| March 16 2011
Experiments on mice have shown that throwing off their ancient circadian rhythms by artificially altering the length of their days has a substantial impact on their bodies and brains. This suggests that the modern, round-the-clock lifestyle, made possible by electric lighting, could disrupt metabolism and interfere with learning in ways that are only just beginning to be understood.
Researchers put mice through 10 weeks in 20-hour light-dark cycles, instead of their natural 24-hour circadian cycle. After six weeks, the mice got fatter, showed less mental flexibility and were more impulsive.
Science Daily reports:
“The researchers believe that [the effects of an altered circadian cycle] may affect how an individual, whether animal or human, responds to additional challenges to the immune or metabolic systems, such as infection … They are also working on models to understand the impact of different kinds of light-dark shifting such as those experienced by flight crews, shift workers, military personnel and medical residents.”
Sources:
Science Daily February 27, 2011
Dr. Mercola’s Comments:
Time and again, research shows us the hidden price we pay for our 24/7 lifestyles. Lack of sleep due to over-crowded day planners, e-mail, web surfing, and other distractions take a toll on your health whether you realize it or not.
Amazingly, 95 percent of those surveyed in the National Sleep Foundation’s 2011 Sleep in America poll report using some type of electronic device within an hour of going to bed, and about 20 percent reported being awakened by phone calls, text messages or email, at least a few nights a week…
As you probably know, the physiological functions of virtually all organisms are governed by 24-hour circadian rhythms.
When your circadian rhythm—which acts like a built-in time-tracking system—is disrupted by late-night artificial light exposure, or being roused from sleep by beeping phones, it can have a profound influence on your physical and mental health and well-being.
One of the worst things you can do to disrupt your body clock is to engage in regular night shift work. I realize many may not have a choice once they’ve chosen these professions, but it is vital to understand that when you regularly shift your sleep patterns because of a job like police, fire, or ER work, you are in fact sacrificing your health and longevity—in more ways than one.
Round-the-Clock Lifestyle Damages Your Health in a Number of Ways
In this latest study, mice were kept in 20-hour light/dark cycles for 10 weeks to evaluate the effect on their metabolism, mental acuity and behavior. After six weeks, “the disrupted mice got fatter, showed less mental flexibility and were more impulsive than mice kept on their natural schedule,” Science Daily reports.
The authors found changes in metabolic hormones, and “loss of dendritic length and decreased complexity of neurons in the prelimbic prefrontal cortex, a brain region important in executive function and emotional control.”
Since the circadian system “drives” the rhythms of biological activity at the cellular level, disruptions tend to cascade outward throughout your entire body, which explains why the health effects of sleep deprivation and sleep disruption are so numerous.
The Many Ways Disrupted Sleep Patterns Can Impact Your Health
For example, your circadian clock influences your:
Short term memory — Your circadian clock controls your daily cycle of sleep and wakefulness by alternately inhibiting and exciting different parts of your brain through regulating the release of certain neurotransmitters. The part of your brain known as the hippocampus must be excited in order for the things you learn to be organized in such a way that you’ll remember them later.
If your internal clock isn’t functioning properly, it causes the release of too much GABA. According to a previous study, an excess of GABA inhibits your brain in a way that leads to short term memory problems and the inability to retain new information.
Creativity and learning performance – Proper sleep enhances performance, learning and memory by improving your creative ability to uncover novel connections among seemingly unrelated ideas.
Weight gain/loss – In addition to the study above, previous research has also demonstrated that lack of sleep affects levels of metabolic hormones that regulate satiety and hunger. For example, when you are sleep deprived, your body decreases production of leptin, the hormone that tells your brain there is no need for more food. At the same time it increases levels of ghrelin, a hormone that triggers hunger.
Diabetes and heart disease risk — Both too little and too much sleep may increase your risk of type 2 diabetes. A 15-year study of more than 1,000 men found that those getting less than six or more than eight hours of sleep a night had a significantly increased diabetes risk.
A similar pattern has also been observed in the relationship between sleep and coronary heart disease.
Immune system – Research has found that when you are well-rested you are likely to have a stronger immune response to viruses than when you have not gotten enough sleep. It’s believed that the release of certain hormones during sleep is responsible for boosting your immune system.
Cancer risk — Disruption of your circadian clock may influence cancer progression through changes in hormones like melatonin, which your brain makes during sleep, and which is known to suppress tumor development.
Melatonin is an antioxidant that helps to suppress harmful free radicals in your body and slows the production of estrogen, which can activate cancer. When your circadian rhythm is disrupted, your body may produce less melatonin and therefore may have less ability to fight cancer.
Chronic Diseases Made Worse By Lack of Sleep
Furthermore, according to a report in the Journal of the American Medical Association (JAMA), lack of sleep can further exacerbate other serious and chronic diseases, such as:
Parkinson disease (PD)
Alzheimer disease (AD)
Multiple sclerosis (MS)
Gastrointestinal tract disorders
Kidney disease
Behavioral problems in children
Disrupted Circadian Cycle Unleashes Stress
Making matters worse, poor sleeping habits also tends to raise your levels of corticosterone, the stress hormone associated with road rage.
When your body is under stress, it releases hormones that increase your heart rate and blood pressure. Your muscles get tense, your digestive processes stop, and certain brain centers are triggered, which alter your brain chemistry.
Left unchecked, this stress response can eventually lead to a variety of health problems including:
Headaches
Indigestion
Increased anxiety
Depression
High blood pressure
As you can see, the ramifications of engaging in a 24/7 lifestyle runs the gamut from minor stresses to life-threatening health problems! Yet judging by the poll responses mentioned at the very beginning, precious few are willing to take a much-needed look at their sleeping habits and make the required readjustments to their schedules and habits. I strongly urge you not to be part of the majority in this regard…
Instead, take the following advice to heart.
Reestablish a Natural Rhythm by Optimizing Your Light Exposure
Part of living in accordance with your natural circadian rhythm is to have consistent, regular exposure to bright light during the day, and sleeping in absolute darkness at night.
This optimizes your natural melatonin production.
Unfortunately, while over-exposure to light in the evenings is typical, most of us are also under-exposed to light during the day! Most incandescent- and fluorescent lights emit very poor quality light, and what your body needs for optimal functioning is the full-spectrum light you get outdoors.
If you’re stuck in a windowless office for the majority of your day, using full spectrum light bulbs can help ameliorate this lack of high quality sunlight.
The reverse is true for the evenings. Ideally, once the sun sets, you’ll want to reduce the overall amount of light you’re exposed to. Here, using “low blue lights” can help. These light bulbs emit an amber light, opposed to the blue that suppresses melatonin production. Therefore, these bulbs are ideal for areas such as your living room, bedroom and bathroom.
TVs and computers also emit quite a bit of blue light, which will zap your melatonin if you work past dark, so ideally, you’d want to turn these items off once the sun goes down.
Once it’s time to sleep, make sure your bedroom is pitch black.
I strongly recommend installing blackout shades for this reason, or use thick drapes. Make sure all the lights are off in your room and that no light enters your room from other areas, such as night lights in your bathroom or hallway.
It’s important to realize that even a small amount of light, like that from a night light, or turning on the bathroom light to go to the restroom, can be enough to suppress your melatonin production for that night. So, if you have to get up, try to resist the temptation to turn on the light.
This may be a bit more than you are willing to invest, especially if you live in temporary circumstances. So what I have found that works really well is a high quality eye mask.
Fine-Tuning Your Sleeping Pattern for Optimal Health
Optimizing your light exposure as described above can go a long way toward reestablishing your natural circadian rhythm and a healthy sleeping pattern.
The next question then becomes, how much sleep do you need?
The right amount for you is based on your individual sleep requirements and not on a one-size-fits-all prescribed number of hours. That said, research has shown that, in general, chronically sleeping less than eight hours a night can have significant cumulative consequences. In short, your best bet is to listen to your body and adjust accordingly.
If you feel tired or sluggish upon waking or during the day, you’re likely not getting enough.
However, it would be very unusual for anyone to require less than six hours of sleep. The sweet spot is more likely between 7 and 8 hours. There are other variables though, such as the:
Number of times you awake at night
Time it takes to fall asleep
Percentage of your sleep at REM, and
Time spent in deep sleep.
Later this year I will be providing some articles that go into this topic more deeply.
Unfortunately, many people are quick to pop a pill once they start having sleep problems. But sleeping pills come with numerous side effects and can cause more harm than good. Better alternatives include using the Emotional Freedom Technique (EFT), listening to a brainwave synchronization tape, or trying a natural remedy that can help you relax without the side effects.
Summary of Key Points to Remember to Keep Your Body Clock Running Smoothly
It’s important to realize that even if you do everything else right – eat nutritious meals, exercise, manage stress – if you aren’t getting high-quality sleep your health is bound to suffer in any of the numerous ways mentioned above. So please, take your sleep seriously, and do your best to live your life in closer alignment with your circadian rhythm.
As a summary, the following guidelines can help to keep your circadian rhythm in its natural cycle:
Use full-spectrum light bulbs in your home and office during daytime hours.
Use “low blue lights” in areas where you spend most of your time in late evening, such as your living room, bedroom, and bathroom.
Turn off computers and electronic gadgets once the sun sets, and avoid watching TV late at night. Again, the blue light emitted from TV’s and computer screens mimic the blue light found in daytime sunlight, which can alter your melatonin production.
Sleep in total darkness! This is the “hidden” secret that most people tend to ignore, but which can dramatically improve the quality of your sleep. Personally, I sleep in a room that is so dark, it’s even pitch black at noon. Liberally use blackout shades and drapes to achieve this.
Sleep when it’s dark outside and get up when the sun comes up. At minimum, strive to sleep between 10 p.m. and 6 a.m. This means you should be in bed, with the lights out, by 10 p.m. and be up by 6 a.m.
Avoid working the night shift. It’s been linked to significantly lower levels of serotonin, which may cause sleep problems, anger, depression and anxiety. If you currently work the night shift, I would strongly suggest trying to switch your hours, or at the very least not keeping the night shift for longer than a couple of months at a time (and giving your body a chance to readjust in between).
For even more helpful guidance on how to improve your sleep, please review my 33 Secrets to a Good Night’s Sleep. If you’re even slightly sleep deprived I encourage you to implement some of these tips tonight, as high-quality sleep is one of the most important factors in your health and quality of life.
Mercola.com
