Category Archives: Mis-clock-ceptions

Spring Forward, Fall Back – should you watch out tomorrow morning?

If you live in (most places in) the United States as well as many other countries, you have reset your clocks back by one hour last night (or last week). How will that affect you and other people?
One possibility is that you are less likely to suffer a heart attack tomorrow morning than on any other Monday of the year. Why? Let me try to explain in as simple way as possible (hoping that oversimplification will not lead to intolerable degrees of inaccuracy).
Almost all biochemical, physiological and behavioral parameters in almost all (at least multicellular) organisms display diurnal (daily) rhythms and most of those are directly driven by the circadian clock (or, more properly, by the circadian system). Here is an old and famous chart displaying some of the peaks (acrophases) of various physiological functions in the human:
It may be a little fuzzy, but you can see that most of the peaks associated with the cardiovascular function are located in the afternoon. The acrophases you see late at night are for things like “duration of systole” and “duration of diastole” which means that the Heart Rate is slow during the night. Likewise, blood pressure is low during the night while we are asleep.
Around dawn, heart rate and blood pressure gradually rise. This is a direct result of the circadian clock driving the gradual rise in plasma epinephrine and cortisol. All four of those parameters (HR, BP, Epinephrine and Cortisol) rise roughly simultaneously at dawn and reach a mini-peak in the morning, at the time when we spontaneously wake up:
This rise prepares the body for awakening. After waking up, the heart parameters level off somewhat and then very slowly rise throughout the day until reaching their peak in the late afternoon.
Since the four curves tend to be similar and simultaneus in most cases in healthy humans, let’s make it easier and clearer to observe changes by focusing only on the Cortisol curve in the morning, with the understanding that the heart will respond to this with the simultaneous rise in heart rate and blood pressure. . This is how it looks on a day when we allow ourselves to wake up spontaneously:
But many of us do not have the luxury of waking up spontaneously every day. We use alarm clocks instead. If we set the alarm clock every day to exactly the same time (even on weekends), our circadian system will, in most cases (more likely in urban than rural areas, though), entrain to the daily Zeitgeber – the ring of the alarm-clock – with a particular phase-relationship. This usually means that the rise in cardiovascular parameters will start before the alarm, but will not quite yet reach the peak as in spontaneous awakening:
The problem is, many of us do not set the alarm clocks during the weekend. We let ourselves awake spontaneously on Saturday and Sunday, which allows our circadian clock to start drifting – slowly phase-delaying (because for most of us the freerunning period is somewhat longer than 24 hours). Thus, on Monday, when the alarm clock rings, the gradual rise of cortisol, heart rate and blood pressure will not yet be as far along as the previous week. The ring of the alarm clock will start the process of resetting of the circadian clock – but that is the long-term effect (may take a couple of days to complete, or longer.).
The short term effect is more dramatic – the ring of the alarm clock is an environmental stressor. As a result, epinephrine and cortisol (the two stress hormones) will immediately and dramatically shoot up, resulting in an instantenuous sharp rise in blood pressure and heart rate. And this sharp rise in cardiovascular parameters, if the heart is already damaged, can lead to a heart attack. This explains two facts: 1) that heart attacks happen more often on Mondays than other days of the week, and 2) that heart attacks happen more often in the morning, at the time of waking up, than at other times of day:
Now let’s see what happens tomorrow, the day after the time-change. Over the weekend, while you were sleeping in, your circadian system drifted a little, phase delaying by about 20 minutes on average (keep in mind that this is an average – there is a vast variation in the numerical value of the human freerunning circadian period). Thus, your cardiovascular parameters start rising about 20 minutes later tomorrow morning than last week. But, your alarm clock will ring an entire hour later than last week – giving you an average of a 40-minute advantage. Your heart will be better prepared for the stress of hearing the ringing than on any other Monday during the year:
Now let’s fast-forward another six month to the Spring Forward weekend some time in March or April of next year. Your circadian system delays about 20 minutes during the weekend. On top of that, your alarm clock will ring an hour earlier on that Monday than the week before. Thus, your cardiovascular system is even further behind (80 minutes) than usual. The effect of the stress of the alarm will be thus greater – the rise in BP and HR will be even faster and larger than usual. Thus, if your heart is already damaged in some way, your chances of suffering an infarct are greater on that Monday than on any other day of the year:
This is what circadian theory sugests – the greater number of heart attacks on Mondays than other days of the week (lowest during the weekend), the greatest number of heart attacks on the Monday following the Spring Forward time-change compared to other Mondays, and the lowest incidence of heart attacks on the Monday following the Fall Back time-change compared to other Mondays.
A couple of days ago, a short paper appeared that tested that theoretical prediction and found it exactly correct (Imre Janszky and Rickard Ljung, October 30, 2008, Shifts to and from Daylight Saving Time and Incidence of Myocardial Infarction, The New England Journal of Medicine, Volume 359:1966-1968, Number 18.). The authors looked at a large dataset of heart attacks in Sweden over a large period of time and saw that (if you look at the numbers) the greatest number of heart attacks happens on Mondays compared to other days of the week (and yes, the numbers are lowest during the weekend), the greatest number of heart attacks occur on the Monday following the Spring Forward time-change compared to Mondays two weeks before and after, and the lowest incidence of heart attacks happens on the Monday following the Fall Back time-change compared to Mondays two weeks before and after:
Thus, the predictions from the circadian theory were completely and clearly correct. But I was jarred by the conclusions that the authors drew from the data. They write:

The most plausible explanation for our findings is the adverse effect of sleep deprivation on cardiovascular health. According to experimental studies, this adverse effect includes the predominance of sympathetic activity and an increase in proinflammatory cytokine levels.3,4 Our data suggest that vulnerable people might benefit from avoiding sudden changes in their biologic rhythms.
It has been postulated that people in Western societies are chronically sleep deprived, since the average sleep duration decreased from 9.0 to 7.5 hours during the 20th century.4 Therefore, it is important to examine whether we can achieve beneficial effects with prolonged sleep. The finding that the possibility of additional sleep seems to be protective on the first workday after the autumn shift is intriguing. Monday is the day of the week associated with the highest risk of acute myocardial infarction, with the mental stress of starting a new workweek and the increase in activity suggested as an explanation.5 Our results raise the possibility that there is another, sleep-related component in the excess incidence of acute myocardial infarction on Monday. Sleep-diary studies suggest that bedtimes and wake-up times are usually later on weekend days than on weekdays; the earlier wake-up times on the first workday of the week and the consequent minor sleep deprivation can be hypothesized to have an adverse cardiovascular effect in some people. This effect would be less pronounced with the transition out of daylight saving time, since it allows for additional sleep. Studies are warranted to examine the possibility that a more stable weekly pattern of waking up in the morning and going to sleep at night or a somewhat later wake-up time on Monday might prevent some acute myocardial infarctions.

And in the quotes in the press release they say the same thing, so it is not a coincidence:

“It’s always been thought that it’s mainly due to an increase in stress ahead of the new working week,” says Dr Janszky. “But perhaps it’s also got something to do with the sleep disruption caused by the change in diurnal rhythm at the weekend.”

Dr.Isis has already noted this and drew the correct conclusion. She then goes on to say something that is right on the mark:

And, of course, my first thought is, what about all the other times we are sleep deprived by, you know, one hour. Is waking up in the middle of the night to feed Baby Isis potentially going to cause Dr. Isis to meet her maker early? In that case Baby Isis can freakin’ starve. But, this is the New England Journal of Medicine and Dr. Isis appreciates the innate need that authors who publish here have to include some clinical applicability in their work.

The authors responded to Dr.Isis in the comments on her blog and said, among else:

We wonder whether you have ever tried to publish a research letter somewhere. The number of citations (maximum 5!) and the number of words are strictly limited. Of course we are familiar with studies on circadian rhythms and cardiovascular physiology. There was simply no space to talk more about biological rhythms than we actually did.

But what they wrote betrays that even if they are familiar with the circadian literature, they do not really understand it. Nobody with any circadian background ever speculates about people’s conscious expectations of a stressful week as a cause of heart attacks on Monday mornings. Let me try to explain why I disagree with them on two points they raise (one of which I disagree with more strongly than the other).
1) Sleep Deprivation. It is important to clearly distinguish between the acute and the chronic sleep deprivation. Sleepiness at any given time of day is determined by two processes: a homeostatic drive that depends on the amount of sleep one had over a previous time period, and a circadian gating of sleepiness, i.e., at which time of day is one most likely to fall asleep. Sleep deprivation affects only the homeostatic drive and has nothing to do with circadian timing.
Humans, like most other animals, are tremendously flexible and resilient concerning acute sleep deprivation. Most of us had done all-nighters studying for exams, or partying all night with non ill effects – you just sleep off the sleep debt the next day or the next weekend and you are fine. Dr.Isis is not going to die because her baby wakes her up several times during the night. This is all part of a normal human ecology, and human physiology had adapted to such day-to-day variations in opportunities for sleep.
The Chronic sleep deprivation is a different animal altogether. This means that you are getting less sleep than you need day after day, week after week, month after month, year after year, with rarely or never sleeping off your sleep debt (“catching up on sleep”). As a result, your cognitive functions suffer. If you are a student, you will have difficulties understanding and retaining the material. If you are a part of the “creative class”, you will be less creative. If you are a scientist, you may be less able to clearly think through all your experiments, your data, and your conclusions. No matter what job you do, you will make more errors. You may suffer microsleep episodes while driving and die in a car wreck. Your immune system will be compromised so you will constantly have sniffles and colds, and may be more susceptible to other diseases.
And yes, a long term chronic sleep deprivation may eventually damage your heart to the extent that you are more susceptible to a heart attack. This means that you are more likely to suffer a heart attack, but has no influence on the timing of the heart attack – it is the misalignment between the natural circadian rhythms of your body and the social rhythms imposed via a very harsh stressor – the alarm clock – that determines the timing. Being sleep deprived over many years means you are more likely to have a heart attack, but cannot determine when. Losing just one hour of sleep will certainly have no effect at all.
Thus, the data presented in the paper have nothing to say about sleep deprivation.
2) Cytokines. These are small molecules involved in intercellular signaling in the immune system. Like everything else, they are synthesized in a diurnal manner. But they act slowly. Maybe they play some small part in the gradual damage of the heart in certain conditions (prolonged inflammation, for instance), thus they may, perhaps, have a role in increasing risk of a heart attack. But they play no role in timing of it. Thus they cannot be a causal factor in the data presented in the paper which are ONLY about timing, not the underlying causes. The data say nothing as to who will suffer a heart attack and why, only when you will suffer one if you do.
If I was commissioned to write a comprehensive review of sleep deprivation, I may have to force myself to wade through the frustratingly complicated and ambiguous literature on cytokines in order to write a short paragraphs under a subheading somewhere on the 27th page of the review.
If I had a severe word-limit and needed to present the data they showed in this paper, I would not waste the space by mentioning the word “cytokine” at all (frankly, that would not even cross my mind to do) as it is way down the list of potential causes of heart attack in general and has nothing to do with the timing of heart attacks at all, thus irrelevant to this paper.
So, it is nice they did the study. It confirms and puts clear numbers on what “everybody already knew for decades” in the circadian community. But their interpretation of the data was incorrect. This was a purely chronobiological study, yet they chose to present it as a part of their own pet project instead and tried mightily to make some kind of a connection to their favourite molecules, the cytokines, although nothing warranted that connection. Nails: meet hammer.
The fake-insulted, haughty and inappropriate way/tone they responded to Dr.Isis is something that is important to me professionally, as is there misunderstanding of both the role and the tone of science blogs, so I will revisit that issue in a separate post later. I promise. It is important.
But back to Daylight Saving Time. First, let me ask you (again) to see Larry’s post from last year, where you will find a lot of useful information and links about it. What is important to keep in mind is that DST itself is not the problem – it is the time-changes twice a year that are really troubling.
Another important thing to keep in mind is that DST was instituted in the past at the time when the world looked very different. At the time when a tiny sliver of the population is still involved in (quite automated and mechanized) agriculture, when electricity is used much more for other things than illumination (not to mention that even the simple incandescent light bulbs today are much more energy efficient than they used to be in the past, not to mention all the newfangled super-efficient light-bulbs available today), when many more people are working second and third shifts than before, when many more people work according to their own schedules – the whole idea of DST makes no sense any more.
Even if initially DST saved the economy some energy (and that is questionable), it certainly does not do so any more. And the social cost of traffic accidents and heart attacks is now much greater than any energy savings that theoretically we may save.
Furthermore, it now seems that circadian clocks are harder to shift than we thought in the past. Even that one-hour change may take some weeks to adjust to, as it is not just a singular clock but a system – the main pacemaker in the SCN may shift in a couple of days, but the entire system will be un-synchronized for some time as it may take several weeks for the peripheral clocks in the liver and intestine to catch up – leading to greater potential for other disorders, e.g., stomach ulcers.
The social clues (including the alarm clocks) may not be as good entraining agents as we thought before either, especially in rural areas where the natural lighting still has a profound effect.
Finally, the two time-change days of the year hit especially hard people with Bipolar Disorder and with Seasonal Affective Disorder – not such a small minority put together, and certainly not worth whatever positives one may find in the concept of DST. We should pick one time and stick with it. It is the shifts that cost the society much more than any potential benefits of DST.
Related reading:
Daylight Saving Time
Daylight Savings Time worse than previously thought
Sun Time is the Real Time
Seasonal Affective Disorder – The Basics
Lesson of the Day: Circadian Clocks are HARD to shift!
Lithium, Circadian Clocks and Bipolar Disorder
Everything You Always Wanted To Know About Sleep (But Were Too Afraid To Ask)

Circadian Quackery

Circadian QuackeryBelieve me, I love the word “circadian”. It is a really cool word, invented by Franz Halberg in the late 1950s, out of ‘circa’ (Latin – “about”) and diem (“a day”), to denote daily rhythms in biochemistry, physiology and behavior generated by the internal, endogenous biological clocks within living organisms.
It’s been a while since the last time I found someone mistaking the word for ‘cicada’ which is a really cool insect. ‘Circadian’ has become quite common term in the media and, these days increasingly, in popular culture. Names of some bands contain the word. A few blogs’ names contain the word. I guess the word has cool modern scientific connotations, sounds like something from Star Trek, and on top of it has the ever-alluring association to the shape of the circle and the endless cycle of Time. Thus, it has the New-Agey air of a mix of scientific and mystical to it.
That does not mean that people know what the word means. I’ve seen quite a lot of confusion about the meaning of it on blogs and elsewhere. It was just a matter of time until the word was misappropriated by quacks. And yes, it has happened. I have recently found two examples of medical quackery with the word “circadian” prominently displayed. Let me show you why both are utterly wrong and what is the commonality between the two: [under the fold]

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For my European Readers

Not that it’s a good thing….

Reverend William Paley’s Circadian Clock

Reverend William Paley's Circadian ClockAn oldie but goodie (June 12, 2005) debunking one of the rare Creationist claims that encroaches onto my territory.

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Sleep Genes are not the same as ‘Genes for sleep’

Back in the late 1990s, when people first started using various differential screens, etc. looking for elusive “genes for sleep”, I wrote in my written prelims (and reprinted it on my blog several years later):

Now the sleep researchers are jumping on the bandwagon of molecular techniques. They are screening for differences in gene expression between sleeping and awake humans (or rats or mice), searching quite openly for the “genes for sleep”. Every time they “fish out” a gene, it turns out to be Protein kinase A, a dopamine receptor, or something similar with a general function in the brain. Don’t they understand that sleep (like hibernation) is an emergent property of a multicellular brain? Unlike in the clock field, a single neuron does not carry the function – it does not sleep. Only whole (or halves of) brains can be asleep or awake. The sleep “mechanism” is not a molecular mechanism but a result of a particular pattern of neural connectivity and activity.

And, lo an behold, all the genes that affect sleep (the duration or quality of it, not timing which is guided by the circadian clock), turned out to be those “maintanance” molecules, involved in general, day-to-day activity of neurons. Most geneticists have since moved away from such a simplistic, bean-bag genetics notion of sleep and started studying sleep from a much more integrative perspective. But some persist. The newest discovery of a “sleep-gene” is just like what I predicted, a general-maintanance molecule – an ion channel:
Second Sleep Gene Identified:

A gene that controls the flow of potassium into cells is required to maintain normal sleep in fruit flies, according to researchers at the University of Wisconsin School of Medicine and Public Health (SMPH). Hyperkinetic (Hk) is the second gene identified by the SMPH group to have a profound effect on sleep in flies.
The finding supports growing evidence that potassium channels–found in humans and fruit flies alike–play a critical role in generating sleep.
“Without potassium channels, you don’t get slow waves, the oscillations shown by groups of neurons across the brain that are the hallmark of deep sleep,” says Chiara Cirelli, SMPH psychiatry professor and senior author on the latest study, which appeared in the May 16, 2007, Journal of Neuroscience.

Very cool and important for the advancement of our understanding of sleep, but surely not a “gene for sleep”.

Circadian Meditation?!

How does one fisk a medical quackery when there is no attempt whatsoever to explain what it is all about – not even a string of New-Age mumbo-jumbo, nonsensical, vaguely English-sounding words. All it says is: Buy The Book. Yeah, right…
Related: Circadian Quackery

Lesson of the Day: Circadian Clocks are HARD to shift!

This is a story about two mindsets – one scientific, one not – both concerned with the same idea but doing something very different with it. Interestingly, both arrived in my e-mail inbox on the same day, but this post had to wait until I got out of bed and started feeling a little bit better.
First, just a little bit of background:

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Circadian Rhythm Degeneration Syndrome?

OK, it is a premise of a new SF novel. The book description does not look too promising, though I guess I should read it for professional reasons (I put it on my amazon wish-list for now):
Last call from Earth -Stage I, Biological Survival (also available for download on
This is what Newswire says about it:

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The Cultural Politics of Sleep

Nicole Eugene recently defended her Masters Thesis called Potent Sleep: The Cultural Politics of Sleep (PDF) on a topic that I find fascinating:

Why is sleep, a moment that is physiologically full and mentally boundless, thought to be a moment of absence and powerlessness? Where did this devalued notion of sleep come from and how can we situate sleep studies within a continuation of a historical processes and economic infuences? In other words, how does sleep effect and exist within systems of power? To answer these questions I turn to a range of scholarship and theoretical studies to examine the complexities and dynamics at work within the cultural discourses on sleep. By creating a genealogy of sleep I am able to track the way notions of sleep have changed and evolved over time. I develop a theoretical framework to examine how the Enlightenment effected notions of sleep by strengthening a cultural disposition for logical, rational and phonomenological modes of knowledge. I find that the advent of modernity is signified by the moment in which sleep, darkness and unknowing become negative while being awake, light and knowledge become positive. To understand how sleep (and sleep studies) operates in contemporary situations I examine them within the economy of time in which clock time is conflated with money. Here I also visit the way sleep functions in relation to work in a neo-Taylorist management era. I offer an account of sleep’s connections to passivity within the patriarchal systems of thought. I determine that the cultural politics of sleep and sleep disorders point to a rift in the Western Self because of a presumed simultaneity of thinking, acting and being. I have engaged in a range of disciplines and use theory, historical studies, textual analysis , and autoethnography as methodologies to outline some of the major cultural discussions that surround sleep.

And she is not the only one in the world interested in cultural, social and political aspects of sleep. I wish someone would pay for me to go and liveblog the Workshop: New Directions in the Social and Cultural Study of Sleep to be held in Vienna on 7-9 June 2007:

This international and interdisciplinary workshop aims at exploring new directions in the study of sleep from the perspectives of the Humanities, Social and Cultural Sciences. The aim is to raise awareness of the social, cultural, political, and environmental influences on sleep behaviour and to describe in detail variations of sleep patterns in different countries and social groups as well as the meanings people attribute to their sleep and sleep-related behaviour.

Once I read the 191 pages of Nicole’s thesis (and I’ll have to find some time to do it), I will post my thoughts on it here, so stay tuned.

No, light behind the knee does NOT shift the clock!

For science bloggers, a study older than a week is often too old to blog about. For scientists, last five years of literature are the most relevant (and many grad students, unfortunately, never read the older stuff). I thought that for journalists, 24-cycle was everything. Apparently not.
Northwest Explorer’s ‘Senior Life’ columnist is having a Senior Moment, I guess. In this article about Seasonal Affective Disorder, he mentions a study that is several years old and, what’s worse, has been shown to be wrong. No, the mammalian circadian clock CANNOT be reset by shining a light at the region of the leg just behind the knee.
When that study came out in Science several years ago (in 1998), there was quite a media frenzy about it. However, a few months later, while the PI (Dr.Campbell) was still publically defending the study, the co-authors and other lab members were already privately conceding that they could not replicate the data in their own lab. No need to mention that several labs have immediatelly tested the proposition, both in humans and in other mammals, and nobody could get to replicate the effect. While the study was never officially retracted, it quietly went away – there is probably not a single person in the field, Dr. Campbell included, who still believes in this. Except this columnist. And his unfortunate readers.
For more information about SAD, see here.

New York Times Gets It Right, Just To Screw Up At The End In Blind Adherence To The He Said/She Said Journalism

New York Times Gets It Right, Just To Screw Up At The End In Blind Adherence To The He Said/She Said JournalismNow behind the Wall, but plenty of excerpts available in this March 26, 2005 post…

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Does Tryptophan from turkey meat make you sleepy?

Does Tryptophan from turkey meat make you sleepy?Well, it’s Thanksgiving tomorrow night so it’s time to republish this post from last year, just in time for the ageless debate: does eating turkey meat make you sleepy? Some people say Yes, some people say No, and the debate can escalate into a big fight. The truth is – we do not know.
But for this hypothesis to be true, several things need to happen. In this post I look at the evidence for each of the those several things. Unfortunately, nobody has put all the elements together yet, and certainly not in a human. I am wondering…is there a simple easily-controlled experiment that people can do on Thursday night, then report to one collecting place (e.g., a blog) where someone can do the statistics on the data and finally lay the debate to rest? Any ideas?
Also, I will add the comments that the post originally received and I hope for new comments from people with relevant expertise. Is Trp Hxlse really a rate-limiting enzyme? If so, why gavaging chickens and rats with Try increases plasma melatonin? Is it different in humans? You tell me!
(originally posted on November 25, 2005)

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Reverend William Paley’s Circadian Clock

Reverend William Paley's Circadian ClockAn oldie but goodie (June 12, 2005) debunking one of the rare Creationist claims that encroaches onto my territory.

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Eight Hours a Circadian Rhythm Do Not Make

Blogging on Peer-Reviewed Research

Eight Hours a Circadian Rhythm Do Not MakeThis post is a relatively recent (May 24, 2006) critique of a PLoS paper.

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It’s not the quantity, but timing

Study says no video games on school nights:

According to Dr. Iman Sharif, the results were clear-cut. “On weekdays, the more they watched, the worse they did,” said Dr. Sharif. Weekends were another matter, with gaming and TV watching habits showing little or no effect on academic performance, as long as the kids spent no more than four hours per day in front of the console or TV. “They could watch a lot on weekends, and it didn’t seem to correlate with doing worse in school,” noted Dr. Sharif.

The study was using self-reporting by kids, which has its problems, but is OK in this case, I think. The key information they did not gather was the timing of game-playing and TV watching.
On schooldays, the only time they can do this is late in the evening, after homework and dinner and sports and everything else have been done. Exposure to light from the screens, as well as the emotional involvement (perhaps raised adrenaline?) phase-delays the kids’ already delayed circadian clocks. Instead of getting 9 hours of sleep, they get 5 or 6. Of course they perform miserably at school and the athletic field, feel lousy and misbehave – they are chronically sleep-deprived.
On weekends, kids are likely to play and watch in the morning or early afternoon, which does not affect the phase of their sleep-wake cycle.
I let my kids play games first thing when they come home from school. They do homework later – it gradually puts them to sleep so they are not sleep deprived.
Hat-tip: Ed Cone.

Alternative sleep therapies

Over 1.6 Million Americans Use Alternative Medicine For Insomnia Or Trouble Sleeping:

A recent analysis of national survey data reveals that over 1.6 million American adults use some form of complementary and alternative medicine (CAM) to treat insomnia or trouble sleeping according to scientists at the National Center for Complementary and Alternative Medicine (NCCAM), part of the National Institutes of Health.
Those using CAM to treat insomnia or trouble sleeping were more likely to use biologically based therapies (nearly 65 percent), such as herbal therapies, or mind-body therapies (more than 39 percent), such as relaxation techniques. A majority of people who used herbal or relaxation therapies for their insomnia reported that they were helpful. The two most common reasons people gave for using CAM to treat insomnia were they thought it would be interesting to try (nearly 67 percent) and they thought CAM combined with a conventional treatment would be helpful (nearly 64 percent).

I don’t really know what to think. On one hand, someone is making a lot of money on this. On the other hand, placebo effect may be quite effective for relaxing a person enough to fall asleep. Meditation certainly will help a person relax – it is so boring you have to fall asleep after a while. And who knows, one of those therapies may actually have some effectiveness after all – we don’t know because it was never tested. On the other hand, many herbal remedies, because they are never tested and approved, may contain some nasty chemicals that can kill you. Such deadly molecules were discovered in some brands of melatonin a few years back. So, they are not safe even if they are effective. I’d like to see Orac and Abel comment on this.

In addition to looking at the data on CAM use and insomnia, the researchers also looked at the connection between trouble sleeping and five significant health conditions: diabetes, hypertension, congestive heart failure, anxiety and depression, and obesity. They found that insomnia or trouble sleeping is highly associated with four of the five conditions: hypertension, congestive heart failure, anxiety and depression, and obesity.

All of those connecitons have been seen before and some of those have been studied in quite a lot of detail. Unfortunately, there appears to be a vicious cycle – these conditions negatively affect sleep and lack of sleep negatively affects these conditions.

When Should Schools Start in the morning?

When Should Schools Start in the morning?The fourth part of a four-part series on the topic, this one from April 02, 2006….

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More on sleep in adolescents

More on sleep in adolescentsThis is the third part of the series on the topic, from April 01, 2006…

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ClockNews – Adolescent Sleep

ClockNews - Adolescent Sleep
Here is the second post on the topic, from March 28, 2006. A couple of links are broken due to medieval understanding of permalinks by newspapers, but you will not miss too much, I hope….

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Sleep Schedules in Adolescents

Blogging on Peer-Reviewed Research

Sleep Schedules in AdolescentsEarlier this year, during the National Sleep Awareness Week, I wrote a series of posts about the changes in sleep schedules in adolescents. Over the next 3-4 hours, I will repost them all, starting with this one from March 26, 2006. Also check my more recent posts on the subject here and here…

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Adolescent Sleep Schedule

This kind of ignorant bleating makes me froth at the mouth every time – I guess it is because this is my own blogging “turf”.
One of the recurring themes of my blog is the disdain I have for people who equate sleep with laziness out of their Puritan core of understanding of the world, their “work ethic” which is a smokescreen for power-play, their vicious disrespect for everyone who is not like them, and the nasty feeling of superiority they have towards the teenagers just because they are older, bigger, stronger and more powerful than the kids. Not to forget the idiotic notions that kids need to be “hardened”, or that, just because they managed to survive some hardships when they were teens, all the future generations have to be sentenced to the same types of hardships, just to make it even. This is bullying behavior, and disregarding and/or twisting science in the search for personal triumphalism irks me to no end.

I hated getting up early, too. I still hate it, and I’m so far beyond growth hormones that I don’t even remember how they felt. But I do remember that in middle and high school, I dragged myself out of the house at 5 a.m. every day of the week to deliver papers before I caught the 6:45 a.m. bus to school. I never fell asleep in class. Neither did anybody else. And something caused me to grow 6 inches and add 35 pounds between sophomore and junior year. At the end of that kind of day, complete with cross-country, basketball or track, I had no trouble falling asleep at 10 p.m.

He said that he grew up in height and weight when he was in high school. Who knows how much more he would have grown if he was not so sleep deprived (if his self-congatulatory stories are to be believed and he did not slack off every chance he had). Perhaps he would not grow up to be so grouchy and mean-spirited if he had a more normal adolescence.
I don’t know where he got the idea that growth hormone is a cause of the phase-delay of circadian rhythms in adolescence. It could be, but it is unlikely – we just don’t know yet. But, if a hormone is a cause, than it is much more likely to be sex steroids. Perhaps his sleep-deprived and testosterone-deprived youth turned him into a sissy with male anxiety he channels into lashing at those weaker than him?

In previous centuries, adolescents in an agrarian society got up at 4:30 or 5 a.m. with their parents to milk the cows or do any other of a long list of chores. Did growth hormones pass them by? Where were the “studies” that showed they really needed to go to bed after midnight and sleep until 10? And why weren’t their parents all being reported to the DSS? Oh, that’s right, there was no DSS. How did that generation survive?

He assumes that in times before electricity, teenagers used to wake up and fall asleep at the same time adults did. Well, they did not. Studies of sleep patterns in primitive tribes show that adolescents are the last ones to wake up (and nobody bashes them for it – it is the New Primitives with access to media that do that) and the last ones to fall asleep – they serve as first-shift sentries during the night watch.

Even in this, the 21st century, kids who enter the military at 17 find that they can fall asleep easily at 9:30 or 10, because they know they’re going to be getting up at 4:30 or 5. Apparently the Army hasn’t read the study on circadian rhythms.

Actually, the military being the most worried by this problem is funding a lot of research on circadian rhythms and sleep and has been for decades. Because they know, first hand, how big a problem it is and that yelling sargeants do not make alert soldiers.

Kids, if you need more sleep, my study shows there’s a simple way to get it. Turn off – I mean “power down” – the cell phone, the iPod and the computer sometime before 11 p.m. Turn off the TV. Turn off the light. Lie down in bed and close your eyes.

…and sit in the dark for the next four hours, heh?
This being the beginning of the school year, I can expect to see more of such nonsense printed in the MSM and on blogs soon, so I may repost (tomorrow) some of the stuff I have already written against the societal equation of sleep with laziness in general, as well as specifically concerning adolescents (see this, this, this, this and this, for instance).
What especially drives me crazy is that so many teachers, people who work with adolescents every day, succumb to this indulgence in personal power over the children. It is easier to get into a self-righteous ‘high’ than to study the science and do something about the problem. It is easier to blame the kids than to admit personal impotence and try to do something about it by studying the issue.
I am also currently reading a very good National Academies Press book on the topic of sleep in teenagers which I intend to review soon, as well as use as a source for future rants on the topic.
Addendum: Alon Levy extends this discussion to the general issue of ageism as a conservative way to supress change by supressing the habringers of change – the next generation. Excellent read.
I’d like to go in a slightly different direction – the issue of Moral Order (scroll down to the “Adults Over Children” subheading). Of course, adults have moral authority over children. But what it means, i.e., how is this phrase understood and put to practice, differs between authoritarian/conservative and authoritative/liberal worldviews.
A conservative thinks about his child: “I am good and you are bad. I will beat the sh**t out of you for every little transgression and I hope that will teach you well. Learn to love the rod, because the discipline I am giving out today will turn into your self-discipline later. Once you are 18, get the hell out of my house – by that time you should be as moral as I am now.”
That is the recipe for the development of the External Locus of Moral Authority.
A liberal thinks about his child: “I am older, thus more educated, experienced and mature than you are. You are a good child and have a potential to become a deeply moral person. I am here to help you and guide you in solving day-to-day moral dilemmas so, by the time you are an adult, you will naturally strive to do good and behave ethically.”
That is the recipe for the development of the Internal Locus of Moral Authority.

Deceptive Metaphor of the Biological Clock

Sometimes a metaphor used in science is useful for research but not so useful when it comes to popular perceptions. And sometimes even scientists come under the spell of the metaphor. One of those unfortunate two-faced metaphors is the metaphor of the Biological Clock.
First of all, there are at least three common meanings of the term – it is used to describe circadian rhythms, to describe the rate of sequence change in the DNA over geological time, and to describe the reaching of a certain age at which human fertility drops off (“my clock is ticking”).
I prefer the Rube-Goldberg Machine metaphor for the mechanism underlying circadian rhythms, but apparently more people know what a clock is than what a Rube-Goldberg Machine is so it appears that we are stuck with the Clock Metaphor for a while.
Once you have a clock metaphor, it is easy to see a clock everywhere you look. Like seeing nails with a hammer in your hand, a researcher in choronobiology is likely to see timing everywhere – I know, I do it myself.
And sometimes this approach pays off – there is definitely a link between circadian and developmental timing in Nematodes, between circadian timing and timing of the love-song in Drosophila, between circadian and seasonal timing, to name some of the few well-known connections, each discovered by a circadian biologist intirgued by the possibility that a clock at one domain (days) may also be involved in timing at other domains (miliseconds, hours, weeks or years).
One of the most touted, yet the most tenuos connection is that between circadian timing and timing of aging and death. Much funding has already been poured into studying this, but, apart from figuring out how circadian rhythms themselves change with age (yup, like everything else, the clock gets a little sloppy and the rhythms get fragmented so you tend to nap more often), no such link has been found yet.
But funding needs to be renewed, and it is just so easy to mix metaphors here – “my clock is ticking” and “my circadian clock is ticking” are so easy to sell together as a package.
Thus, I was not too impressed when I saw this press release: Link Between The Circadian Clock And Aging:

Studying a strain of transgenic mice lacking the core circadian clock gene, Bmal1, Dr. Antoch and colleagues determined that BMAL1 also plays an important role in aging. Bmal1-deficient mice display a marked premature aging phenotype: By 4-7 months of age, the Bmal1 knockout mice experience weight loss, organ shrinkage, skin and hair weakening, cataracts, cornea inflammation and premature death.
The researchers went on to show that BMAL1’s influence on the aging process is due to its previously established role in protecting the organism from the genotoxic stress. Some BMAL1-deficient tissues – like the kidney, heart and spleen – accumulate aberrantly high levels of free radicals. The scientists believe that oxidative stress may underlie premature aging in these animals.
Future research will be aimed at delineating BMAL1 target genes involved in the aging process, with the ultimate goal of elucidating molecular targets for the rational design of drugs aimed at alleviating specific, age-related pathologies. “The involvement of BMAL1, the key component of the molecular clock, in control of aging, provides a novel link between the circadian system, environment and disease and makes circadian proteins potential drug targets,” explains Dr. Antoch.

If you knock out a gene or two, you get messed-up animals. Genes do not work in isolation – they are parts of multiple networks. Knocking one out will mess up multiplenetworks of genes, thus multiple processed in cells. Cells will then compensate fine-tuning other processes, etc. In short = knockout animals are sick animals.
I was going to completely ignore this, but then I saw this nice put down: Surprisingly Few Processes Can Be Thrown Into Reverse:

You should also bear in mind that the appearance of accelerated aging is by no means an indicator that accelerated aging is in fact taking place. It was something of a big deal that certain human accelerated aging conditions were shown to actually be accelerated aging, for example. As another example, diabetes looks a lot like faster aging in many respects, but it isn’t. Surprisingly few biochemical processes are open to this sort of “let’s find out how to throw it into reverse” logic, but the funding game requires one to pitch the next proposal ahead of time and on the basis of your latest research.

Exactly. Read the whole thing and do not buy stock in synthetic BMAL just yet….

Circadian Quackery

Believe me, I love the word “circadian”. It is a really cool word, invented by Franz Halberg in the late 1950s, out of ‘circa’ (Latin – “about”) and diem (“a day”), to denote daily rhythms in biochemistry, physiology and behavior generated by the internal, endogenous biological clocks within living organisms.
It’s been a while since the last time I found someone mistaking the word for ‘cicada’ which is a really cool insect. ‘Circadian’ has become quite common term in the media and, these days increasingly, in popular culture. Names of some bands contain the word. A few blogs’ names contain the word. I guess the word has cool modern scientific connotations, sounds like something from Star Trek, and on top of it has the ever-alluring association to the shape of the circle and the endless cycle of Time. Thus, it has the New-Agey air of a mix of scientific and mystical to it.
That does not mean that people know what the word means. I’ve seen quite a lot of confusion about the meaning of it on blogs and elsewhere. It was just a matter of time until the word was misappropriated by quacks. And yes, it has happened. I have recently found two examples of medical quackery with the word “circadian” prominently displayed. Let me show you why both are utterly wrong and what is the commonality between the two: [under the fold]

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All Politics Is Local

This week, it took me quite a while to figure out how to answer the Ask a ScienceBlogger question: “What are some unsung successes that have occurred as a result of using science to guide policy?”
As a relative newcomer to the United States, and even more a newcomer to American politics, I was not around long enough to pay attention to various science-driven policies of the past. Most of what I know are far from “unsung” successes – from Manhattan Project, through Clean Air and Clean Water acts, to the EWndangered Species Act, to the international Kyoto Protocol. Dealing with DDT, DES, thalidomide is also well-known. The space program is quite well sung! Various policies in other countries are also well known at least to the local population.
So, I thought, I should probably take a look at some issues that, informed by science, became policy at the state or local level. Then, my wife reminded me about the topic I know something about, as I have written about it several times before, e.g., here, here and here.
That’s right. Forward-looking school systems in reality-based communities around the country have, over the last several years, implemented a policy that is based on science – sending elementary school kids to school first in the morning, middle-schoolers next, and high-schooler last. This is based on the effects of puberty on the performance of the human circadian clock. For teenagers, 6am is practically midnight – their bodies have barely begun to sleep. Although there have been some irrational (or on-the-surface-economics-based) voices of opposition – based on conservative notions of laziness – they were not reasonable enough, especially not in comparison to the scientific and medical information at hand, for school boards to reject these changes.
So, click on the links above for my long-winded rants on the topic, both the science part and the policy part. I am very happy that my kids are going to school in such an enlightened environment, and I am also happy to note that every year more school systems adopt the reasonable starting schedules based on current scientific knowledge.

Take a Merlot pill?

Melatonin may be found in grapes

MILAN, Italy, June 16 (UPI) — Scientists in Italy say they have discovered that the grapes used in popular red wines may contain high levels of the sleep hormone melatonin.
Melatonin is naturally secreted by the pineal gland in the brain, especially at night, and it tells the body when it is time to sleep, according to researcher Iriti Marcello at the University of Milan.

Hey, hey, what do you say:

Until recently, melatonin was thought to be exclusively produced by mammals, but has recently been discovered in plants.

Excuse me, but we’ve known for decades that melatonin is produced by all vertebrates, many, many invertebrates, some protists (including sea kelp), and, yes many plants. Bananas are famous for their high melatonin content.

Iriti’s study, published in the Journal of the Science of Food and Agriculture, discovered high levels of melatonin in Nebbolo, Merlot, Cabernet Savignon, Sangiovesse and Croatina grape varieties.
“The melatonin content in wine could help regulate the circadian rhythm — sleep-wake patterns — just like the melatonin produced by the pineal gland in mammals,” says Marcello.
However, Richard Wurtman of the Massachusetts Institute of Technology, says he is unconvinced and believes further research is needed to determine whether the compounds discovered are melatonin — or something very similar.

Wonder why Wurtman said this? I’d need to look at the paper – why is it considered to be iffy. Melatonin assays are pain in the behind to do, but they work.
Anyone, whatever benefits melatonin may have to put one to sleep in the evening probably require imbibing vast quantities of wine which also contains alcohol which fragments sleep (or eating a few pounds of grapes not selected for table use) – thus countering the effects of melatonin. Cute idea, anyway.

Brain Region Linked To Fly Slumber

When a news release states that a brain region is crucial for something, one is led to believe that this is the MAIN center controlling that function. If it is crucial for thermoregulation than it is the center for thermoregulation and without it the animal does not thermoregulate. Or am I misunderstanding English (it is a second language for me, after all)?
So, when the article starts with: “Researchers at Northwestern University have pinpointed a brain area in flies that is crucial to sleep, raising interesting speculation over the purpose of sleep and its possible link with learning and memory,” I expect to see total sleep loss when the brain region is deleted. But, “How the mushroom bodies control sleep is uncertain, but Allada and colleagues show that if the area is destroyed chemically, flies sleep less,” suggesting that a sleep center (if such exists at all – it may be a distributed brain function even in insects) is elsewhere.
Both the Allada study and the Seghal study are excellent and the information is really exciting, but why does a news release have to go beyond, far beyond…

SAD is a different kind of depression

So, Wellbutrin is now officially a drug for treating Seasonal Affective Disorder. And chocolate is so unofficially. But, those may only take the edge off of the symptoms – they cannot affect the underlying causes.

Everything You Always Wanted To Know About Sleep (But Were Too Afraid To Ask)

This post is perhaps not my best post, but is, by far, my most popular ever. Sick and tired of politics after the 2004 election I decided to start a science-only blog – Circadiana. After a couple of days of fiddling with the templae, on January 8, 2005, I posted the very first post, this one, at 2:53 AM and went to bed. When I woke up I was astonished as the Sitemeter was going wild! This post was linked by BoingBoing and later that day, by Andrew Sullivan. It has been linked by people ever since, as recently as a couple of days ago, although the post is a year and a half old. Interestingly, it is not linked so much by science or medical bloggers, but much more by people who write about gizmos and gadgets or popular culture on LiveJournal, Xanga and MySpace, as well as people putting the link on their and stumbleupon lists. In order to redirect traffic away from Circadiana and to here, I am reposting it today, under the fold.
Update: This post is now on Digg and Totalfark. I urge the new readers to look around the site – just click on the little SB logo in the upper left corner. Also, several points made briefly in this post are elaborated further over on Circadiana, as well as here – just browse my Sleep category.

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