Blue Light at Night Morning Delight
Do you ever see that episode of the original Star Trek in which Spock is accidentally – and temporarily – blinded when he is exposed to ultra-bright light to drive out a parasite? For people who like to know such things, it was episode 29, entitled Operation: Annihilate!
In the end it turns out that he only needed to have been exposed to one invisible wavelength of light. Naturally enough, being Star Trek it all comes out all right in the end.
I was reminded of this as I examined some extraordinarily important recent research from Thomas Jefferson University in Philadelphia. We have known for a long time that light is an effective treatment for seasonal affective disorder (SAD). However, until now, nobody has been able to determine the best wavelength to use. This new research found that the most effective wavelength was blue. It is thought that blue light therapy may help a great many more things than SAD.
SAD is one of a group of disorders involving our circadian rhythms. Many experts are currently trying to establish the relationship between SAD and another major disturbance of circadian rhythms: bipolar disorder. They are certainly not the same thing, but they are closely related to each other. Some other circadian rhythm disturbances that may respond to blue light are sleep disturbances, jet lag, sleepiness during shift work and spaceflight.
It has always been assumed that the brain’s major pacemaker – the suprachiasmatic nucleus (SCN) – only responded to bright light at a certain time of day. The SCN regulates the production of melatonin by the pineal gland. The fact that lower-intensity blue light is more effective than the most visible kinds of light is part of a body of evidence that there is a separate photoreceptor system within the human eye. The system that resets the body clock to the 24-hour day is different from the rods and cones used in regular vision.
In linked research by the same investigators, as well as a team from and Brigham and Women’s Hospital and Harvard Medical School in Boston, blue light was shown to directly reduce sleepiness. People exposed to blue light were able to sustain a high level of alertness during the night when people usually feel most sleepy. The results suggest that light may be a powerful countermeasure for the negative effects of fatigue for people who work at night.
There is more to this research: breast cancer is linked to fluctuations in human circadian rhythms, with higher rates in industrialized countries where there is a great deal of exposure to artificial light at night. It has been suggested that melatonin may be a link between artificial light and breast cancer. Blue light may perhaps mitigate some of the effects of light on suppressing melatonin.
There is another point to be made here. Many people teach techniques of being able to see the human aura. Many of the techniques of the “See the aura in 30 seconds” type, are no more than visual illusions. But there is another group of techniques that involves the use of peripheral vision to gradually become aware of the fields around people, animals and plants. By a strange “conincidence” the ancients identified the pineal gland with the “third eye.” Have the researchers inadvertently found a biological mechanism for seeing auras?
“Sleeplessness is a desert without vegetation or inhabitants.”
–Jessamyn West (American Writer, 1902-1984)
Exercise and Mood
Most people who exercise on a regular basis soon begin to notice that if they miss a day or two, it will quickly have an effect on their mood and motivation. There’s recently even been some research to confirm it. Many years ago it was shown that one of the mechanisms for the “Runner’s high,” was the production of endorphins and we now have a great deal of research that is revealing the fundamental mechanisms linking exercise and mood.
Though the link between exercise and mood has been recognized for decades, in the last few years we have seen an increasing body of evidence that exercise can have a useful effect on people with mood disorders. The evidence is extensive (For example: 1. 2. 3.) and is now so strong that many clinicians – and certainly all practitioners of Integrated Medicine – routinely recommend physical exercise as part of a package of health care. There is particularly good evidence that exercise will help with some of the less common types of depression. An exercise program may particularly benefit women with progesterone-related premenstrual mood disturbances.
We now have some good evidence about the mechanisms by which exercise can improve mood. Researchers in China did some experimental work in rats with what they called “Chronic unpredictable stress.” It is just what it sounds like. If the little critters keep getting stressed, they develop many of the signs of depression: they show loss of appetite, social withdrawal and a reduction in exploratory behavior. We could say that the repeated stress reduces their resilience. Chronic stress causes dysfunction in the hormonal system that links the hypothalamus and pituitary glands at the base of the brain, with the adrenal glands that are perched atop the kidneys.
The researchers then gave some of the rats the opportunity to exercise on a wheel. The exercising rats had an increase in the amount of a growth factor called brain-derived neurotrophic factor (BDNF) in a key region of the brain called the hippocampus. In the non-exercisers, the levels of the growth factor went down as they experienced more and more stress. Exercise also smoothed out stress-induced rises in the hormone cortisol.
This is particularly interesting because previous research had shown us that exercise can increase BDNF levels in the brains of stressed and unstressed animals. We also know that if an antidepressant is going to work, it has to be able to stimulate the production of BDNF in the hippocampus of the brain.
One thing that has not been much studied is the impact of exercise on sleep architecture. Most exercisers know that a good workout, run or hike can make you sleep like a log. And there is increasing evidence that correcting sleep disturbances can be a most effective way of improving mood. So much so that many of us now believe the sleep disturbances underlie many mood disorders, rather than sleep disturbances being symptoms of sleep disorder.
My conclusion from reading the literature and working with countless individuals is that unless there is a medical contraindication, a combination or weight training and aerobic exercise should be part of the treatment program for anyone with depression. The biggest problem is motivating someone with depression t do something like exercise. Sometimes it is necessary to wait until the primary treatment has taken hold. Though we have often had a great deal of success by using some of the motivational systems that I’ve described in Healing, Meaning and Purpose.
Breathing
“Without mastering breathing, nothing can be mastered.”
–George Gurdjieff (Armenian-born Adept, Teacher and Writer, c.1873-1949)
I strongly recommend breathing. It’s actually one of my favorite pastimes….
Of course breathing is all-important, but it is just as important to ensure that you are breathing in good quality air. Scattered throughout the world are weather fronts accompanied by hot dry winds of ill repute:
- The Santa Ana Winds of Southern California,
- The Mistral of France
- The Khamsin of North Africa
- The Foehn of Switzerland
- The Sharav in Israel
- The Chinook of Canada
- The Sirocco in parts of the Mediterranean
- The Xlokk of Malta
- The Zonda in Argentina
- The Halny of the Carpathian Mountains
These are just some of these winds, that have been known for centuries to precipitate a variety of symptoms in the exposed population, including depression, irritability, insomnia and headaches. The explanation of these effects is an increase in the number of positive ions in the atmosphere, which alter the amount of serotonin in some parts of the brain. I was consulted about an epidemic of headaches amongst people working in an electrically insulated room. It soon became clear that the setup had allowed an enormous concentration of positive ions, and once they installed a negative ionizer virtually all the headaches stopped. We believe that many of the beneficial effects of high altitudes or of being near waterfalls of fountains spring from the way in which they generate large numbers of negative ions.
Poor oxygenation of the lungs has been known for many years to be associated with disease. Pulmonary tuberculosis classically affects the upper lobes of the lung, where there is the poorest oxygenation, and it has been known for a century that people suffering from a blockage of the mitral valve of the heart, which leads to high blood pressure in the lungs, do not get tuberculosis in that part of the lungs.
Conscious control of the breath enables us to modulate the activity of the autonomic nervous system. Specific types of breathing can induce specific psychological and physical effects.
We usually breathe through one nostril at a time. Either the right or left nostril is dominant for anywhere from 45 minutes to two hours. You then switch sides. This is known as the nasal cycle, and is one of the faster circadian rhythms. The popular yogic practice of single nostril breathing is thought to feedback directly into the hypothalamus of the brain. You can learn to use this to your advantage. If you are right handed, if you direct your focus onto opening the right nostril, you may well find an increase in salivation, which is an aid to good digestion. A useful trick that we have used for many years is at bedtime to start by lying on your left side, which has the effect of opening the right nostril, and after ten minutes roll onto your right side for sleep. Again you reverse this if you are left hand dominant. It seems that this simple trick lowers your core temperature, which is one of the main determinants of sleep. There is some research that opening the right nostril increases body temperature, while opening the left has a calming effect. These techniques are often very helpful. Apart from these physical effects, using the breath is one of the quickest ways to learn to sense the subtle forces of the body.
You may already have some breathing practice that you like, and by all means continue using it. If you need a new one, the simplest that I have ever been taught, and that I have used with countless students and patients is this:
Count your breaths. Breathe deeply using your abdominal muscles, so that you are drawing more air into your lungs. Stop immediately if you feel faint or dizzy. As thoughts come up, keep concentrating on the incoming and outgoing breath. Gradually slow the breath, by extending the pause between the inhalation and exhalation.
I always make myself unpopular when I insist that people check with a healthcare provider before stating any exercise plan, including breathing. But I’m going to say it anyway. It just makes good sense!
“Controlled deep breathing helps the body to transform the air we breathe into energy. The stream of energized air produced by properly executed and controlled deep breathing produces a current of inner energy which radiates throughout the entire body and can be channeled to the body areas that need it the most, on demand. It can be used to fuel a specific physical effort, such as tennis or jogging. Or you can use this current of inner energy to relieve muscular tension throughout the body, revitalize a tired mind, or soothe localized aches and pains.”
–Nancy Zi (American-born Chinese Opera Singer, Voice Teacher and Qigong Expert)
Hypnagogia: The Waking Dream
Most of us have experienced the brief transition between wakefulness and sleep as we fall asleep. This is the hypnagogic state, though it has been known by many names: “the borderland state," the “half-dream state,” the “pre-dream condition.” The name for these strange hallucinations is “hypnagogia.”
Although there are innumerable books about dreams, there is to my knowledge only one book in English that is dedicated to hypnagogia, by the psychologist Andreas Mavromatis. There are also not that many good websites dealing with the phenomenon, though I’ve found one or two really good ones. This is a little surprising, for the hypnagogic state is one of the most fascinating altered states of consciousness that we can experience without the use of drugs, and there are dozens of spiritual schools that encourage their students to work with these hypnagogic hallucinations. They are different form the hallucinations that may occur in neurological problems: those tend to occupy only one sense at a time, while the hypnagogic hallucinations, though sometimes no more that flashes of light or odd shapes, can be highly complex and involve multiple sensory modalities: what we call multi-modal hallucinations. Some people may feel as if they are floating, and it is not uncommon for people to kick out or grasp as they feel as if they are falling from a great height.
The term “hypnagogic” was coined by the 19th-century French psychologist Louis Ferdinand Alfred Maury, and is derived from two Greek words, Hypnos (Sleep) and agogeus (A guide, or leader). Some years later, the English poet, essayist and psychical researcher Frederic William Henry Myers coined the term, “hypnapompic,” to describe similar phenomena that may occur as we wake from sleep.
Long before Maury, many writers commented on these odd experiences. Here are just a few that I’ve heard about:
- Aristotle spoke of the “affections we experience when sinking into slumber, and the images which present themselves to us in sleep.”
- Iamblichus of Chalcis, the third century Neo-Platonic philosopher, wrote of the “voices” and “bright and tranquil lights” that came to him in the condition between sleeping and waking, that he believed were a form experience sent by God.
- There is some evidence that the alchemists of the Middle Ages made use of a form of hypnagogia during their meditations, preparations and distillations. I’ve seen it suggested that the weird characters and eerie landscapes that seem to fill alchemical illustrations might have been the fruits of focusing on hypnagogic hallucinations, though they could just as easily have come from dreams or drugs.
- In 1600, the Elizabethan astrologer and occultist Simon Forman wrote of his apocalyptic visions. He saw mountains and hills that came rolling against him on the point of sleep and beyond which he could see vast boiling waters.
- Thomas Hobbes spoke of images of lines and angles seen on the edge of sleep accompanied by an “odd kind of fancy” to which he could give no particular name.
- Emmanuel Swedenborg the 18th century philosopher, scientist and visionary developed a method of inducing and exploring hypnagogic states, during which he claimed to have traveled to Heaven, Hell and other planets. He recorded several other techniques that he used to gain his insights, including a particular type of hyperventilation.
- The theosophical writer Oliver Fox used the hypnagogic hallucinations as a “doorway” through which he was able to go astral traveling.
- Rudolf Steiner, advised that the best time for communicating with the dead was in the period between waking and sleep. He claimed that if you asked the dead a question as you fell asleep, they would answer you the next morning His records look very much like hypnagogic hallucinations.
- The Russian writer and philosopher P.D. Ouspensky is someone else who made a detailed study of hypnagogia. Like many of the others that I’ve mentioned, he made a number of interesting discoveries about the Universe while in this state. It is these insights, and their similarities across cultures that suggest that there’s more to hypnagogia than random neuronal firing.
It is interesting that although hypnagogia can produce millions of different experiences. When people start using them for exploration, they seem to generate many similar insights. This is rather different from the mystical experience. In which peoples’ experiences have similar form, but different content.
The most widely used criteria of the mystical experience were assembled by the English philosopher W.T. Stace, who taught at Princeton for many years:
- Deeply positive mood
- Experience of Union
- Ineffable sense
- Enhanced sense of meaning, authenticity and reality
- Altered space and time perception/transcendence
- Acceptance of normally contradictory propositions
I shall have more to say about mystical experiences in another posting.
For now, if you are interested in doing some self-exploration, and you are not using either medications or alcohol, the hypnagogic state is a great place to start. Occasionally people find the exploration scary, so only do this if you are up to it, and don’t if you are given to nervous or psychological problems. When I’m working with people I always ensure that they are in tip top condition before trying ANY kind of psychological exploration.
Try becoming aware of the transition between wakefulness and sleep. At first you will fall asleep, but with a small amount of practice, most people can quickly begin to keep themselves in the state, and then start exploring. Many people find that they get some profound intuitions while in the hypnagogic state, and unlike the kinds of “insights” that people get while under the influence of drugs or alcohol, they make sense in the morning. Relax, keep a diary, take it in easy stages, and see what you can discover for yourself. If you come across anything unpleasant, stop, and we can try some different exercises.
Pramipexole
Pramipexole is a remarkably interesting medicine about which you are likely to hear a lot in the near future. It is an agonist, which means that it has a positive effect, on D2 dopamine receptors and also on a little-known group of dopamine receptors, known as the D3 group. If you want to get really clever the dopamine receptor D3 group is abbreviated to DRD3. Pramipexole has been in use for almost a decade in the treatment of Parkinson’s disease, and approximately 9.1 million prescriptions for pramipexole have been written in the U.S. since its launch in 1997. It is not without its problems. In Parkinson’s disease it may cause dizziness, involuntary movement, hallucinations, headache, difficulty falling asleep, sleepiness, and nausea. Some people have also had behavioral dyscontrol while taking it.
At a meeting in Athens in February of 2006, we saw confirmation of something that had been shown in previous research: pramipexole seems to be a very effective treatment for restless legs syndrome (RLS). A study published in the journal Neurology has given us a more detailed understanding of the risks and benefits of pramipexole.
The investigators report a 12-week, multicenter, double-blind, randomized, placebo-controlled study of fixed daily doses of pramipexole (0.25 mg, 0.50 mg, and 0.75 mg) involving 344 patients with moderate to severe RLS. Data from 339 patients were analyzed to evaluate the effect of pramipexole treatment on efficacy and safety. The mean age of patients was 51.4 years and the mean duration of RLS symptoms was 5.1 years. The results were very promising, even though half of the patients on placebo also showed an improvement. The most commonly reported side effect included nausea (19.0%), headache (17.8%), insomnia (10.5%) and somnolence (10.1%).
In Europe pramipexole it has been approved for use in this indication. It is marketed as Sifrol® / Mirapexin® In the United States we currently only have one approved medical treatment for RLS, and that is the GlaxoSmithKline medicine ropinirole (Requip), that works at the same D3 receptors in the brain and spinal cord. Ropinirole is effective in a proportion of people with RLS, but it has also been linked to sleepiness, drops in blood pressure and fainting, so those are included in its label.
RLS may be associated with some other illnesses so I was very interested to see two reports of the use of pramipexole in bipolar depression as well as a report of its possible use in REM Behavior Sleep Disorder.
One of the most exciting potential uses for pramipexole may be in some people with fibromyalgia. I’ve mentioned that fibromyalgia, bipolar disorder and some other psychiatric illnesses may be connected. The idea that we might be able to use just one medicine to support our Integrated Medicine approach is very attractive, and also helps point us toward a deeper understanding of what exactly goes wrong at the physical level in RLS, depression and fibromyalgia.
I’ll keep you posted.
Restless Legs Syndrome and Integrated Medicine
In the last entry we looked at RLS: what it is, and some of the conventional approaches to treating it. I now want to spend a moment talking about some of the other approaches that we have tried. For most of these there is very little evidence, so we use them in conjunction with conventional medicine.
If you want to try any of them, discuss them with your health care provider, so that he or she can guide you toward the best ways of putting treatments together.
- Diet: A low sugar diet helps some people, and it is always worth keeping a food diary for a week to see if there’s any association between something that you’ve eaten and a worsening of your symptoms.
- If you like juicing, there have been a number of anecdotal reports of the use of carrot, celery and spinach juices helping some people. (I am writing this while we are still in the middle of the spinach/E. coli scare, so leave this one out until the FDA has given us the all clear.
- There have been publications about the use of vitamins E and B and folic acid in RLS. Vitamin E can cause a GI upset in some people and if used in too high a dose (above 800IU/day) may elevate blood pressure; folic acid has to be used with caution in people on anticonvulsants. If you try these options, bear in mind that no supplement is likely to work unless it is taken for at least a month.
- Acupuncture sometimes helps: there are three acupuncture points in the legs that come up in the prescription: Urinary bladder 57, Spleen 6 and Stomach 36.
- Homeopathic remedies have been reported to help, and I’ve had some success. The precise remedy always depends on the precise characteristics of the individual, but the most common ones have been Rhus Toxicodendron, Causticum, Tarentula Hispanica and Zincum Metallicum. If you live in a place in which there are good homeopaths available for consultation, it’s another option.
- Several herbal remedies have been reported to help: Passion Flower, Cimicifuga, Valerian, Black Cohosh and Piper Methysticum. Just remember that some of the herbs sold in health food stores don’t contain what they should, and Valerian and Black Cohosh have recently been associated with liver toxicity in some people.
- Here is an old trick from China: take a one inch piece of fresh ginger root and grate it into a bowl of warm water. Then soak your feet in the water for about ten minutes. I’ve never seen that one work myself, by some people whom I respect have.
I also think it important not to neglect the psychological aspects of this problem, and sometimes some psychotherapy can be a helpful adjunct.
Finally, ask yourself what the RLS is trying to teach you.
These are all options that have been tried and have helped some people. If you are not having success from conventional medicine alone, or if you don’t care for conventional medicine, then discuss these options with a professional, use your intuition, and let us know if you have success.
Restless Legs Syndrome
Restless legs syndrome (RLS) is a common (3-15% of the population) and sometimes very unpleasant problem in which people have uncontrollable urges to move their legs. If they do not move, they will begin to feel uncomfortable, painful or odd sensations in their legs, and sometimes also in other parts of the body. The restlessness may last for minutes or even hours. Movement affords people very temporary relief. The sensations are usually between the ankle and the knees, but they can also involve the thighs. If other parts of the body are involved it always makes us question the diagnosis.
The severity of the problem is highly variable, running from a mild annoyance to an incapacitating problem. In most people the symptoms are worse when sitting or at night, and often lead to loss of sleep. Not surprisingly many people feel of exhausted and irritable during the day.
With such enormous variations in the severity of the problem, and even the parts of the legs affected, it is highly likely that RLS is a symptom of a group of illnesses.
The International Restless Legs Syndrome Study Group (IRLSSG) identified four criteria that must be present for an RLS diagnosis:
- An urge to move, usually due to uncomfortable sensations that occur primarily in the legs.
- Motor restlessness, expressed as activity, that relieves the urge to move.
- Worsening of symptoms by relaxation.
- Variability over the course of the day-night cycle, with symptoms worse in the evening and early in the night.
About 80% of the people with restless legs syndrome also suffer from a separate condition called periodic limb movements in sleep (PLMS). Periodic limb movements in sleep are involuntary jerking movements in extremities, usually the legs. You can have PLMS without having RLS, and vice versa.
RLS may start at any age, including early childhood, and is a progressive disease for a certain percentage of sufferers, although it has been known for the symptoms to disappear permanently in some sufferers. The condition runs in families; children of RLS sufferers are more likely than other people to develop RLS.
It has some similarities to a syndrome known as akathisia that occurs in people taking some medications that work in the dopamine pathways of the brain. There are some subtle ways of telling the two apart, but RLS also seems to be caused by disturbances in one of the dopamine pathways of the brain.
It has been known for many years that there is an association between RLS and iron deficiency, but this link is probably not causal: just giving iron only helps a proportion of sufferers. But because of this link, everyone with RLS should have their ferritin levels tested; ferritin levels should be at least 75 mcg for those with RLS. If it’s below this level, iron supplements may help, but they are best administered by a physician, because ferritin needs to be monitored and there are down sides to taking too much iron. In a moment I’ll tell you about some very new research on iron and RLS
Caffeine and other stimulants usually make RLS worse. Restless legs syndrome frequently occurs during pregnancy. About 15% of pregnant women develop RLS symptoms during the last few months of their pregnancy. The sensations usually stop after the woman delivers the baby.
We normally divide RLS into primary and secondary. Primary RLS usually starts before age 40 and the onset is often slow. The RLS may disappear for months, or even years. But it can be progressive and get worse as the person ages.
Secondary RLS often had a sudden onset and may be daily from the very beginning. Apart from pregnancy, secondary RLS is a result of a number of medical conditions, so it is always important to rule them out. They include:
- Iron deficiency anemia
- Macrocytic anemia due to folate or vitamin B12 deficiency
- Diabetes mellitus
- Peripheral neuropathy
- Alcohol abuse
- Some types of cancer, particularly of the lung
- Celiac disease
- Renal failure
- Inflammatory arthritis
There have been reports of associations of RLS with other illnesses, but most seem rare. Interestingly people who undergo surgery often find that RLS symptoms become worse, which may be another clue as to the cause of the problem.
An international conference entitled SLEEP 2006, the 20th Anniversary Meeting of the Associated Professional Sleep Societies took place from June 17-22, 2006 in Salt Lake City, Utah. There were a great many interesting papers this year, including several on RLS
An international group of collaborators presented the results of the first population-based pediatric RLS survey. They used the National Institutes of Health pediatric RLS diagnostic criteria and collected data from over 10,000 families. The criteria for definite RLS were met in 1.9% of 8- to 11-year-olds and in 2% of 12- to 17-year-olds. Two different papers explored the value of using a single screening question to identify possible RLS patients. Those who answered, “Yes,” then answered more detailed questions to determine whether they met the International RLS Study Group diagnostic criteria.
A single screening question can eliminate people without RLS rapidly and direct appropriate subjects to further evaluation. Two groups of researchers found a high level of sensitivity with the question, "When you try to relax in the evening or sleep at night, do you ever have unpleasant, restless feelings that can be relieved by walking or movement?"
As I mentioned, it has been known for decades that RLS may be associated with low iron, and especially with low ferritin levels. These may be present in symptomatic RLS patients during pregnancy and in people with iron-deficiency anemia and end-stage renal disease. Previous studies had suggested that supplemental iron was beneficial for RLS patients with low ferritin levels. One paper presented further evidence of the possible efficacy of supplemental iron in the treatment of selected RLS patients with a prospective, randomized, placebo-controlled, double-blind study of RLS patients with low to normal ferritin levels (15-75 mcg/L). The RLS subjects were given either placebo or iron 325 mg twice daily and were monitored with a validated RLS symptom scale. The preliminary findings showed that the iron supplementation group had significant increases in their ferritin levels and had improved quality of life compared with those on placebo; however, the interim data presented did not show a significant change in the RLS symptom score. The study is ongoing.
Treatment for RLS is based on how disruptive the symptoms are. Apart from iron, people should review their lifestyle and see what changes could be made to reduce or eliminate their RLS symptoms. These include: Finding the right level of exercise (too much worsens it, too little may trigger it)
Eliminating caffeine
Stopping smoking
Reducing alcohol intake
Several drugs have been tried for RLS: Some of the same medications used in Parkinson’s disease, benzodiazepines, anticonvulsants like carbamazepine and gabapentin.
Last month saw the publication of an important paper indicating that the medicine pramipexole, another anti-Parkinsonan drug, helps many people with RLS
In the next article I shall review some of the other approaches used by Integrated Medicine.
Prostate Cancer, Shift Work and Vitamin D
One out of six American men will develop prostate cancer and more than a third of them will experience a recurrence after undergoing treatment, putting them at high risk to die of the disease.
A study from Japan in this month’s issue of the American Journal of Epidemiology, reports prospective research that examined the association between shift work and the risk of prostate cancer incidence among 14,052 working men. Compared with day workers, people who worked rotating shifts were significantly at risk for prostate cancer whereas fixed-night work was associated with a small and non-significant increase in risk. This report is the first to reveal a significant relation between rotating-shift work and prostate cancer. Previous research has found that shift work may be linked to an increased risk of breast and colon cancer.
It’s important not to jump off the deep end: we are long way from saying that sleep disturbance is linked to prostate cancer. But it is another piece of evidence suggesting a link between environmental factors and genes, since there are a number of genes that may increase a man’s risk for prostate cancer.
However, there have now been several reports that disturbances in normal body rhythms might be linked to some cancers and this report adds to that evidence. It has never been shown that the actual sleep disturbance itself is responsible for the slight increase in risk seen in these studies. It could also be that people with abnormal sleep patterns are more likely to be doing something else, for instance smoking or eating junk food that would interfere with sleep and increase people’s cancer risk.
But here’s something to think about: shift workers have been found to have reduced secretion of the sleep-inducing hormone melatonin. Melatonin has also been shown in some studies to have some potential anti-cancer effects. The studies are controversial and certainly not conclusive, despite what one or two melatonin manufacturers may say. But something that is true is that reduced secretion of melatonin has been linked to increased production of sex hormones, which play a role in regulating prostate tissues.
Under normal circumstances, secretion of the hormone is low during daytime, increases soon after the onset of darkness, peaks in the middle of the night, and gradually falls until morning. In shift workers the melatonin cycle becomes disrupted.
There has been some recent evidence that maintaining adequate levels of vitamin D may reduce a man’s risk of prostate cancer.
Another study, this time on pancreatic cancer and led by Northwestern University in Illinois has indicated that taking the US Recommended Daily Allowance (RDA) of vitamin D (400 IU/day) reduces the risk of pancreatic cancer by 43%. It is published in this month’s issue of Cancer Epidemiology Biomarkers & Prevention. This does not mean that we should start taking vitamin D supplements to reduce our cancer risk. But it ties in with research indicating that some exposure to sunlight might actually reduce the risk of some cancers. But all things in moderation: malignant melanoma and basal cell carcinoma of the skin have been increasing with increased exposure to sunlight.
Artificial Light and the Biological Clock
Many of the things that we do to babies and young children have been called into question in recent years.
The debate about doing an excessive number of fetal ultrasounds and high tone deafness seems to have gone away for now. Though not disappeared: there is a paper in the week’s Proceedings of the National Academy of Sciences that revisits this important issue. Then there was the realization that doctors were not good at recognizing and dealing with pain in very young children.
And now there is another one that has worried me for years: what happens to babies who are exposed to constant high levels of light? Doesn’t it damage the development of normal circadian rhythms?
I have just seen a study that seems to confirm some of those fears.
Investigators from Vanderbilt University in Nashville examined the impact of exposing babt mice to constant light. The main biological clock is in the brain, and is located in a region called the suprachiasmatic nuclei (SCN). It is responsible for orchestrating an orderly internal physiological and behavioral cycle. It influences the activity of virtually all our organs, including the brain, heart, liver and lungs. It egulates the daily activity cycles that we call circadian rhythms.
When the mice are exposed to normal variations in light the cells of the SCN quickly become synchronized, and a normal circadian rhythm is established. Constant exposure to light disrupted the development of the SCN and prevented the animals from developing normal circadian rhythms.
This is far from being an academic exercise: each year around 14 million premature babies are born worldwide, and many are exposed to artificial lighting in hospitals. If their biological clocks are not allowed to develop normally, we would anticipate that they would, in later life, have less psychological resilience, and to be prediposed to sleep and mood disorders.
I could conceive of a way to test that experimentally by looking at records of people wth those problems. Secondly, we need to see if reducing unnecessary light exposure would have a real benefit for babies, and for the children and audlts that they will become. I would be astonished if exposing babies to a natural spectrum of light and a natural light cycle did not have enormous benefits for them as they grow up.
Insulin Resistance, Polycystic Ovarian Syndrome and Sleep Apnea
Polycystic ovarian syndrome (PCOS) is a common endocrine disorder that affects between 5-10% of women in the Western World. It is a leading cause of infertility, and although the underlying cause is still speculative, it is very heavily associated with insulin resistance.
There was an International Consensus Workshop sponsored by the European Society of Human Reproduction and Embryology and the American Society of Reproductive Medicine came up with this set of criteria. PCOS is present if a woman has at least two out of three of:
- Oligoovulation and/or anovulation (ovulating only occasionally or not at all)
- Excess androgen (male sex hormone) activity
- Polycystic ovaries (which needs a gynecological ultrasonography) and other causes of PCOS are excluded
There is still a great deal of debate about the precise way to define the syndrome. We are currently preparing a scholarly article on the subject and our literature review has included over three thousand papers.
The combination of an excess of the male (androgenic) hormones and insulin resistance can cause an array of symptoms apart form the menstrual disturbances and infertility, including:
Central obesity
Acne
Hirsutism, while at the same time experiencing alopecia
Skin flaps and dark patches of skin, usually on the neck or in the armpit
Sleep apnea
It is the last of these that I would like to highlight today.
A new study by Dr. Esra Tasali and her colleagues from the University of Chicago has found that in women with PCOS, sleep apnea is, as expected, associated with high fasting insulin levels. Sleep apnea might worsen the metabolic consequences of insulin resistance.
Regular readers may recall that I highlighted the association between insomnia, insulin resistance, weight and diabetes a couple of months ago. Here we have yet more confirmation of this link.
Not getting enough sleep – for any reason – can play havoc with your metabolism. It seems that in women with PCOS, it’s really easy for a vicious circle to become established:
Insulin resistance -> weight gain -> sleep apnea -> insomnia -> more insulin resistance -> more weight gain and so on.
It is important for everyone to know about this association, because chances are that you know someone with PCOS and/or sleep apnea.
