an average of only 2.7 minutes later. In some studies, people slept better after using a bright screen. When we were invited to write about this evidence further, we showed there is still no meaningful impact of bright screen light on other sleep characteristics including the total amount or quality of sleep
- arousal is a measure of whether people become more alert depending on what they’re doing on their device. Across seven studies, people who engaged in more alerting or “exciting” content (for example, video games) lost an average of only about 3.5 minutes of sleep compared to those who engaged in something less exciting (for example, TV). This tells us the content of technology alone doesn’t affect sleep as much as we think
- we found sleep disruption at night (for example, being awoken by text messages) and sleep displacement (using technology past the time that we could be sleeping) can lead to sleep loss. So while technology use was linked to less sleep in these instances, this was unrelated to being exposed to bright, blue light from screens before bedtime.
Which factors encourage more technology use?
Research we reviewed suggests people tend to use more technology at bedtime for two main reasons:
- to “fill the time” when they’re not yet sleepy. This is common for teenagers, who have a biological shift in their sleep patterns that leads to later sleep times, independent of technology use.
- to calm down negative emotions and thoughts at bedtime, for apparent stress reduction and to provide comfort.
There are also a few things that might make people more vulnerable to using technology late into the night and losing sleep.
We found people who are risk-takers or who lose track of time easily may turn off devices later and sacrifice sleep. Fear of missing out and social pressures can also encourage young people in particular to stay up later on technology.
What helps us use technology sensibly?
Last of all, we looked at protective factors, ones that can help people use technology more sensibly before bed.
The two main things we found that helped were self-control, which helps resist the short-term rewards of clicking and scrolling, and having a parent or loved one to help set bedtimes.
Why do we blame blue light?
The blue light theory involves melatonin, a hormone that regulates sleep. During the day, we are exposed to bright, natural light that contains a high amount of blue light. This bright, blue light activates certain cells at the back of our eyes, which send signals to our brain that it’s time to be alert. But as light decreases at night, our brain starts to produce melatonin, making us feel sleepy.
It’s logical to think that artificial light from devices could interfere with the production of melatonin and so affect our sleep. But studies show it would require light levels of about 1,000-2,000 lux (a measure of the intensity of light) to have a significant impact.
Device screens emit only about 80-100 lux. At the other end of the scale, natural sunlight on a sunny day provides about 100,000 lux.
What’s the take-home message?
We know that bright light does affect sleep and alertness. However our research indicates the light from devices such as smartphones and laptops is nowhere near bright or blue enough to disrupt sleep.
There are many factors that can affect sleep, and bright, blue screen light likely isn’t one of them.
The take-home message is to understand your own sleep needs and how technology affects you. Maybe reading an e-book or scrolling on socials is fine for you, or maybe you’re too often putting the phone down way too late. Listen to your body and when you feel sleepy, turn off your device.
Chelsea Reynolds, Casual Academic/Clinical Educator and Clinical Psychologist, College of Education, Psychology and Social Work, Flinders University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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The Autoimmune Cure – by Dr. Sara Gottfried
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We’ve featured Dr. Gottfried before, as well as another of her books (“Younger”), and this one’s a little different, and on the one hand very specific, while on the other hand affecting a lot of people.
You may be thinking, upon reading the subtitle, “this sounds like Dr. Gabor Maté’s ideas” (per: “When The Body Says No”), and 1) you’d be right, and 2) Dr. Gottfried does credit him in the introduction and refers back to his work periodically later.
What she adds to this, and what makes this book a worthwhile read in addition to Dr. Maté’s, is looking clinically at the interactions of the immune system and nervous system, but also the endocrine system (Dr. Gottfried’s specialty) and the gut.
Another thing she adds is more of a focus on what she writes about as “little-t trauma”, which is the kind of smaller, yet often cumulative, traumas that often eventually add up over time to present as C-PTSD.
While “stress increases inflammation” is not a novel idea, Dr. Gottfried takes it further, and looks at a wealth of clinical evidence to demonstrate the series of events that, if oversimplified, seem unbelievable, such as “you had a bad relationship and now you have lupus”—showing evidence for each step in the snowballing process.
The style is a bit more clinical than most pop-science, but still written to be accessible to laypersons. This means that for most of us, it might not be the quickest read, but it will be an informative and enlightening one.
In terms of practical use (and living up to its subtitle promise of “cure”), this book does also cover all sorts of potential remedial approaches, from the obvious (diet, sleep, supplements, meditation, etc) to the less obvious (ketamine, psilocybin, MDMA, etc), covering the evidence so far as well as the pros and cons.
Bottom line: if you have or suspect you may have an autoimmune problem, and/or would just like to nip the risk of such in the bud (especially bearing in mind that the same things cause neuroinflammation and thus, putatively, depression and dementia too), then this is one for you.
Click here to check out the Autoimmune Cure, and take care of your body and mind!
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Ideal Blood Pressure Numbers Explained
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It’s Q&A Day at 10almonds!
Have a question or a request? You can always hit “reply” to any of our emails, or use the feedback widget at the bottom!
In cases where we’ve already covered something, we might link to what we wrote before, but will always be happy to revisit any of our topics again in the future too—there’s always more to say!
As ever: if the question/request can be answered briefly, we’ll do it here in our Q&A Thursday edition. If not, we’ll make a main feature of it shortly afterwards!
So, no question/request too big or small
❝Maybe I missed it but the study on blood pressure did it say what the 2 numbers should read ideally?❞
We linked it at the top of the article rather than including it inline, as we were short on space (and there was a chart rather than a “these two numbers” quick answer), but we have a little more space today, so:
Category Systolic (mm Hg) Diastolic (mm Hg) Normal < 120 AND < 80 Elevated 120 – 129 AND < 80 Stage 1 – High Blood Pressure 130 – 139 OR 80 – 89 Stage 2 – High Blood Pressure 140 or higher OR 90 or higher Hypertensive Crisis Above 180 AND/OR Above 120 To oversimplify for a “these two numbers” answer, under 120/80 is generally considered good, unless it is under 90/60, in which case that becomes hypotension.
Hypotension, the blood pressure being too low, means your organs may not get enough oxygen and if they don’t, they will start shutting down.
To give you an idea how serious this, this is the closed-circuit equivalent of the hypovolemic shock that occurs when someone is bleeding out onto the floor. Technically, bleeding to death also results in low blood pressure, of course, hence the similarity.
So: just a little under 120/80 is great.
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Artichoke vs Asparagus – Which is Healthier?
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Our Verdict
When comparing artichoke to asparagus, we picked the artichoke.
Why?
Both are great and it was close!
In terms of macros, artichoke has a little more protein and around 3x the carbs and fiber: the ratio there means that both vegetables have an identical glycemic index, so we’ll go with the “most food per food” reckoning of nutritional density, and call it for the artichoke.
When it comes to vitamins, artichoke has more of vitamins B3, B5, B6, B7, B9, C, and choline, while asparagus has more of vitamins A, B1, B2, E, and K. Both very respectable nutritional sets, but artichoke gets a marginal 6:5 win on strength of numbers.
In the category of minerals, artichoke has more calcium, copper, magnesium, manganese, phosphorus, and potassium, while asparagus has more iron, selenium, and zinc. A clearer 6:3 win for artichoke this time.
Once again, both of these are great foods, so by all means enjoy either or both. But if you’re looking for the nutritionally densest option, it’s the artichoke!
Want to learn more?
You might like to read:
What’s Your Plant Diversity Score?
Take care!
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The Gym For Your Mental Health
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Getting The Most Out Of Therapy
If you’ve never had therapy, what image do you have of it? Perhaps you imagine a bearded and bespectacled man in a suit, impassively making notes on a clipboard. Perhaps you imagine an empathetic woman, with tissues and camomile tea on standby.
The reality is: the experience of therapy can vary, a lot.
In its results, too! Sometimes we may try therapy and think “well that was a waste of time and money”. Sometimes we may try therapy and it’ll change our life.
So… Is there any way to make it less of a lottery?
First: knowledge is power
And while the therapist-client relationship certainly shouldn’t be a power struggle, you do want to be empowered.
So, read about different styles of therapy, and also, read some how-to guides for self-therapy. We’ve recommended some before in previous editions of 10almonds; you can check those books out here:
- How to Be Your Own Therapist: Boost your mood and reduce your anxiety in 10 minutes a day – by Owen O’Kane
- You Are the One You’ve Been Waiting For: Applying Internal Family Systems to Intimate Relationships – by Dr. Richard Schwartz
- DBT Made Simple: A Step-by-Step Guide to Dialectical Behavior Therapy – by Sheri van Dijk
- How to Do the Work: Recognize Your Patterns, Heal from Your Past, and Create Your Self – by Dr. Nicole LaPera
This will serve two purposes:
- You’ll know what to expect out of a therapist
- You can more efficiently “get to work” in therapy
It also, of course, could help you already, without even going to therapy!
Second: begin with the end in mind
A person who does not know what they want to get out of therapy, will likely not get much out of therapy. Or rather, their first task will be to figure that out. So, figure it out in advance, if you can.
Maybe you have a problem that has a specific name, for example poor self-esteem, anxiety, stress, depression, trauma, neuroticism, phobia, etc.
This isn’t Alcoholics Anonymous, and in this case you don’t want a lifetime of “Hello, my name is ______ and I have ______”, if you can help it.
So, what do you want?
- Maybe you want to be able to go to social events without feeling anxious
- Maybe you want your relationship(s) to be more secure and fulfilling
- Maybe you want to no longer have nightmares about that traumatic thing
- Maybe you want to be able to greet each day’s tasks with confidence and without overwhelm
…etc.
A good therapist will help you to set such goals (if you haven’t already), and attain them.
If you’re going the self-therapy route, then this is your job now!
It will probably start with the question: imagine that everything currently troubling you is now healed.
What would that look like, to you?
Third: get a good match for you
Unless you are going entirely the self-therapy route (which can work for some), you will want a therapist who’s a good match for you.
It may take a degree of “suck it and see” trial runs before you find the right one, but that takes time and money, so you’ll want to streamline the process as much as you can. If you do this well, you may be able to find a good therapist for you first time.
For this, personal recommendations (such as from friends) may help more than exmaining academic and institutional affiliations.
Yes, you want a well-qualified therapist who is a member in good standing of a respectable regulated body… but whether your therapist is easy for you to “get on with” will matter at least as much as whether their approach is psychodynamic, or 4th wave CBT, or IFS, or whatever seems popular in your time and place.
Bear in mind:
- Some therapists are specialized in helping with some kinds of things and not others. It will obviously help if the therapist you choose is specialized in the thing you are seeking help for.
- Some therapists may be able to relate to you better (or not), based on simple factors of who they are. To this end, while your therapist certainly doesn’t have to be a mirror image of you, factors like age, gender, race, etc can be relevant and may be worth considering, depending on what you are seeking help with, and what factors impact that thing.
Prefer keeping things to yourself?
Therapy isn’t for everyone, but having a good relationship with oneself definitely is. You might want to invest in one of the books whose reviews we linked above, and you might also get value from previous Psychology Sunday articles, which you can find in our archive (every seventh edition here has a Psychology Sunday main feature):
Click Here To Check Out The 10almonds Archive
To borrow the catchphrase of Dr. Kirk Honda (a therapist and therapy educator with decades of experience):
❝Take care of yourself, because you deserve it; you really, really do.❞
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Does Music Really Benefit The Brain?
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It’s Q&A Day at 10almonds!
Have a question or a request? We love to hear from you!
In cases where we’ve already covered something, we might link to what we wrote before, but will always be happy to revisit any of our topics again in the future too—there’s always more to say!
As ever: if the question/request can be answered briefly, we’ll do it here in our Q&A Thursday edition. If not, we’ll make a main feature of it shortly afterwards!
So, no question/request too big or small 😎
❝Is it actually beneficial for the brain to listen to music, or is it just in line with any relaxing activity? And what kind of music is most beneficial❞
The short answer, first of all, is that it is indeed beneficial.
One reason for this without having to get very deep into it, is that a very important thing for general brain health is using it, and that means lighting up all areas of your brain.
Now, we all lead different lives and thus different parts of our brains will get relatively more resources than others depending on what we do with them, and that’s ok.
For example, if you were to scan this writer’s polyglot brain, you’d surely find overdevelopment in areas associated with language use and verbal memory, but if you were to scan a taxi-driver’s brain, then it’d be spatial reasoning and spatial memory that’s overpowered, and for a visual artist, it may be visual processing and creativity that’s enhanced. A musician’s brain? Fine motor skills, auditory processing, auditory memory.
Now, for those of us who aren’t musicians, how then can we light up areas associated with music? By listening to music, of course. It won’t give us the fine motor skills of a concert violinist, but the other areas we mentioned will get a boost.
See also: How To Engage Your Whole Brain ← this covers music too, but it’s about (as the title suggests) the whole brain, so check it out and see if there are any areas you’ve been neglecting!
There are other benefits too, though, including engaging our parasympathetic nervous system, which is good for our heart, gut, brain, and general health—especially if we sing or hum along to the music:
The Science Of Sounds ← this also covers the science (yes, science) of mantra meditation vs music
As for “and what kind of music is most beneficial”, we’d hypothesize that a variety is best, just like with food!
However, there are some considerations to bear in mind, with science to support them. For example…
About tempo:
❝EEG analysis revealed significant changes in brainwave signals across different frequency bands under different tempi.
For instance, slow tempo induced higher Theta and Alpha power in the frontal region, while fast tempo increased Beta and Gamma band power.
Moreover, fast tempo enhanced the average connectivity strength in the frontal, temporal, and occipital regions, and increased phase synchrony value (PLV) between the frontal and parietal regions.❞
Read in full: Music tempo modulates emotional states as revealed through EEG insights
And if you’re wondering about those different brainwave bands, check out:
- How to get many benefits of sleep, while awake! Non-Sleep Deep Rest: A Neurobiologist’s Take ← although it’s not in the title, this does also cover the different brain wave bands
- Alpha, beta, theta: what are brain states and brain waves? And can we control them?
Additionally, if you just want science-backed relaxation, the following 8-minute soundscape was developed by sound technicians working with a team of psychologists and neurologists.
It’s been clinically tested, and found to have a much more relaxing effect (in objective measures of lowering heart rate and lowering cortisol levels, as well as in subjective self-reports) than merely “relaxing music”.
Try it and see for yourself:
Click Here If The Embedded Video Doesn’t Load Automatically!
For much deeper dive into the effect of music on the brain, check out this book we reviewed a while back, by an accomplished musician and neuroscientist (that’s one person, who is both things):
This Is Your Brain on Music – by Dr. Daniel Levitin
Enjoy!
And now for a bonus item…
A s a bit of reader feedback prompted some interesting thoughts:
❝You erred on the which is better section. Read this carefully :Looking at minerals, grapes have more calcium, copper, iron, magnesium, phosphorus, selenium, and zinc, while grapes have more potassium and manganese. A clear win for strawberries here.❞
You’re quite right; thank you for pointing it out, and kindly pardon the typo, which has now been corrected!
The reason for the mistake was because when I (writer responsible for it here, hi) was writing this, I had the information for both fruits in front of me, but the information for grapes was on the right in my field of vision, so I errantly put it on the right on the page, too, while also accidentally crediting strawberries’ minerals to grapes, since strawberries’ data was on the left in my field a vision.
The reason for explaining this: it’s a quirky, very human way to err, in an era when a lot of web content is AI-generated with very different kinds of mistakes (usually because AI is very bad at checking sources, so will confidently state something as true despite the fact that the source was The Onion, or Clickhole, or someone’s facetiously joking answer on Quora, for example).
All in all, while we try to not make typos, we’d rather such human errors than doing like an AI and confidently telling you that Amanita phalloides mushrooms are a rich source of magnesium, and also delicious (they are, reportedly, but they are also the most deadly mushroom on the face of the Earth, also known as the Death Cap mushroom).
In any case, here’s the corrected version of the grapes vs strawberries showdown:
Grapes vs Strawberries – Which is Healthier?
Enjoy!
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Hypertension: Factors Far More Relevant Than Salt
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Hypertension: Factors Far More Relevant Than Salt
Firstly, what is high blood pressure vs normal, and what do those blood pressure readings mean?
Rather than take up undue space here, we’ll just quickly link to…
Blood Pressure Readings Explained (With A Colorful Chart)
More details of specifics, at:
Hypotension | Normal | Elevated | Stage 1 | Stage 2 | Danger zone
Keeping Blood Pressure Down
As with most health-related things (and in fact, much of life in general), prevention is better than cure.
People usually know “limit salt” and “manage stress”, but there’s a lot more to it!
Salt isn’t as big a factor as you probably think
That doesn’t mean go crazy on the salt, as it can cause a lot of other problems, including organ failure. But it does mean that you can’t skip the salt and assume your blood pressure will take care of itself.
This paper, for example, considers “high” sodium consumption to be more than 5g per day, and urinary excretion under 3g per day is considered to represent a low sodium dietary intake:
Sodium Intake and Hypertension
Meanwhile, health organizations often recommend to keep sodium intake to under 2g or under 1.5g
Top tip: if you replace your table salt with “reduced sodium” salt, this is usually sodium chloride (regular table salt) cut with potassium chloride, which is almost as “salty” tastewise, but obviously contains less sodium. Not only that, but potassium actually helps the body eliminate sodium, too.
The rest of what you eat is important too
The Mediterranean Diet is as great for this as it is for most health conditions.
If you sometimes see the DASH diet mentioned, that stands for “Dietary Approaches to Stop Hypertension”, and is basically the Mediterranean Diet with a few tweaks.
What are the tweaks?
- Beans went down a bit in priority
- Red meat got removed entirely instead of “limit to a tiny amount”
- Olive oil was deprioritized, and/but vegetable oil is at the bottom of the list (i.e., use sparingly)
You can check out the details here, with an overview and examples:
DASH Eating Plan—Description, Charts, and Recipes
Don’t drink or smoke
And no, a glass of red a day will not help your heart. Alcohol does make us feel relaxed, but that is because of what it does to our brain, not what it does to our heart.
In reality, even a single drink will increase blood pressure. Yes, really:
And smoking? It’s so bad that even second-hand smoke increases blood pressure:
Get those Zs in
Sleep is a commonly underestimated/forgotten part of health, precisely because in a way, we’re not there for it when it happens. We sleep through it! But it is important, including to protect against hypertension:
Short- and long-term health consequences of sleep disruption
Move your body!
Moving your body often is far more important for your heart than running marathons or bench-pressing your spouse.
Those 150 minutes “moderate exercise” (e.g. walking) per week are important, and can be for example:
- 22 minutes per day, 7 days per week
- 25 minutes per day, 6 days per week
- 30 minutes per day, 5 days per week
- 75 minutes per day, 2 days per week
If you’d like to know more about the science and evidence for this, as well as practical suggestions, you can download the complete second edition of the Physical Activity Guidelines for Americans here (it’s free, and no sign-up required!)
If you prefer a bite-size summary, then here’s their own:
Top 10 Things to Know About the Second Edition of the Physical Activity Guidelines for Americans
PS: Want a blood pressure monitor? We don’t sell them (or anything else), but for your convenience, here’s a good one you might want to consider.
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