This article originally appeared in the Winter 2003 edition of Celiac.coms Scott-Free Newsletter.
Evolution is an interactive process. Those of us who learn quickly and well are more likely to survive, thrive, and reproduce. Learning capacities then, are factors in the survival of our genes. Research is now revealing that cereal grains, along with other allergenic and highly glycemic foods, pose a serious threat to our sustained ability to learn. These foods have been shown to interfere at almost any stage of the learning process, impeding our attempts to focus our attention, observe, ponder, remember, understand, and apply that understanding. Grains can alter learning capacities in four specific ways: as sequelae of untreated celiac disease; through an immune sensitivity to gluten; through dietary displacement of other nutrients and; through the impact of grain on blood sugar/insulin levels.
There are many reports of learning problems in association with untreated celiac disease. A majority of children with celiac disease display the signs and symptoms of attention deficit disorder (ADD/ADHD)1, 2 a range of learning difficulties3 and developmental delays4-6. Many of the same problems are found more frequently among those with gluten sensitivity7 a condition signaled by immune reactions against this most common element of the modern diet. Grain consumption can also cause specific nutrient deficiencies that are known to play an important role in learning. Grains can also cause problems with blood sugar/insulin levels resulting in reduced capacities for learning. Further, foods derived from grain are an important element in the current epidemic of hypoglycemia, obesity, and Type 2 diabetes8-10. Our growing understanding of the biological impact of cereal grain consumption must move educators to challenge current dietary trends.
Part of our improved understanding comes from new testing protocols which are revealing that celiac sprue afflicts close to 1% of the general population, making it the most common life-long ailment among humans, with frequencies ranging from 0.5% to more than 5% of some populations11, 12. It is widespread and appears to occur more frequently among populations that have experienced relatively shorter periods of exposure to these grains13. The importance of this newly recognized high frequency of celiac disease becomes obvious when we examine the impact it has on learning and behavior.
Research has identified ADHD in 66-70% of children with untreated celiac disease, which resolves on a gluten-free diet, and returns with a gluten challenge1, 2. Several investigators have connected particular patterns of reduced blood flow to specific parts of the brain in ADHD13-15. Other reports have connected untreated celiac disease with similarly abnormal blood flow patterns in the brain16. One might be able to dismiss such reports if viewed in isolation, but the increased rates of learning disabilities among celiac patients3, and the increased rates of celiac disease among those with learning disabilities leave little to the imagination17. Further, there is one report of gluten-induced aphasia (a condition characterized by the loss of speech ability) that resolved after diagnosis and institution of a gluten-free diet18. Still other investigations suggest a causal link between the partial digests of gluten (opioid peptides) and a variety of problems with learning, attention, and development.
Gluten sensitivity, afflicting close to 15% of the general population19, 20 is an immune reaction to one or more proteins in found in grains. When a persons immune system has developed antibodies against any of these proteins, undigested and partly digested food particles have been allowed entry into the bloodstream21. The leakage of food proteins through the intestinal wall signals a failure of the protective, mucosal lining of the gastrointestinal tract, as is consistently found in untreated celiac disease. Many of the same health and learning problems that are found in celiac disease are significantly overrepresented among those with gluten sensitivity for the very good reason that many of the same proteins are being leaked into the blood of those with gluten sensitivity.
Our cultural obeisance to grains is at odds with the remains of ancient humans. Archaeologists have long recognized that grains are a starvation food—one for which we are not well suited. Grains result in consistent signs of disease and malnourishment in every locale and epoch associated with human adoption of grain cultivation.
Grains are a poverty food. As we increase our grain consumption, we cause deficiencies in other nutrients by overwhelming the absorptive and transport mechanisms at work in our intestines. For instance, diets dominated by grains have been shown to induce iron deficiency22—a condition that is widely recognized as causing learning disabilities23-29. This should not be surprising since iron is the carrier used to distribute oxygen throughout our bodies, including various regions of our brains. There is little room to dispute the hazards to learning posed by reductions in oxygen supply to the brain. Iron deficiency reduces available oxygen in the brain, revealing yet another dimension of gluten grains as mediators of learning difficulties.
There is more. The impact of grain consumption on our blood sugar levels is yet another facet of its contribution to learning problems. We evolved as hunter-gatherers, eating meats, and complex carbohydrates in the form of fruits, vegetables, and seeds. Refined sugars were a rare treat wrested from bees with some difficulty. At best, it was a rare treat for our pre-historic ancestors.
Today, with unprecedented agricultural/industrial production of refined sugars along with cultivation and milling of grain flours, these products have become very cheap and available, particularly over the last fifty years. During that time, we have added enormous quantities of grain-derived starches to the overwhelming quantities of sugar we consume. The result of this escalating dietary trend may be observed in the current epidemic rates of Type 2 diabetes, hypoglycemia, obesity, and cardiovascular disease. In the classroom, we see these trends manifest in students mood swings, behavioral disorders (fluctuating between extreme lethargy and hyperactivity), chronic depression, forgetfulness, and muddled thinking—all of which reflects the inordinate, counter-evolutionary burden placed on many homeostatic systems of the body, particularly those related to blood sugar regulation.
The pancreas has many functions. One important activity of the pancreas is to stabilize blood sugar levels. When blood sugar is not well regulated, learning is impaired30. The pancreas secretes carefully monitored quantities of glucagon and insulin. The pancreas responds to the presence of proteins, sugar, and starch in the digestive tract by producing insulin. It produces glucagon in response to fats. The balanced presence of both of these hormones in the bloodstream is critical to learning because they regulate the transport of nutrients into cells. Too little or too much insulin can cause blood sugar levels go out of control inducing a wide range of symptoms.
Today, when the insulin/glucagon balance goes awry, it is frequently due to insulin overproduction due to a diet dominated by sugars and starches. This overproduction is caused by chronic consumption of highly glycemic foods. The resulting elevated levels of insulin cause rapid movement of nutrients into cells, either for storage as fat, or to be burned as energy, causing increased activity levels, "hot spells", sweating, increased heart rate, etc. This energized stage requires a constant supply of sugars and starches to be maintained. Otherwise, it is soon followed by bouts of lethargy, light-headedness, tremors, and weakness, which are all signs of hypoglycemia or very low blood sugar levels.
Despite having stored much of the blood sugars as fats, there is insufficient glucagon to facilitate its use for energy. As this condition progresses, and as blood sugar levels plummet, periods of irrational anger and/or confusion often result. These moods often result from adrenaline secreted to avoid a loss of consciousness due to low blood sugar levels. The next step in the progression, in the absence of appropriate nutritional intervention, is lapsing into a coma.
In the short term, the answer to these fluctuations is more frequent consumption of sugars/starches. However, the long term result of such an approach is either a state of insulin resistance, where more and more insulin is required to do the same task, or a state of pancreatic insufficiency, where the pancreas is simply unable to keep pace with the demand for insulin. In either case, once this stage is reached, the individual may be diagnosed with type 2 diabetes. This disease has so increased among North Americans, particularly among children, that an autoimmune form of diabetes, previously called juvenile onset, had to be renamed to "Type 1 diabetes".
By now, it will not surprise the reader to learn that Type 1 diabetes has also been shown to be significantly associated with gluten. Research reveals that there is considerable overlap between celiac disease and Type 1 diabetes. About 8% of celiacs also have Type 1 diabetes31-33, and 5-11% of Type 1 diabetics have celiac disease34-38. Further, Scott Frazer et al. have repeatedly shown, in animal studies, a causal, dose-dependent relationship between type 1 diabetes and gluten39-42.
The growing reaction against gluten and other allergenic foods should not be confused with the several dietary fads of the 20th Century. The vegetarian perspective ignores the vitamin deficiencies that result from a strict vegetarian diet. The low-fat craze is another fad that has mesmerized the industrialized world for the last 30-40 years. Fortunately, this perspective has recently come under scrutiny. Despite having served as the driving force behind most physicians dietary recommendations during the last several decades, the low fat dictum is overwhelmingly being discredited by research reported in peer reviewed publications.
Recognition and avoidance of allergenic and highly glycemic foods is a whole new trend that is based on scientific research and evidence. It reflects an improved understanding of the function of the gastrointestinal tract, the endocrine system, particularly the pancreas, and the immune system. Past dietary fads are consistently deficient in important nutrients that are necessary to our good health and survival. Further, they frequently contain substances that are harmful to us, such as the phytates that are abundantly present in whole grain foods, and interfere with absorption of many minerals.
It is increasingly clear that grains, especially those that contain gluten, are contraindicated for human learning. The evidence is overwhelming. The mandate of eating to learn is learning to eat as our ancestors did.
Ron Hoggan is an author, teacher and diagnosed celiac who lives in Canada. His book "Dangerous Grains" can be ordered here.