Dr Dingle's Blog / IQ

Essential Sleep (Part 6). Cognitive decine and the brain

Essential Sleep (Part 6). Cognitive decine and the brain

Late night

Research on 59 participants, those who were confirmed night owls (preferring late to bed and late to rise) had lower integrity of the white matter in various areas of the brain (Rosenberg et al 2014). Lower integrity in these areas has been linked to depression and cognitive instability.

 

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Essential Sleep (Part 5). Sleep and weight gain

Essential Sleep (Part 5). Sleep and weight gain

Sleep and weight

Obesity in another disorder linked with insomnia. Research shows that diets that are higher in saturated fats are more susceptible to chronic diseases and disorders which includes insomnia (Novak et al. 1995). This is an alarming fact as 20% of the population of the United States of American are overweight or obese (Patterson et al. 2004).

Many studies, including one spanning twenty years, have tested the hypothesis that sleep and obesity are linked and the majority of results show positive correlations (Gangwisch et al. 2005). Further studies, with over 500,000 total participants via meta‑analysis have supported obesity and insomnia in adults and children (Cappuccio et al. 2008). The trends of increasing BMI and reduced sleep hours appear to go hand in hand, along with sleeping troubles related to Sleep Apnoea often seen in obese patients.

This link between Obesity and the symptoms of its associated diseases demonstrates a common trend towards diminishing an individual’s peak performance. Obesity and many of the health conditions which result from it increase the lower productivity levels associated with lower mental and cognitive functioning.

Obesity is also a serious factor in poor sleep habits. In a number of studies obesity was associated with "reduced sleeping hours " (Ko et al (2007). Obesity, particularly abdominal and upper body obesity, is the most significant risk factor for Obstructive Sleep Apnea (OSA). Patients with sleep apnea often experience daytime sleepiness and difficulty concentrating (Teran-Santos et al, 1999). Studies have also shown a strong association between sleep apnea and the risk of traffic accidents (Terán-Santos et al (1999).  In fact, subjects suffering from sleep apnea were at a higher risk than those who had consumed alcohol to be involved in a traffic accident. This has major implications, particularly for overweight and obese workers using any form of equipment of driving vehicles.

This lack in sleep will then leave the employee going to the work already feeling tired, irritable and stressed, therefore making it difficult to concentrate, and highly increasing the chances of being injured or making a mistake which may put fellow workmates in danger (Lynch, 2005) It is situations like this, where the worker comes to work already feeling tired, that the employee is putting his safety and other's safety at risk.

Shift workers are known to be a high-risk group for obesity. In the current study population, rotating-shift workers showed a higher distribution of the highest body mass index compared with daytime workers

In a study of the brains of 24 participants after both a good and a bad night’s sleep. after disturbed sleep, there was increased activity in the depths of the brain, areas which are generally associated with rewards and automatic behaviour. It seems a lack of sleep robs people of their self-control and so their good intentions are quickly forgotten.

What we have discovered is that high-level brain regions required for complex judgments and decisions become blunted by a lack of sleep, while more primal brain structures that control motivation and desire are amplified.”

In other words: lack of sleep robs people of their self-control and so their good intentions are quickly forgotten.

On top of this, the researchers found that after being deprived of sleep, participants displayed greater craving for high-calorie junk food. The more sleep-deprived they were, the greater the cravings. A stufy of 13,284 teenagers found that those who slept poorly also made poor decisions about food. Similarly, a Swedish study found that at a buffet, tired people were more likely to load up their plates.

The link has even been made from poor sleep through to food shopping. A Swedish study found that men who were sleep-deprived bought, on average, 9% more calories than those who’d had a good night’s sleep. These results were likely the result of the poor decision-making. It had been thought that the tendency to eat more after poor sleep was related to the so-called ‘hunger hormone’ ghrelin. But the latest studies suggest that it’s simple self-control that is most important in causing the sleep-deprived to over-indulge.

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Essential Sleep (Part 3)

Essential Sleep (Part 3)

Sleep problems

Many sleep problems but by far the biggest is sleep deprivation and poor sleep. However too much sleep can also be a problem. Over sleeping may also be a problem. In one study sleeping 10 hours or more also increased the mortality rates by one and a half times.

 Sleep Deprivation

Sleep is as important to the human body as food and water, but most of us don't get enough sleep. Dysoninia (poor sleep) related sleep disorders alone are broken into Intrinsic, Extrinsic and Circadian‑Rhythm sleep disorders including disorders such as but not limited to: "Psychophysiologic Insomnia, Sleep State Misperception Idiopathic Insomnia, Narcolepsy, Recurrent Hypersomnia, Idiopathic Hypersomnia...Restless Legs Syndrome & Intrinsic Sleep Disorder NOS" (MSM, 2001, pp. 27).

Risk factors for sleep related illness are diet, lifestyle, occupation, stress and grief, amongst many others (Helmanis, 2006 pp. 24‑25).

Almost 90 per cent of Australians suffer from some type sleep disorder at some stage of their lives. Of these, 30 per cent suffer from severe sleep disorders. Very few people regularly enjoy the amount, or quality of sleep that they need. The estimated economic costs to the country from this are between 3 and 7 billion dollars annually. There are also huge, unmeasured physical, psychological, emotional and social costs.

Insomnia

Causative factors for insomnia may be multifaceted but generally include some psycho physiologic hyperarousal or emotional distress. Other precursors may be pain, movement disorders, psychiatric disorders, circadium rhythm dysfunction, medication and substance abuse (Billiard and Bentley, 2004). In some cases, the risk of insomnia is subject to a genetic bias. However, specific physiologic indicators for the familial influence have not been fully identified (Parkes and Lock, 2009).

 Insomnia is the difficulty initiating or maintaining sleep or both resulting in inadequate quality or quantity of sleep (Tomoda et al, 2009). Insomnia can manifest itself by many symptoms from not being able to sleep at normal hours and low quality and quantity of sleep to sleeping but not finding it refreshing. Other symptoms may include daytime sleepiness, frequent waking, early morning waking and difficulty retuning to sleep (Cureresearch.com, 2005).

Most adults have experienced insomnia or sleeplessness at one time or another in their lives (Straker, 2008). It is estimated that insomnia effects around 30-50% of the general population with 10% experiencing chronic insomnia (Straker, 2008). It has been estimated that in the US that 70 million people suffer sleep problems, and of these, 30 million suffer chronic insomnia (Stahura and Martin, 2006). Recently a survey showed that 1046 of the 2000 adults surveyed experience at least one night of lost sleep due to insomnia symptoms; the survey also concluded that insomnia is a growing issue of concern (Goolsby, 2006).

Insomnia generally affects women more than men and the incidence rate tends to increase with age (Straker, 2008).

There is a clear correlation of age to insomnia (Curless et a!. 1993). A number of surveys have reported between 28% and 64% of post menopausal women suffer from insomnia (Hachul de Campos et al. 2006).

Insomnia can be classified into three categories transient, short-term and chronic insomnia (Tomoda et al, 2009). Transient insomnia are symptoms lasting less than one week, short term insomnia are symptoms lasting between one-three weeks and chronic insomnia are those symptoms lasting longer than three weeks (Tomoda, 2009).

Narcolepsy

Narcolepsy is a sleep disorder that causes overwhelming and severe day time sleepiness (Retsas et al, 2000). Pathologic sleepiness is characterised by the fact that it occurs at inappropriate times and places (Retsas et al, 2000). These daytime sleep attacks may occur with or without warning and can occur repeatedly in a single day (Edgar et al, 2006). People who suffer from Narcolepsy often have fragmented night time sleep with frequent brief awakenings (Edgar et al, 2006).

Narcolepsy is typically characterised by the following four symptoms:

Excessive daytime sleepiness (90%)

Cataplexy: A sudden and temporary loss of muscle tone often triggered by emotions such as laughter. (75%)

Hallucinations: Vivid dreamlike experiences that occur while falling asleep or upon wakening. (30%)

Sleep paralysis: Paralysis that occurs most often upon falling asleep or waking up. The person is unable to move for a few minutes. (25%) (Retsas et al, 2000)

Interestingly, regular night time sleep schedule and scheduled naps during the day is required for favourable outcomes (Edgar et al, 2006).

Sleep Apnoea

Sleep apnoea affects over 12 million Americans with it being more prevalent in men than women (Sjosten et al, 2009).  Sleep apnoea not only deprives sleep from the individual but their partners too (Yip, 2001). Sleep apnoea is defined as frequent and loud snoring and breathing cessation for at least 10 second for five or more episodes per hour followed by awakening abruptly with a loud snort as the blood oxygen level drops (Sjorsten et al, 2009).   People with sleep apnoea can experience anywhere between 5 apnoeic episodes per hour to several hundred per night (Sjorsten et al, 2009).

Symptoms of sleep apnoea are:

Excessive daytime sleepiness

Morning headaches

Sore throat

Intellectual deterioration

Personality changes

Behavioural disorders

Obesity

(Yip, 2001)

Obesity is the major cause of sleep apnoea often losing weight is all that is need to treat this disorder (Yip, 2001).

 

Part 3 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.

 

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Pesticide exposure has a big impact on kids IQ and mental development

Pesticide exposure has a big impact on kids IQ and mental development

Residential proximity to agricultural pesticide use has been associated with many adverse health conditions including neural tube defects and autism.

In a long term study of 283 mothers and children 7 years old living in an agricultural area in the US researchers found a decrease of 2.2 points in Full-Scale IQ and 2.9 points in Verbal Comprehension for each increase in toxicity-weighted use of organophosphate pesticides. In separate analysis, they observed similar decrements in Full-Scale IQ with each standard deviation increase of use for two organophosphate pesticides (acephate and oxydemeton-methyl) and three neurotoxic pesticide groups (pyrethroids, neonicotinoids, and manganese fungicides).

As a part of this ongoing research earlier studies from the same research group identified higher levels of organophosphate urinary metabolites or dialkylphosphate (DAP) levels were ∼40% higher than those in a representative sample of U.S. women of childbearing age and had observed a relationship between prenatal maternal DAP concentrations and children’s performance at 2 y measures of attention at 5 y and Intelligence at 7 years. Several studies in other populations have similarly reported adverse associations of prenatal exposure to OP pesticides and child neurodevelopment

This is part of a long list of studies now showing that exposure to these neurotoxic pesticides are linked with poorer neurodevelopment in children even at moderately low exposures. All pesticides are bioactive agents designed to kill.

 

 

https://doi.org/10.1289/EHP504

Robert B. Gunier, et al 2017. Prenatal Residential Proximity to Agricultural Pesticide Use and IQ in 7-Year-Old Children. Environ Health Perspect; DOI:10.1289/EHP504
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