For an increasing number of children returning to school this fall, the experience of learning is a guilt-ridden, fear-inducing and often pointless exercise. The numbers of children considered to have learning difficulties of one sort or another have skyrocketed over the past 25 years, so much so that it's a rare school these days that hasn't set up a special-needs unit to deal with the growing numbers of children who cannot follow the ordinary curriculum. Although many reports are unofficial, parallel trends have been reported all over the world.
The broad-brush label 'learning difficulties' is used to describe any one of a number of symptoms: difficulty in reading and writing, a short attention span, poor concentration and an inability to retain information. The more severe learning disorders go by the labels 'dyslexia' (inability to process words), 'dyspraxia' (physical clumsiness), 'dyscalculia' (inability to process numbers), attention-deficit disorder (with or without hyperactivity) and even autism. However, more and more children with no obvious learning problems are struggling with the accelerated, fast-paced curriculum of today's schools.
The diagnosis of learning difficulties is complex as the condition often results from disorders that may have several root causes and a wide range of other symptoms. A child may find it difficult to learn or retain information because of behavioural problems that may be due to as yet unidentified psychological or physical factors. The problems may also be the result of a physical handicap, such as poor hearing or eyesight, that has not yet been recognised in someone so young.
Nevertheless, an increasing body of evidence now shows that the root cause of so-called learning difficulties for the vast majority of children may be biochemical - something fundamental that is either lacking or causing a chemical insult to the body.
The simple and outrageous fact is that children labelled as 'learning disabled' may simply have extra needs for certain nutrients, or suffer from one or another food or chemical intolerances, causing a biochemical reaction in the brain. An inappropriate and medical-sounding diagnosis may label a child as somehow mentally defective for life.
Indeed, in many instances, it may be that modern medicine lies at the root of the problem - drugs given too early that have injured the bodies of these children, making them more susceptible to further chemical insults.
In the UK, some 2 per cent of children in the UK between 6 and 16 years of age are diagnosed with ADHD (69,000 severely so), 10 per cent are considered dyslexic (375,000 severely so) and 0.6 per cent are said to have an autistic-spectrum disorder. In the US and Australia, up to 10 per cent of children in both countries are labelled as ADHD. Some researchers estimate that as many as 20 per cent of children in both the UK and US are now considered hard-core problem learners.
In the case of autism, The Lancet presented evidence of a massive 1700 per cent increase in the incidence of autism between 1979 and 1992 (Lancet, 1999; 353: 2026-9).
The medical approach to disorders that give rise to learning difficulties are mostly treated as a social problem or a 'sick brain'. Doctors tend to treat behavioural aspects with drugs to suppress symptoms and ignore the learning problems, often to the detriment of the child concerned.
Since the 1960s, the drug methylphenidate (MPH), more commonly known as Ritalin, has been prescribed to thousands of children. Currently, up to 20 per cent of all American school-age children, and 10 per cent of Australian children, are taking long-term prescriptions of this drug.
In the UK, this psychostimulant, which mimics the properties of cocaine, is a class B drug (class A when in solution). By 1999, the number of prescriptions being issued for Ritalin reached 131,000 per year, up from 6000 a year in 1994 - representing more than 2 per cent of all UK children. This figure is likely to be a low estimate as it does not include the prescriptions given out in private practices, young-offender centres or care homes.
There is a lack of research to support the use of Ritalin to control ADHD, and a load of evidence pointing to a battery of worrying side-effects, including gastrointestinal and liver effects, drug dependency, agitation, abnormal thoughts and psychotic depression (Ethical Hum Sci Serv, 1999; 1: 13-33).
Despite this, US drug companies have successfully persuaded health authorities and psychiatrists of Ritalin's supposed benefits. In 1998, at a conference on ADHD, the US National Institutes of Health stated that there were 'no data to indicate that ADHD is due to a brain malfunction', despite the assertion by the Ritalin lobby that it works by correcting a 'brain disorder'.
With autism, the drug of choice is secretin, a polypeptide hormone involved in gastric function. Using this hormone for autism is based on sturdier principles than for MPH as it acknowledges the link between a malfunctioning digestive system and the condition. Secretin facilitates enzymatic digestion in the small intestine. It may, however, disrupt digestion in the stomach.
A common cause
Although ADHD, learning disabilities and autism are supposedly separate conditions, their similar symptoms suggest a possible common cause. Roughly half of all symptoms of ADHD and dyslexia overlap and, along with autism, they share a number of common physical problems - a tendency to allergies/sensitivities, skin problems, sleeping disorders and poor motor coordination.
Some pioneers in the field of learning disabilities have postulated that all have a common base: certain fundamental nutritional deficiencies because of higher-than-normal biochemical needs.
Sally Bunday, herself the mother of a hyperactive child, and her mother Irene Colquhoun were the first to hypothesise an association between nutrition and ADHD (Med Hypoth, 1981; 7: 673-9). They found a link between ADHD and asthma, eczema and other allergy-type conditions. These children also suffered from excessive thirst, and dry skin and hair, consistent with a deficiency of essential fatty acids (EFAs).
Their idea has since been verified by numerous studies concluding that an EFA deficiency is also a major factor in other, interrelated disorders. UK researchers have found further evidence that fatty-acid and membrane-phospholipid abnormalities are both involved in a range of neurodevelopmental and psychiatric disorders, including ADHD, dyslexia, dyspraxia and autism - illnesses that are now said to fall within a 'phospholipid spectrum' of disorders.
What this research suggests is that those who have so-called learning problems, as well as the more traditional mental problems, have a fundamental difficulty in processing fats and, therefore, need more of it than usual to function normally. This would explain the overlapping symptoms, the tendency to run in families and the symptom similarities with the more traditional psychiatric disorders (Prostagl Leukotr Essent Fatty Acids, 2000; 63: 1-9).
EFAs play an essential role in brain structure and function. Around 20 per cent of the dry weight of the brain and 30 per cent of the retina are made of highly unsaturated fatty acids (HUFAs). As EFAs cannot be synthesised by the body, they must be supplied by the diet in the form of linoleic acid and alpha-linolenic acid, precursors from which other fatty acids, such as docosahexaenoic acid (DHA), and compounds are synthesised that are vital to proper brain functioning, nerve synapses and photoreceptors. Deficiencies of these omega-3 fats have been linked to visual and mental problems (J Pediatr, 1994; 125: S39-47; Proc Natl Acad Sci USA, 1986; 83: 4021-5).
Role of wheat and dairy
Besides EFAs, some foods are virtual brain poisons to certain individuals. The Autism Research Unit at the University of Sunderland has conducted studies involving more than 1200 children, over an 11-year period, and found that autism is a metabolic disorder rather than a mental one.
The ARU researchers concluded that autism is the result of peptides outside the brain and nervous system causing opioid activity or the breakdown of the body's own opioid peptides. These naturally occurring peptides include enkephalins and endorphins, and play a key role in regulating brain and neurological function. Disruption of their activities may, in turn, affect perception, cognition, emotions, mood and behaviour.
In autism, the gut problems are caused by an initial insult - from the MMR vaccine, illnesses such as encephalitis and meningitis, or even an overload of pesticides. There is also evidence that autism can be caused by broad-spectrum antibiotics, possibly as a result of their effect on the immune system. Genetic factors may also predispose an individual to gut abnormalities.
The controversial research carried out by gastroenterologist Dr Andrew Wakefield at the Royal Free Hospital in London into the MMR vaccine revealed bowel abnormalities in a large number of 18-month-old children who developed the gut problems and autism shortly after receiving the triple vaccination. Urine tests also showed that these children had significant vitamin B12 deficiency, a vitamin necessary for brain and nervous system development (Lancet, 1998; 351: 637-41).
The theory proposed by Dr Wakefield and Paul Shattock, of the ARU, is that the MMR vaccine overloads the immune system, enabling a weak measles infection to become established in the gut. The bowel is then unable to produce sufficient enzymes to digest food properly and the gut becomes permeable or 'leaky', allowing short-chain amino acids from partially digested milk and wheat to pass into the bloodstream. Some of these molecules enter the brain, where they can interfere with neural functioning. This process can be exacerbated in a child who is low in EFAs, which itself can reduce immune function and cause digestive disorders.
When wheat and casein (the main protein in milk) are broken down in a baby's stomach, they produce casamorphins and glutamorphins.
'Casamorphins effectively drug the baby,' says Mr Shattock. 'That effect of milk and wheat on a baby's brain should stop when the child grows, but if it doesn't, we believe that conditions like autism and dyslexia occur.'
Removing dietary gluten and casein may offer a simple solution. In autistic children, removing gluten from the diet resulted in significant improvements in the majority of them, particularly in concentration, sleep patterns and language development (Autism, 1999; 3: 45-69). Many children suffered withdrawal effects, with many symptoms initially getting worse probably because of the loss of opioids (produced by gluten-containing foods), which had led to dependency effects similar to those seen with narcotics.
However, children with a damaged gut may not be the only ones to benefit from a milk- and gluten-free diet (see box above).
A toxic onslaught
Another area to consider is the modern child's increasingly toxic environment, combined with a diet of ever-decreasing nutritional value. Today's children are assaulted with heavy-metal pollution and additives in food. Exposure to lead, even at low levels, is associated with aggression and learning disabilities, as is exposure to mercury. Children nowadays come into contact with heavy metals through tapwater, air pollution, tobacco smoke, fish and shellfish, pesticides, children's vaccines (mercury-based thimerosol is a common preservative), processed foods and toiletries. Just tiny amounts stored in the body can have an adverse effect on health.
A wealth of evidence shows that toxic metals can compromise the immune system, and damage the nervous system and brain. Raised levels are associated with decreased concentration and organisational skills, problems with speech and language comprehension, and lowered intelligence. Metals are implicated in autism, dyslexia and ADHD.
Contributing to the 'dumbing down' of this generation is the poor state of our food. Nearly every study in the last century found that agricultural land, vastly overused and oversprayed with pesticides, is now depleted of minerals. The 1992 Earth Summit in Rio de Janeiro reported that US farmland was 85 per cent depleted of minerals while the overall worldwide depletion was 75 per cent. Manganese, zinc and iron were particularly low (FAO Soils Bull No 63, Rome, 1990).
It's not just minerals that are lacking. Modern-day crops of wheat are around 9 per cent protein compared with 90 per cent in 1900. US Department of Agriculture handbooks reveal that the vitamin content of fruit and vegetables has also declined across the board, with the beta-carotene in broccoli and the vitamin C in cauliflower both down 50 per cent since 1963.
Vitamins and minerals are important in brain chemistry, and a deficiency in only one can result in a diminished mental capacity, mental and emotional disturbances, behavioural disorders and autism (Int J Bio Soc Res, 1981; 1: 21-41). It is not unreasonable, then, to consider at least a partial link between the decline in soil nutrients and the rise in learning difficulties.
Poor nutrition sets up a vicious cycle - it leads to the increased uptake of toxic metals which, in their turn, further interfere with the absorption of essential nutrients like magnesium, zinc, lithium, iron and the B vitamins. Brain cells, for example, absorb more toxic metals when the diet is low in calcium, iron, zinc, vitamin D and other essential nutrients.
What foods children do eat these days is often highly processed and filled with additives, many of which have proven links with conditions such as ADHD. One such additive is the artificial sweetener aspartame, which contains phenylalanine, a compound known to have a toxic effect on neurological functioning, with symptoms consistent with ADHD, if present at high levels in children. It can also affect children prenatally if ingested by the mother (Neuropsychology, 2003; 17: 458-68).
The best headstart for every child today, whether or not he is considered learning disabled, is a wholefood, unprocessed diet, rich in essential fatty acids, low in or free of gluten and dairy.
Michelle Clare and Lynne McTaggart