Circadian Rhythm

Proven: Shift Work is Detrimental to Your Health

Modern society has become almost “timeless” due to electric lighting and other technology. We can buy groceries at midnight, get medical care at any hour, and access 24/7 customer service for any problems that arise during the day or night. There are definite benefits to this constant access. However, there may be serious health consequences for the people who keep our world running around the clock.

Shift Work and the Circadian Rhythm

The main problem with shift work is that the timing of sleep matters. Our bodies are made to run by internal clocks that are set by light levels. When our retinas sense light, they pass signals to the suprachiasmatic nucleus (SCN) to shut down the production of melatonin and other biochemicals associated with sleep. Our circadian rhythm is also affected by factors such as temperature and the timing of meals.

How does shift work affect the circadian rhythm? People who work odd hours often must function at times when their bodies are telling them to settle into bed so key restorative processes can occur. They must try to sleep at times when cortisol and other hormones that encourage wakefulness are high. People who engage in shift work suffer from a long-term form of jet lag, in which their internal clocks are not aligned with their lifestyle.

The Out-of-Sync Brain

What happens to the human body when shift work forces the circadian rhythm out of sync with the environment? Researchers have discovered a variety of effects. Anyone who has lost a night of sleep knows the short-term effects. People feel more fatigued and suffer from “fuzzy” thinking, but the effects on cognition do not stop there. Chronobiology research has found that people who engage in shift work perform lower on cognitive tests, with the effects lasting up to five years after they resume a typical day schedule. Medical staff who work nights are more likely to miss critical issues and often struggle to stay awake, much less to perform to a high standard of care. However, the effects of shift work extend beyond mood and mental function. There appear to be long-term effects on disease risk and lifespan as well.

Can Shift Work Affect Your Long-Term Health?

New research suggests that cardiovascular health is one of the areas most effected by shift work. Deep sleep allows our hearts to rest and to perform cell repair as well as other restorative processes. Without adequate sleep, people have higher blood levels of stress hormones and increased heart rates. The result is an increased risk of cardiovascular disease that can ultimately be life-threatening.

In addition, people who work odd shifts have a higher risk of stroke and experience more devastating strokes when they do occur. Lab rats who have a disrupted circadian rhythm are more likely to have lasting brain damage and loss of limb function after a stroke.

Disproportionately Severe Effects on Women

Shift work increases risk factors for chronic disease across the board, but the exact effects appear to depend a great deal on biological sex. While men are at higher risk of permanent disability from a stroke, women get the short end of the stick overall. A study of nurses found that women who work night shifts see more negative effects on their heart health than males, even when adjusted for lifestyle and risk factors. They have a higher incidence of coronary artery disease, heart attack and death from heart problems. This increase in risk is significant, at about 15 to 18 percent higher.

Why do men and women suffer different health consequences from shift work? It appears that male and female bodies react different to disruptions in the circadian rhythm. A study of sleep-deprived volunteers of both sexes found that women have more changes in mood and cognitive performance than men when subjected to a disrupted internal clock. This may pose a challenge to the public health as many jobs involving shift work, such as nursing and waitressing, are traditionally female professions.

Our society requires 24-hour staffing in many fields to accommodate modern lifestyles. However, this does not come without consequences for the workers involved. While we will always need medical and law enforcement staff around the clock, it may be better for public health to allow workers in less time-sensitive industries to go home in the evening and get the good night of sleep that they need for optimal health.

Digital Detox: How Unplugging Can Recharge Your Batteries & Reset Your Circadian Rhythm

Jun 22 by Ewcopywriting Leave a Comment

Electronic devices have allowed us to be more connected, yet more detached. Smartphones, tablets and other devices give us access to information, social media and email 24 hours a day. While this should make it easier to manage our lives and maintain meaningful connections, it appears to actually be hindering us in these areas. New research suggests that taking a periodic digital detox may be the answer.

The Downside of the Digital Life

There is no question about it: Most modern people depend on their digital devices. We stay connected to friends and family on Facebook, collaborate on work projects online, and entertain ourselves with Netflix or ebooks. There are benefits to having this constant access: We can handle work emergencies with a few swipes on the phone and be reached in seconds should an emergency occur.

However, there are downsides to this arrangement as well. Many people are invisibly chained to their devices. The blue light from electronic devices is now known to disrupt the circadian rhythm and delay sleep onset. Smartphone use has been linked to the steady rise in sleep disorders, which now affect almost half of American adults. Constantly using devices makes us less empathetic and hinders our ability to communicate effectively. It may even increase narcissism. Researchers have identified that constant technology use can cause mild attention deficits and a lack of critical thinking, a condition dubbed “monkey brain syndrome.” It seems that constant access to technology may be a threat to both public and individual health. What is the answer?

What Happens When We Unplug?

New research suggests that unplugging from technology may be good for our physical, emotional and social health. In a recent study, researchers took a group of people to Morocco. They spent the first night socializing in a hotel with full access to their devices. After this, they were taken to the desert and stripped of their digital access. The results were surprising. Not only did these research subjects build deeper friendships and have higher-quality interactions, but they also had better posture, felt more rested despite the same amount of sleep and were able to develop more creative solutions to their problems.

Is it time for Americans and Europeans to throw away their smartphones and devices? Unfortunately, this is not possible in the modern world. However, taking a few device-free days occasionally, known informally as a “digital detox,” may be beneficial. Being online regularly throughout the day and night actually depletes nutrient stores in critical areas of our brains. It only takes a few days to rebuild these stores and undo the damage of constant screen use.

Options for Digital Detox

Modern people do not need to attend an expensive digital detox retreat to unplug for a few days. If you want to give your mind a rest from the online rat race, plan for a weekend offline. Notify coworkers, friends, and family ahead of time that you will not be reachable for a set time period and plan a few days of relaxation and fun. At the end of the detox, experts recommend that you give serious consideration to how you re-enter the digital world. Can you cut back on the amount of time you spend on devices? Which apps improve your life and which make it more stressful? Once you have traded your “monkey brain” for a more human one, it will be easier to critically analyze how media affects your existence.

There is no question about it: Modern life demands that most people have a certain amount of screen time and digital access. However, we can use these things in moderation rather than letting them rule our lives and cause neurological disruption. Putting phones and other devices away for a few days may be just what the doctor ordered. Modern technology is supposed to make our lives easier rather than more difficult.

What You Eat Is Intricately Linked to Sleep Timing, Quality and Duration

Jun 17 by Ewcopywriting Leave a Comment

How do your food choices affect your sleep? If you’ve ever reached for a cup of chamomile tea or a glass of warm milk before bed, you probably have some idea. Although there has not been solid evidence that diet affects sleep until recently, many people in cultures around the globe maintain deeply-held beliefs that some foods and beverages can either help or hinder slumber. New studies linking dietary habits and sleep habits are showing that sleep and diet are indeed interconnected, although we may be wrong about which foods are the best choices.

How Diet Affects Sleep

People have long been advised to avoid spicy and fatty foods before bed to prevent a sleepless night of heartburn, but research suggests that diet affects sleep in other ways. A recent study looking at the relationship between sleep and eating habits found interesting connections. According to the study, people who sleep well at night are likely to take in less caffeine (not surprisingly) as well as less of an amino acid called choline, which is found in eggs and meat. On the other hand, those who sleep only for a very short duration tend to drink less water and eat fewer brightly-colored vegetables.

There appear to be many variables involved in the diet-sleep connection. Researchers have yet to figure out a “Golden Mean” in nutrients that allows for optimal sleep, but the evidence is clear: Diet and sleep habits are deeply and intrinsically linked. What you eat, and when you eat it, can make you fall asleep later, wake up more often, and even reduce the quality of sleep for the duration of the night. However, this is not the only link between diet and sleep.

A Reciprocal Connection

Evidence suggests that not only does diet affect sleep duration, but that sleep can affect diet as well. For night owls, the propensity may be to go to bed late and sleep late; However, our modern schedules don’t often allow for this. As a result, night owls may try to make up for lost hours by sleeping in late whenever possible. Yet ,research shows that people who sleep late are more likely to eat fast food and other foods high in carbs and fat. This may be due to convenience, as people who are often tired are less likely to have the energy to prepare a healthy meal. Additionally, people are generally more impulsive and have less ability to make good decisions when sleep-deprived. A lack of set routines may also be an issue, as people who do not wake and eat at set times are more likely to eat less-healthy meals.

An unhealthy diet can also affect sleep by contributing to obesity. People who have a high body mass index (BMI) show slightly different sleep behaviors than those who maintain a healthy weight. For those with a high BMI, the nightly balance of different stages of sleep is altered in ways that can affect rest and regeneration. This can affect the quality of their sleep and how much energy they have upon waking. For instance, overweight people get less stage 2 sleep and a higher proportion of REM sleep. In addition, people with a high body mass index are at higher risk of sleep apnea and other disorders that can affect sleep quality.

Weight, Diet, and Sleep: The Proverbial Chicken and Egg

Which came first: the high-fat diet or the irregular sleep schedule? This is still unclear, but will likely be the subject of future studies. While obesity is known to cause sleep disorders, sleep disorders are also known to negatively affect the metabolic system. The result is a downward spiral in which people sleep poorly, make poor health decisions that lead to weight gain and suffer even more disordered sleep. While it can be difficult to break this cycle and get your health back on track, it is nonetheless important to your health to do so.

So what should you be eating if you want to sleep soundly at night? Although there is increasing evidence that diet affects sleep, and vice versa, the exact nature of the connection is not fully understood. While revolutionary new insights have been gained as to how when and what you eat affects your metabolism, researchers have yet to discover the exact diet that encourages good sleep. For now, doctors continue to make the general recommendation that people try to attain and stay at a healthy weight by getting plenty of sleep and eating a varied, healthy diet.

New Research Uncovers Previously-Unknown Effects of Blue Light on Sleep

Jun 15 by Ewcopywriting Leave a Comment

If you’ve been keeping up with recent research, you’re probably aware of the negative effects of blue light from electronic devices on sleep. More and more we are being warned to put down the smartphone and power down the laptop at night. The link between low melatonin levels and blue light is well established. However, blue light may be affecting us in more ways than we previously realized.

Light, Melatonin and Sleep

Throughout human history, people have gone to bed shortly after dark. Our bodies are biochemically primed for this behavior. When our retinas stop sensing light, they send a message to the suprachiasmatic nucleus (SCN) of the hypothalamus. This part of the brain functions as the timer for our internal clocks, setting off a cascade of events that prepare us for sleep. One of the main ways this happens is through the release of melatonin in the pineal gland. Conversely, in the early morning hours when light first appears, melatonin production is shut down. At this time, our bodies switch to making cortisol and other hormones that increase alertness.

Realistically, a day in modern life does not end at sundown. We are exposed to artificial lighting from a variety of sources including light bulbs, televisions, computers and smartphones. Although even dim artificial light can affect melatonin production, it appears that the effects of blue light, such as that emitted from devices like tablets and smartphones, may be even greater.

More Than Melatonin: The Problem With Blue Light

Blue light is constantly present in our world. How many people go to bed with an e-reader, tablet, or smartphone in hand? This can have an immense impact on how long it takes us to fall asleep, as well as the quality of our sleep. Human eyes have special wavelength-sensitive photoreceptors that sense blue light, which appear to shut down melatonin production more effectively than other kinds of receptors in the eye.

Mice also have a circadian rhythm, although it is the opposite of ours. Mice are nocturnal and sleep mainly throughout the day, which means they are primed to produce melatonin and fall asleep in the presence of light. Although they have a very different reaction to light than humans, they have the same receptors for blue light in their retinas. When exposed to light, mice in a recent experiment became sleepy as expected. However, when exposed solely to blue light, these mice became more active and took much longer to fall asleep. This did not occur in mice who were bred to lack the blue-light photoreceptors.

Interestingly, blue light appeared to delay their sleep as much as it does in humans, having more of an effect than green and violet light. Scientists behind these studies believe this is because blue light may also increase levels of stress hormones like cortisol. These hormones are cues for wakefulness, explaining the wakening effects of blue light on both diurnal and nocturnal animals.

Blue Light: A Possible Cause of Circadian Rhythm Disruption

While blue light is present in sunlight, it is present in far lower amounts than that seen in electronic devices. Sunlight contains the full spectrum of light, which is why it can be refracted into a rainbow. On the other hand, most devices contain almost exclusively blue wavelengths of light. Given that blue light reduces melatonin production and may even increase cortisol levels, this has immense implications for human health.

Sleep disorders are on the rise in the United States; increasing blue light levels in our environment that inhibit melatonin production and increase stress hormone levels may be part of the cause. However, many people are tied to their devices. We use smartphones and tablets to perform work, to communicate with friends, even to read a book. Can modern people find a balance that allows them to get the sleep they need? This is the question for chronobiology researchers and other scientists who study circadian rhythm.

Owl or Lark? How Your Preferred Bedtime Affects Your Health

Jun 11 by Ewcopywriting Leave a Comment

Benjamin Franklin once observed, “Early to bed and early to rise makes a man healthy, wealthy and wise.” However, in reality, it may not be so simple. While some people are up with dawn and yawning by dusk, others come alive at night, yet struggle to function in the mornings. New research has found that whether you are a “morning lark” or a “night owl” is determined by your genes. How you manage your chronotype and your lifestyle can have far-reaching effects on your health.

What Are Chronotypes?

Your chronotype is generally set by your sleep midpoint. For instance, a person who naturally goes to sleep at midnight and wakes up at 8 a.m. will have a midpoint of 4 a.m., making them a natural night owl. People who go to sleep early and wake early naturally are morning larks.

Our internal clocks shift slightly during our lives. Most small children are naturally morning larks, as many bleary-eyed parents have observed. However, this schedule has shifted by adolescence. Adolescents and young adults naturally lean toward a later bedtime and sleeping in well past dawn. On the other hand, the elderly move back to an early bedtime. However, there is variation even within this general pattern. For example, some toddlers are consistently up at 4 a.m. while others “sleep in” until 7 a.m.

Society has classically viewed night owls as lazy. These people struggle to get up and off to work or school early in the morning and are often not on the job during their most productive hours of the day. This may make them appear lazier, when in fact they are suffering from a phenomenon known as social jet lag, or a mismatch between outside obligations and internal rhythms. New research suggests that the difference between night owls and morning larks is not based on motivation and morality, but rather on genetics.

What Determines Your Chronotype?

Scientists have discovered that different chronotypes have measurably different levels of proteins associated with the circadian rhythm and even different variants of genes associated with the sleep-wake cycle. In a recent chronobiology study, a group of people with varying chronotypes were tested for salivary levels of melatonin and expression of the circadian rhythm genes Per1, Per2, and Rev-erbα. Researchers found that night owls had later expression of melatonin than morning larks, which means these people were biochemically primed to sleep and wake at different times. Considering that a person’s amount and quality of sleep can have immense effects on both lifestyle and health, this can affect a natural night owl’s life in a variety of ways.

Marching to the Beat of Your Internal Clock

Ideally, people would be able to work and go to school at the times when they are primed to be productive. They would also be able to sleep when they are biologically intended to do so. However, this is not the case for many modern people. Many night owls are crawling out of bed in the morning far before their sleep cycles have completed; many morning larks are forced to be awake past their natural bedtime for various obligations. The result is not just a society of sleepy people, but one of unhealthy people. Living out-of-sync with your chronotype can have a variety of health consequences.

The Health Risks of Ignoring Your Circadian Rhythm

What, exactly, happens when people are forced to live out of sync with their chronotype? As researcher Frank Scheer noted in the Proceedings of the National Academy of Sciences, this can cause “a decrease in leptin, increase in glucose and insulin, increase in mean arterial blood pressure and reduced sleep efficiency.” This leads to an increased risk of metabolic syndrome, cardiovascular disease and a variety of health disorders.

However, night owls do not necessarily need to suffer from diseases associated with circadian rhythm disorders. When allowed to change their schedule to match their natural sleep-wake cycles, people suffer no additional health risks. Being a night owl is not in itself unhealthy unless you try to act like a morning lark.

Our work and other activities were once limited to the hours when there is natural light. However, modern technology and artificial lighting allow us to be productive at any time. Allowing night owls and morning larks to work and learn when they are primed to be so may not just create a more productive workforce, but a healthier one as well.

Researchers Discover How Coffee Affects the Circadian Rhythm

Jun 03 by Ewcopywriting Leave a Comment

Coffee is an American obsession. While many people enjoy this energizing beverage, many of us also view it as a bad habit, even if a minor one. However, a new chronobiology study on coffee and the circadian rhythm has found that moderate amounts of coffee affect the circadian rhythm in positive ways, and may be especially good when it comes to regulating your sleep-wake cycle.

How Coffee Affects the Circadian Rhythm: Turning Back the Clock

Many of the studies looking at the effects of caffeine on the circadian rhythm have been performed on lab animals rather than humans. Recently, researchers decided to definitively nail down exactly how caffeine affects the circadian rhythm by studying the effects of this stimulant on both live humans and human cells in-vitro.

In a human study, four groups of people were subjected to one of four treatments shortly before going to bed. The first group was exposed to bright light and given a double-espresso strength dose of caffeine. The second group was exposed to dim light and given a double-espresso dose of caffeine. The two other groups were both exposed to bright or dim light but were given a placebo pill. The result? Not only did the caffeine keep participants awake at night, but it completely shifted their circadian rhythm so they produced sleep hormones and fell asleep an average of 40 minutes later—nearly half the magnitude of delay caused by bright light. In short, coffee appears to delay the circadian clock by about 40 minutes, about half as long as does exposure to bright light.

When human cells in Petri dishes were treated with caffeine, the same effect was observed. Researchers found that coffee affects the circadian rhythm in human cells in-vitro by activating adenosine receptors, which are important regulators of internal clocks. In effect, the clocks were held back.

Of Mice and Metabolism: Caffeine and Metabolic Markers

This is not the first study that has found coffee can have powerful effects on internal clocks and metabolism. In prior research, mice were exposed to caffeine. Half of the mice were allowed to eat whenever they wanted while half had restricted feeding times. It was shown that caffeine restricted the gene expression and thus production of inflammatory factors and metabolic markers associated with cancer in the intestines of both groups. In the group allowed to eat freely, it also restricted these factors in the liver. Interestingly, coffee affects the circadian rhythm of different cells in different ways.

A Cure for Jet Lag?

What does this mean for human health? First, caffeine may be used in the future to modify the activity of circadian clocks. This could help in the treatment of jet lag, non-24 hour circadian rhythm disorders and several other sleep disorders. However, caffeine alone appears to have less effect on the liver and possibly other organs with their own internal clock mechanisms. In essence, we may be able to use our new knowledge about how caffeine affects the circadian rhythm to cure jet lag in the brain, but jet lag in the liver will remain an issue. In other words, some organs will still remain in their own time zone.

This research also has potential consequences for people who enjoy a cup of coffee after dinner or otherwise take in caffeine at night. By doing so, you may be delaying your internal clocks and interfering with sleep more than previously believed. Even if you can easily fall asleep after a cup of coffee, your internal clocks have still been altered. A substance that is beneficial to people trying to reset internal clocks may not be beneficial to others.

Because caffeinated beverages are so popular in the United States, it is important to understand how coffee affects the circadian rhythm and other aspects of health. It appears that caffeine can be extremely beneficial in people who need to modify their internal clocks slightly, but that it could have unwanted effects in others who drink it before bed. In short, if you are looking for a warm beverage to enjoy after dinner, unless you’re trying to adjust your circadian rhythms, you may want to reach for the herbal tea.