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Health and productivity effects of poor sleep

Health and productivity effects of poor sleep

Obvious symptoms of sleep deprivation constant yawning and the tendency to doze off when not active for a while; for example, when watching television, Grogginess when waking in the morning Sleepy grogginess experienced all day long (sleep inertia) Poor concentration and mood changes (more irritable).

Disease

Some of the physical effects found from long term fatigue are heart disease, diabetes, high blood pressure, gastrointestinal disorders and depression (Workplace health and safety QLD, 2008).  A study conducted by Andersen involving rats also showed sleep deprivation affects the expression of genes related to metabolic processes, response to stimulus and signalling pathways (Andersen et al, 2009). 

Numerous studies have shown that even a little bit of sleep deprivation decreases efficiency and increases risk of disease, including cardiovascular disease, cancer and diabetes.  Sleep deprivation has been shown to negatively affect endocrine (hormones) and metabolic functioning as well as nervous system balance (Nilsson, et al., 2004).  Sleep deprivation is associated with an increased concentration of cortisol plus other indicators of increased stress such as elevations in pulse rate, body temperature and adrenaline secretion (Vgontzas, et al.,1999).  Sleep deprivation also appears to increase blood concentrations of certain chemicals called cytokines and C-reactive proteins (Irwine, 2001 and Vgontzas, et al., 1998), indicating an inflammatory reaction.  The effect of unremitting low-grade inflammation may be to damage the inner walls of the arteries, which sometimes leads to vessel narrowing, high blood pressure, stroke, and heart disease (Irwine, 2001).  During truncated sleep, your heart might have to work harder, constricting blood vessels and increasing blood pressure even more, which could conceivably result in a heart attack or stroke (Martins, 2003). 

Sleep is as important to the human body as food and water, but most of us don’t get enough sleep.  Insufficient sleep or disruptions to the sleep contribute to adverse health effects. Numerous studies have also shown that even a little bit of sleep deprivation decreases efficiency and increases risk of disease, including cardiovascular disease. 

Initial changes to cardiovascular system from insomnia include hypertension, which is a potent co‑morbidity for other cardiovascular diseases. Hypertension has been linked to reduced sleep duration, with the highest correlation shown under 6 hours sleep per night (Gottlieb et al. 2006). However, associations have also been made between sleep of over 9 hours per night and hypertension and obesity. Furthermore this has not been supported at all in some studies and PPI in one older North American population actually showed a reduced risk of hypertension (Phillips, BOková and Enrigh, 2009.).

A study of 71,617 female health professionals found that sleeping fewer than five hours per night was associated with a 39 percent increase in the risk of coronary heart disease; even six hours per night showed an increase of 18 percent compared to sleeping eight hours per night (Najib, et al., 2003).  In an analysis of data on more than one million people, the levels of nearly all forms of death were two-and-a-half times higher for people who slept four hours or less compared to those who slept between seven and eight hours on average

A study of 71,617 female health professionals found that sleeping fewer than five hours per night was associated with a 39 percent increase in the risk of coronary heart disease; even six hours per night showed an increase of 18 percent compared to sleeping eight hours per night.  In an analysis of data on more than one million people, the levels of nearly all forms of death were two-and-a-half times higher for people who slept four hours or less compared to those who slept between seven and eight hours on average

Experimentally, sleep deprivation has been shown to negatively affect glucose metabolism and to enhance factors associated with Type 2 diabetes (Nilsson, et al., 2004).  Research has also shown that people who experience sleep disorders were as much as three times as likely to develop Type 2 diabetes (Kawakami, 2004).  Subjects in one study demonstrated impaired glucose tolerance for ten days after four hours of sleep deprivation (Spiegel, et al.,1999).  It is also found that sleep deprivation can play a role in obesity.  Sleep deficits bring about physiologic changes in the hormonal signals that promote hunger and, perhaps thereby, obesity (Spiegel, et al., 2004).  One study found that after two days of sleep curtailment the subjects had reduced levels of the fat-derived hormone leptin and increased levels of the stomach-derived hormone ghrelin.  These hormones are responsible for regulating hunger and appetite (Spiegel, et al., 2004).  These hormonal differences are likely to increase appetite, which could help explain the relative high BMI in short sleepers. 

 

Part 5 and more coming

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Essential Sleep (Part 2)

Essential Sleep (Part 2)

The benefits of sleep include:

Feeling rested;

Being physically and mentally alert;

Having more energy;

Making fewer mistakes (including causing accidents);

Feeling psychologically and emotionally recovered;

and to experience:

Improved cognitive function;

Improved memory;

Higher stress tolerance and resilience;

Increased productivity;

Normal body balance;

Healthier weight;

Reduced risk of CVD, diabetes and cancer;

Living longer; and

Feeling healthier. 

during sleep the mind is cataloguing our memories and deciding what to keep and what to throw away it is making memories stronger. It also seems to be reorganizing and restructuring memories.

It’s not possible to learn something new when you sleep, like a foreign language, but you can reinforce something you already know.One study found that students learned to play a series of musical notes better after listening to them during a 90-minute nap. The research shows that memory is strengthened for something you’ve already learned. Rather than learning something new in your sleep.

A review of studies on sleep found that we tend to hold on to the most emotional parts of our memories.

Getting enough sleep is associated with energy, joy, optimistic thinking and coping with negative emotions. 

Stages of Sleep                                                                           

Sleep Stage

Brain Waves

Common Characteristics

Frequency

Type

 

 

Stage 1

NREM

 

 

4 to 8

 

 

Alpha

& Theta

 

Transition between sleep and wakefulness

Eyes begin to roll and close

Consists of mostly theta waves with some brief periods of alpha waves (similar to waves of wakefulness)

Stage lasts 5-10 mins

 

 

 

Stage 2

NREM

 

 

8 to 15

 

 

Theta, Spindles,

k-complexes

 

Brain wave peaks become higher

Spontaneous periods of muscle tone mixed with periods of muscle relaxation

Heart rate  and temperature decrease

Stage last 5-10 mins

 

 

Stage 3

NREM

 

2 to 4

 

Delta, Theta

 

Deep Sleep or Delta sleep

Very slow brain waves

 

 

Stage 4

NREM

 

0.5 to 2

 

Delta, Theta

 

The last of deep sleep before REM begins.

Consist mostly of Delta waves

 

 

 

Stage 5

 REM

 

 

 

≥ 12

 

 

 

Beta

 

Beta waves have a high frequency and occur when the brain is active when asleep and awake.

Frequent bursts of rapid eye movement (REM) and muscle twitches.

Increase in heart and breathing rate

Vivid dreaming occurs here.

(Cook and Nendick, 2007)

Circadian Cycle

When a person falls asleep and wakes up is largely determined by their circadian rhythm, a day-night cycle of about 24 hours. Circadian rhythms greatly influence the timing, amount and quality of sleep (Lockley et al. 1997).

Literally hundreds of circadian rhythms have been identified in mammals (Campbell 1993). Among the numerous systems and functions mediated by the circadian timing system are, hormonal output, core body temperature and metabolism. The circadian clock is believed to sit in the suprachiasmatic nucleus (SCN) located in the hypothalamus of the brain. It was thought that processes now linked with circadian timing e.g. sleep wake cycles, were due solely to environmental cues, for example solar activity, it is now recognised however that these biological rhythms are regulated by factors inherent to the organism (Campbell 1993). A circadian rhythm displays a 24 hour cycle of wakefulness and sleep synchronised with the world’s night/day clock (Mansuy et al, 2003).  Everyone’s cycle will vary depending on behavioural and psychological factors (Mansuy et al, 2003).  The most typical pattern will be low alertness in the mornings as we wake, to highly alert mid afternoon (Swain et al, 2007).

The natural circadian rhythm in the body, which maintains a regular sleep-wake cycle, makes important contributions to physiological processes and psychological health. The normal rhythm is reset daily by the influence of bright light in the morning. Shift-workers, who may work at night and sleep in the daytime, and blind people may have difficulty maintaining a normal sleep-wake cycle because the natural environmental cues are miss-timed (Morris 1999). Studies show that shift work is one the greatest influencing factor causing an alteration in an individual’s cycle along with sleeping disorders (Baulk, 2008).  Altering the circadian cycle can lead to periods of decreased alertness leaving people extremely vulnerable to accidents and injuries (Andersen et al, 2009).

Our sleep patterns appear to be polyphasic. In one experiment, subjects were exposed to 14 hours of darkness; then they remained in a state of quiet rest for about two hours before falling asleep.  They then slept for four hours, awakened from a dream, spent another two-hour period in quiet rest, and then fell asleep again for four hours more.  The subjects awoke at 6 a.m. each morning from their dream sleep and then spent two hours in quiet rest before arising at 8 a.m.  These subjects followed their own natural rhythms, sleeping for eight hours with blocks of time at quiet rest (Wehr, S.E, 1996).  This polyphasic sleep appears to be a pattern in many mammals.  We experience hypnagogic imagery – a state described as dreaming, drowsy, floating, wandering – every night just before we fall asleep.  Every night before we go to sleep we spend a few minutes in a state of relaxed wakefulness characterised by drifting thoughts and alpha brainwaves.

Another interesting method for lessening the impact of sleep deprivation was through a study that found there were certain hours better to sleep through the night. A new Stanford University study on the science of sleep deprivation suggests that early­ morning sleep is more restful than a middle‑of‑the‑night nap. In a study of two groups of men they found that early‑morning sleepers scored higher on wakefulness tests and on measures of sleep efficiency. (Stratton, 2003) Although this study shows that there may some advantages to when you get your sleep it is more an avoidance of the problem rather than a solution.

We are also influenced not just by sleep but also our perceptions of its quality. If we think we’ve had a wonderful sleep last night, we feel and perform better, even if our sleep was actually the same as usual. In this study researchers randomly told some people they’d had better sleep than others after they were hooked up to some placebo brain sensors). When they were given a cognitive test the next day, those who’d been told they slept the best also did the best in the test.

 

Part 3 and more coming

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Why We Overeat?

Why We Overeat?

I had a friend a long time ago that used to seesaw with her weight many times over the year. Whenever she got depressed or upset she would eat a lot of rich, high calorie foods that gave her some instant pleasure. Her favourites were chocolate, and Milo by the spoonful, straight from the can. Despite her reasons for binge eating, it didn’t bring any happiness and in fact contributed significantly to her problem. We need to deal with the beliefs that underlie the undesirable eating patterns as part of any dietary program.

Examining emotions and habits during a weight loss journey gives an insight as to why people overeat or have a hard time maintaining weight after losing it. The reasons given for overeating and excess weight gain often have similar root causes including boredom, emotional instability, and stress. Some of these I have already covered but the potential list is pretty long.

The major reasons for overeating include and our appetite includes

  • Busyness
  • Time of day (energy levels)
  • Mood
  • Nervous
  • Stress
  • bored
  • low self esteem
  • hormonal
  • hunger
  • peer/social pressure
  • routine/habit
  • media and advertising
  • low price/convenient
  • mental stimulation
  • too busy
  • Feeling Unloved
  • Anxious or restless
  • Happy
  • Angry or jealous
  • Tired
  • Dissapointed or rejected
  • Depressed
  • Emotional
  • Availability

Or if there are real food cravings, it may require some mineral or nutritional supplementation. For example, some sugar cravings can be significantly reduced with chromium or vanadium supplementation. Sometimes more protein-rich foods need to be eaten.

Lets look at some of the main ones

Busyness and stress are often the underlying factors why we put on weight. One way or another it prevents us from doing what we need and know we should be doing. Too busy to exercise, to busy to eat right or buy the right food, too busy to take the time for ourselves, too busy. Woman are often so busy with looking after the family they constantly justify another little treat and poor eating to get them through another day. While both men and woman often become too busy around their careers. Taking a bit more time for ourselves and focusing on our health and healthy eating can make a big difference to our lives.

Emotional weight gain can be a major problem. Hence why any weight control program needs a lot of emotional support. To much weight on the mind can put on weight in the body. In a study of eating disorders in girls in the 7th to 10th grades, which also applies to us as we age, many of them reported an inability to distinguish between emotional feelings and hunger.  Some of these girls were unable to distinguish between scared, angry and hungry and are able to lump all of these conditions together, which leaves them to overeat whenever they have an emotional feeling.  This is no wonder if you look at how we use foods as rewards and distracters as we grow up. Often when we are feeling upset or anxious we use food as a substitute.

Energy lows can be a major appetite trigger, either directly or indirectly is the amount of energy you have. If you understand your daily energy cycles you can avoid many food cravings and not confuse your levels of energy with poor eating habits. Remember, they are just habits. Most binge eating for example occurs in the low energy times of late afternoon and late evening when energy levels are low. At this low energy time you are also more likely to feel in a low mood so the food further acts as an energy catalyst to get you out of that mood. Only the solution is only a short-term mood changer and often has a negative energy and emotional rebound effect. In support of this one study of dieters found that the average time at which relapse occurred was late afternoon at 4.34 pm, about 4 hours after their last meal when they were moderately hungry and their energy levels were low. The majority of cases for temptation and relapse were characterised by upset including anger and by depression or tiredness.

On the other side of the coin research is increasingly showing that how we feel is also affected by what we eat. Research shows links between depression and nutritional deficiencies.  The research also shows that the deficiencies do not have to be excessive to depress the mood. So it can become a vicious circle of food-mood-food. Dieting and food restriction can also play havoc with our moods. In a review of dieters the research concluded that negative moods particularly depression increased eating amongst the dieters. In another study of people who were at least 30% over-weight and ate only a fasting supplement of 420 calories per day over a 10 week period, they most commonly violated their diets in the second month at a time when they were feeling fatigued. Using brain imaging machine when you fast or deprive yourself of food (as in a diet), your brain sees high calorie foods as being far more pleasurable. The cravings and temptation to eat unhealthily, will be far more intense. This is what they found in the short term, at least. It appears The orbifrontal cortex is responsible for how the brain perceives the “value” of a food—or how pleasurable it will be to eat.

There is no doubt the negative effects of low moods and energy have on weight management. For many people when these two are low up goes the weight. Fortunately, for the majority of people, physical activity is the most effective way to raise energy and reduce tension. It produces rapid and reliable results that can change moods immediately. Overwhelming scientific evidence shows that even moderate physical activity has the ability to increase your energy, unlike the energy drinks which actually make you feel more drained. In an experiment where one group was exercising by walking and a control group sat quietly reading over materials there was a significant change in mood that was significant and unmistakable with the walking group. Research has highlighted that 15 minutes of walking produces slightly more energy than 5 minutes but even 5 minutes of brisk walking has a significant effect. After just a 10 minute brisk walk there were still statistically significant effects 60 minutes later and 120 minutes later a week energy increase was still evident. A brisk walk therefore energises the person for somewhere between 30 to 90 minutes afterward.

In a study on unhealthy snacking researchers identified six distinct motives for snaking including opportunity induced eating, coping with negative emotions, enjoying a special occasion, rewarding oneself, social pressure, and gaining energy. Sound familiar? While Enjoying a special occasion and opportunity induced eating were most important. For all reasons except to enjoy a special occasion, younger people reported a higher score. Women indicated a higher score than men on coping with negative emotions, enjoying a special occasion and gaining energy. People who diet to a stronger extent reported a higher score for snacking because of social pressure, to reward oneself and to cope with negative emotions, with the latter also being related to a higher BMI.

Other studies have also made a link between emotions and snacking. One study showed movie-goers watching tearjerkers ate between 28% and 55% more popcorn both in the lab and in a mall theatre. Previous studies have shown that humans who play violent video games show clear signs of distress (ie, negative stress), comprising higher blood pressure as well as reports of less fullness and a tendency to prefer sweet food. Studies suggest that watching scenes of an action movie may cause distress, a condition that can increase food intake in the absence of hunger. One study found action and adventure movies also lead television viewers to eat more calories – but only if the foods are within arm’s reach. With action movies, people seem to eat to the pace of the movie. In contrast, watching an engaging comedy clip has been linked with decreasing tiredness, sadness, irritation, anxiety, and restlessness, while increasing relaxation and joy. Thus, watching a comedy clip may cause eustress (ie, positive stress), which, owing to its high rewarding property, may reduce an individual’s concomitant drive to eat. While another study found that female students ate less grams when watching a comedy program compared with food intake when watching a television (TV) documentary.

Our eyes lie

Another major factor in overeating is the supersize me phenomena. Portion size is a key environmental driver of energy intake, and larger-than-appropriate portion sizes increase the risk of weight gain. Unfortunately the size of food packaging and portions has steadily increased over the past 30 years and these super sized food portions play a major role in weight gain. Simply people who sit down with bigger portion sizes of food are more likely to be overweight and obese while those who maintain a small portion size lower their weight. Whether it is from our parents telling us to eat all our food on the plate or our hunter-gatherer starvation mentality once it is on our plate we tend to eat it and as a result over eat. For instance, one study reported that 54% of American adults generally claim that they attempt to eat until they “clean their plates”. Interestingly very early studies showed this when participants who drank soup through a tube drank less when they had visual contact with the soup than when they did not. Literally a person's eyes may influence how much they consume, leading them to be less influenced by physiological cues of satiation. As a result, their estimate of how much they have consumed and how full they are may have to do more with what they believe they saw themselves eat and less with how much they actually ate. In a study of fifty-one men and women were served lunch of different portion sizes subjects consumed 30% more energy (676 kJ) when offered the largest portion than when offered the smallest portion. Larger portions led to greater energy intake regardless of serving method and subject characteristics. In one study after a 3 month intervention subjects who regulated their portion size had a greater weight change from baseline to the end of the 3-month intervention period loosing 3.7 kg compared to 0.1 kg in the control group showing that portion control is effective to reduce body weight in overweight and obese diabetic subjects.

It is time to have a think on why we overeat and puts some steps in place. Simple strategies like keeping a food mood diary can help you identify any common factors in overeating. While serving food on small plates can make a big difference to how much you eat each meal. Time to downsize our meal sizes.

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