Abnormalities in Children with Behavioural and Learning Difficulties
Dr. Robyn Cosford MBBS (Hons), FACNEM
Paper given at The Mind of a Child Conference, August 1999
Children are a blessing from the Lord; the fruit of the womb is a reward... How blessed is the man whose quiver is full of them. David, Ps 127:3.5
Despite the great technological and medical advances of the scientific age, childhood illnesses are increasing. Asthma has doubled over the past 20 years to a rate of up to 35% of Australian children, Australia having the third highest prevalence rate in the world. Allergies are also increasing, with a recent study revealing that 54% of the children in the UK suffering atopic symptoms at some time.
Otitis media affects 80% of children by the age of 3 and is regarded as normal, and 15% of children suffer glue ear during winter at the age of 6 years. The incidence of childhood brain tumours has increased during the last 20 years by 35%.
Mental illness has also increased, with the age of onset of depression becoming younger, even as young as children aged 5 years, and with some 7-10% of the young with anorexia or depression and thousands of primary school children on antidepressant medication. In the UK, 20% of the children have mental health problems (enuresis being included in this survey).
As these children grow, the long term outlook does not improve. The long term outlook of adolescents admitted to psychiatric wards is poor, with a 10 year morality rate at 40%, similar to that for childhood cancer, and 95% of males who abused drugs and had had disciplinary problems went on to have a criminal record, disability or to die. The youth suicide rate tripled between 1960 and 1990, with Australia having the highest rate in the world.
Considering behavioural, developmental and learning difficulties, we see a similar pattern, with specific learning disorders in up to 20% of children. ADD is increasing dramatically, with a diagnosis rate in the USA of 900,000 in 1990 rising to over 5,000,000 in 1997. Although some of this increase can be attributed to an increased awareness rate, it appears that the real incidence is increasing.
Some 91% of these children are medicated, with 3.5 million people using Ritalin and 1.4 million people using other medications, mostly dexamphetamine, in the USA in 1997. There is an increasing trend to early diagnosis and multiple psychotropic medication use, as revealed in a recent US study of 2000 children, where 200 different drug combinations were used. In Australia dexamphetamine use has increased from 16,405 in 1992-1993 to 162,497 in 1997-1998 (PBS figures).
Autism is also apparently increasing, from an incidence rate of 1 in 10,000 20 years ago to 0.9% in Japan at present, with US figures presented at a recent Washington House of Representatives Committee revealing a nationwide incidence of 5,400 in 1991 increasing annually to 34,100 in 1996 with no signs of plateauing. Figures from the UK present a similar pattern.
The total health of our children is deteriorating. For children under the age of 5, the most recent ABS study found that the commonest illnesses are infectious or parasitic, otitis media, URTIs or asthma, with 58% of all children under the age of 5 having been ill in the previous 2 weeks, and 30% of these children having long term illness. when considering children aged 5 to 14 years, it was found that only 30% had been well in the previous 2 weeks,with 49.8% with long term illness.
There are many factors contributing to this deterioration in our childrens health.
A major area of change affecting our children has been that of societal change. We have changed from being tribal, to village communities, to extended families, to nuclear families, to, increasingly, single parent families. We have changed from being hunter gatherers to nomadic herders, to farmers, to city workers: 1999 marked the first time in the history of man that there were more people living in cities than on the land. Family structure has changed from that of large families, with often 10 or more siblings, to 2 child families (current average 1.8 children).
We have changed our family functioning, from mothers with their young children, to increasingly, mothers out of home, at work, and fathers from being part of the tribe with young boys growing up learning their fathers skills, to fathers working long days away from the family, with no passing on of work skills and often little to do with the raising of their boys.
Child and infant care patterns have also changed. We have changed from carrying our infants continually close to their mothers, comforted or carried to sleep, and sleeping whole families to a room; to having our babies continually placed in strollers, or down to play, taught how to self-settle; to sleep (controlled crying) and put to sleep in separate rooms.
We no longer routinely breastfeed for the first three or so years of life, with continuously suckling as desired, but instead breastfeed usually only for the first few months, at set times,with the use of breastfeeding for comfort being actively discouraged. Now less than 10% of babies are breastfed for longer than 12 months. Children have gone from being cared for by the tribe, to being cared for by the family, to being cared for by only the mother or increasingly, in out-of-home day care or institutionalised long day care centres.
In addition to these societal changes, there are many environmental influences exerted on our children. There are many influences during pregnancy which have been documented to exert an effect on the child. Smoking is one such factor. 21% of Australian women smoke during pregnancy, which increases the risk of spontaneous abortion, placental abruption, premature rupture of the membranes, low birth weight, perinatal death, SIDS, and abnormal lung development.
The risk is worse for heavy smokers,with those with high cotinine levels being demonstrated to have a 33% chance of poor pregnancy outcome as measured by premature delivery before 37 weeks gestation or intra-uterine growth retardation, with birth weights less than the 5th centile. Maternal smoking has also been demonstrated to damage the foetal brainstem.
Other social drugs, caffeine and alcohol have also been demonstrated to cause foetal harm.Caffeine in excess of 400 mg per day, equivalent to 4 cups, has been shown to increase the risk of low birth weight, spontaneous abortion and neonatal apnoea.
Given that the mean daily intake of caffeine in adults over the age of 19 in 1995 was over 400 gm, this may be significant. Alcohol in excess of 10 drinks per week has long been associated with the foetal alcohol syndrome in which there are characteristic foetal abnormalities, lowered IQ, behavioural difficulties such as ADHD and conduct disorder, psychiatric illness and gut nerotoxicity with resultant abnormal gut peristalsis.
However, recent research indicates that as little as 4 glasses per week will dull the foetal response to sound stimulus indicating brainstem damage and over 55% of the adult population consume greater than 1 alcoholic drink per week, with females averaging 33ml per day.
More recent in our society is the widespread use of chemicals. Maternal to foetal transport of various neuro-toxicants can occur readily and studies have shown that workplace exposure to solvents for greater than 20 hours per week during the first trimester results in a 12% chance of foetal malformation, predominantly deafness, talipes, and congenital cardiac defects. This compares to a rate of 1 to 3% in the normal population.
Electromagnetic radiation is another recent addition to our environment, and high exposure to electromagnetic fields has been shown to result in increased pregnancy loss. Computer use has been linked with miscarriages, prematurity and still births and birth deformities.
We live in an increasingly stressful society and maternal stress has been demonstrated to adversely affect the pregnancy: high psychological stress levels have been associated with a significant impairment of uterine blood flow in 25% of stressed mothers, with abnormal flow being predicative of intra-uterine growth retardation and pre-eclampsia, and stress results in an increased incidence of low birth weight babies.
Work-related stress has also been shown to be detrimental, with working in waitressing, cooking, or as a nursing assistant being associated with a 3 times risk of pre-eclampsia and twice the risk of gestational hypertension.
As a consequence of these and other factors, prematurity, low birth weight and very low birth weight is increasing in incidence. These are associated with severe cognitive impairment in 25%, moderate to mild psychological problems, increased incidence of ADHD and schooling difficulties requiring special education or assistance. Even before birth, babies are subject to these factors which may place them at risk of future developmental, behavioural or learning disorders.
During infancy there are added factors influencing the health of our children. It would appear that our infant care practices may affect our childrens neurological development. It is regarded as a normal for an infant to cry for 3 hours per day at the age of 6 weeks in our society. This is in stark contrast to tribal societies such as in Africa and the Pacific Islands where babies are carried all day and it is well documented that in a village of 100 babies, there may not be a single baby who cries. Regrettably this system is not convenient to Western mothers.
Controlled crying is the favoured form of management of infantile sleep difficulties in our society, and we are told to resist comforting a crying baby so it can teach itself to go to sleep. Some doctors disagree with this approach, explaining that research suggests that adverse experiences may make a difference to brain development.
Breastfeeding, as already mentioned, has reduced dramatically since the turn of the century, with only 10% of children being fed for more than 12 months. 86% of children are breastfed at some time, but this drops to 65% at 2 months and 50% at six months. Breastfeeding for greater than 8 months has been associated with increased IQ, increased performance on standardised tests, higher teacher ratings and better high school achievement, after adjusting for other variables.
Conversely, not being breastfed has been correlated with the lowest scores on WISC, the lowest teacher rating of achievement in reading and maths, the lowest level of high school attainment and the highest level of leaving school without qualifications (after adjusting for other variables) and bottle feeding has been associated with double the risk of ADHD.
In addition to influences on mental function, breastfeeding has been shown to protect against diarrhoea and respiratory illness: increasing breastfeeding rates by 40% would result in a reduction of respiratory deaths by 50% and diarrhoeal deaths by 66% in children under 18 months old worldwide. Breastfeeding for greater than 3 to 4 months also protects against otitis media, protection lasting for up to 3 years and invasive Haemophilus influenzae,with protection significantly increasing for each week of breastfeeding greater than 13 weeks and duration of up to 10 years. This loss of protection is a significant factor in the high incidence of infection seen in our children.
The increasing rates of allergy now seen in our children may also be related to the reduction in protection afforded by breastfeeding. Breastfeeding for greater than 1 month has been shown to reduce food allergy at 1 and 3 years old, asthma and hayfever to the age of 17 years. The risk of atopy and asthma is closely linked to the age at which non-breast milk is first introduced.
Another influence on our children's health in recent years is that of vaccinations which were introduced some 45 years ago. Our children now receive up to 30 vaccinations before commencing school, many in conjugate vaccines, for up to 1 to 10 different infections. Vaccinations are clearly a noxious stimulus, associated with pain and subjective feelings of unwellness.
In addition to the attenuated virus or inactivated toxoid intentionally injected, there are other vaccine components to consider which may be included: foreign proteins from the growth medium (pertussis vaccine is grown in casein hydrolysate mixture); viral particles form the cell cultures; adjuvants, particularly aluminium ($9,445,057 worth of adjuvants were sold in 1997), and preservatives, including formalin and thiomersol, a mercury derivative.
Interestingly, cross species viruses and bacteria are being increasingly transferred from animal to man. The true short term side effect rate of vaccines is now known as drug side effects are notoriously underreported, although a significant minority are documented to suffer long term sequelae. It is known that premature babies when vaccinated have increased apnoeic spells and bradycardic episodes which are managed by routinely using apnoea monitors.
A recent study from Switzerland found that children who have had fewer vaccines, fewer antibiotics and have diets containing live lactobacilli have a reduced incidence of atopy. There are currently increasing reports in the world literature of associations between vaccination, particularly the MMR vaccine, and autism.
Antibiotics are another phenomenon unique to modern society, with usage worldwide increasin. In the year to December 1998, $250,204,507 was spent on antibiotics, up 1.66% on the previous year,of which Amoxil,which is commonly used in children, accounted for $22,732,397. Interestingly, males under 15 years were the highest antibiotic usage group, with 6% having used antibiotics in a 2 week period, of which 27% were for otitis media.
Numerous trials have shown that antibiotic use for acute otitis media, sore throats and bronchitis provide little clinical benefit, and in the UK, general practitioners have been officially requested to cease antibiotic use in humans and animals is of questionable therapeutic benefit. Antibiotics have been correlated with increased risk of asthma, if used in children under age 12 months, and are well documented to disrupt gastrointestinal flora.
In addition to those influences already mentioned, there are other issues related to childhood which influence our children's health. Diet has changed dramatically from the original hunter gatherer diet, with all complex carbohydrates, no refined sugars, natural sugars from sources such as dates, figs,fruits and occasional wild honey,higher omega 3 essential fatty acids (often quoted as 1:4 omega 6), soured dairy products and chewy foods.
In contrast, modern western society diets are high in refined carbohydrates, with cane sugar in manufactured foods totaling 31.7 kg per capita in 1997, added refined sugar 11.1kg and total sugar intake 42.8kg per capita, with 29% of domestic sugar sales going into non-alcoholic beverages. This sugar intake compares with a bread intake of 51 kg per year. The modern diet is also characterised by an increased omega 6 essential fatty acid intake, increased trans fatty acids in processed foods, softer foods, a high dairy intake with mean intake of over 250gm milk per day, a low fruit intake particularly in young males of whom only 37% ate any fruit, and a low vegetable intake other than potato. Fruit, vegetable,fish and fresh food intake halved from 1961 to 1985.
In addition to these dietary changes has been the inclusion of genetically engineered foods into our diet. Currently, soy, cotton (as cottonseed oil), canola, sugar beet,tomato and animal rennet in cheese are genetically modified. The questions raised are those of introduced foreign genetic matter and the use of genetic engineering against herbicides and pesticides to allow the increased use of chemicals on food, as has occurred with soybeans genetically engineered to be resistant to the herbicide Roundup and the consequential increase in allowed Roundup levels in food.
We have changed in our diet from foods freshly harvested when ripe, home prepared and eaten, to foods green harvested, stored, processed, pre-prepared and eaten away from home.
The widespread use of chemicals in our modern society is another influence on the health of our children. At total of $1,355,695,967 in agricultural chemicals was sold in 1997, including chemicals used in schools: cleaning agents, insecticides, science chemicals and gas, and chemicals for the home: $144,686,160: disinfectants, sanitisers, and household insecticides.
Children are more sensitive to these chemicals than adults and the effects of air pollution are 6 times greater for children. Some of the pesticides used in schools are neurotoxic and may cause vomiting, diarrhoea, convulsions, headaches,skin irritations,hepatic damage, and behavioural and emotional disturbances; and shortened attention span, hyperirritability, aggressiveness, sensory and motor impairment have been identified as an early sign of toxicity or increased reaction to environmental chemicals.
The use of chemicals in food is more difficult to quantify as industry figures are not available for what is included in foods, only that over 400 food additives are allowed. Notably the caffeine in soft drinks in the UK has been found to be as high as 350 mg/1, nearly 3 times the allowed figure of less than 125mg. The use of chemicals for veterinary purposes, most in livestock and therefore in food gives a guide to chemicals in food: $448,913,252 in l997, with $34,937,225 for antibiotics and related substances.
The total of chemicals used for food production, including herbicides and insecticides totalled $1,236,248,833 in 1997. It appears that human exposure to pesticides is far greater than was previously thought. Children are at particularly high risk for neurotoxic effects from regular inadvertant exposure to pesticides in common foods.
Sound pollution is another feature of modern society which has been demonstrated to affect the health of our children. Aside from the issue of noise-induced deafness as a consequence of the volume at which music is played particularly in cars and at concerts, is the issue of measurable increased stress from chronic noise exposure, as measured by increased blood pressure readings. Children attending school near Heathrow had 6 months delay in reading ability, 6 months delay in comprehension, were less attentive and more stressed: these affects were increased 1 year later. Similar results were found for Los Angeles, Munich and Sydney airports.
Other types of electromagnetic radiation have also increased in our modern society. The human body is electrical, with our cells vibrating at characteristic measurable frequencies. The brain for example, vibrates at 1-30 Hz. The structure of our brain,with the central corpus callosum, has been likened to a radio-receiver/transmitter, which if true, could make our brains highly susceptible to abnormal electromagnetic frequencies.
Our previous electromagnetic exposure was predominantly geomagnetic, at 10Hz, and household appliances, many with frequencies around 50 Hz. Microwaves for cooking and communication have become commonplace.
Microwave cooking is well known to heat by molecular vibration, this vibration altering the protein isomerisation from natural L-isomers, to unnatural D-isomers. The effect of this on our metabolism is not known at this point. The effects of microwave transmission towers is controversial. It is known that children absorb 3 times the radiation of adults, and that electromagnetic fields (EMF) can reduce the quality and quantity of sleep, and reduce REM sleep with associated reductions in memory and learning.
The final major environmental component of modern society which has demonstrated effects on the health of our chilren, is that of television, video games and computer usage.Currently, toddlers are watching an average of 2 1/2 hours per day of television, with more in older children. There are several issues of concern with television watching. The first, as already mentioned, is the issue of electromagnetic radiation exposure.
An electric field emanates from the front of the television and from computers, for a distance of approximately 1 metre, and a magnetic field extends from the front and back of a computer, and the back of the television, also for a distance of 1 metre.There are chemical exposure concerns also, with fumes from brominated flame retardants (BFRs) being emitted from hot televisions and computers. Foetal mice exposed to low levels of these BFRs have been shown to develop permanent brain damage including reduced learning capacity and hyperactive behaviour, and the levels of brominated diphenylether in the breast milk of Swedish women has increased 50 times in the past 25 years.
In addition to the electromagnetic and chemical concerns with television and computer usage, are concerns about format and content. Information is presented in short, sharp bursts, training short attentions pans, particularly in toddlers shows, cartoons and music video clips. The use of video games has been correlated with increased nonverbal IQ and spatial skills, but at the expense of social intelligence and responsibility.
Television also has profound effects on lifestyle factors for children. Increased television watching is associated with reduced fitness, and television rationing has been found to be an effective treatment for overweight in children and teenagers.The link with television and obesity amongst adolescents is sufficiently strong as to suggest causation., Television is actively presenting wrong messages about alcohol and smoking, good characters using tobacco and alcohol as frequently as bad characters in childrens animated films and advertising, with 2/3 of childrens film having a least one character using tobacco and alcohol.
Television, together with magazines, is the major source of nutritional information for Australian teenagers: poor nutritional messages are also a feature of childrens television. Advertisements during childrens shows are usually for foods high in fat, salt and sugar, with 22% being for chocolate and 25% for fast food restaurants and children who are watching a lot of television consume fruit and vegetables less often and high fat foods more often.
Notably, increased suicide rates have been shown to occur following suicides on television shows: there was an increased incidence of paracetomol overdoses for 3 weeks following a major BBC drama only in those who watched the episode. In younger children, watching television before bed was the strongest predictor of resistance going to bed, anxiety about sleep, delayed sleep onset and shortened sleep duration. Watching violent shows has been associated with at least one type of sleep disturbance, with similar problems occurring when greater than 2 hours of television is watched per day.
The issue of violence in television shows is of major concern. Violence is portrayed in 66% of childrens shows, with the average American teenager being exposed to 14,000 sex-related references per year and children watching greater than 200,00 acts of violence on television, including 16,000 murders before the age of 18 years.
For video games, 1/3 of the top video games for 1999 had violent content. Evidence indicates that on screen violence can teach children aggression, desensitise them to violence, and make them afraid. Violent games have been used by the military to increase soldier fire rates in battle, from 20% in WWII to 95% by the Vietnam War, and the children in the Littleton Colorado school massacre in USA were known to spend hours playing violent games.
It is apparent that there are many factors influencing the minds and health of our children.
Finally, brethren, whatever is true, whatever is honourable, whatever is just, whatever is pure, whatever is lovely, whatever is gracious, if there is any excellence, if there is anything worthy of praise, think about these things. Paul, Phil 4:8
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