Food Allergies Change Brain Electrical Activity and Results in ADHD Symptoms

The connection between food allergies and ADHD has been a hot topic of debate in recent years. A number of studies have shown that adverse reactions to specific foods or combinations of foods and food additives can exacerbate several of the trademark characteristics of ADHD, including hyperactive behavior and reduced attentional ability. The aim of this post is share how adverse reactions to foods can actually impact brain wave frequencies in specific regions of the brain, which in turn leads to an increase in ADHD symptoms.

Before we go any further in this discussion, we must briefly review how ADHD is clinically diagnosed. Simply exhibiting hyperactive, inattentive or impulsive behavior does not necessarily qualify one as ADHD. One of the most common diagnostic tools for identifying the disorder in children is the Conner's Rating Scale (Please note that this link is to a commercial website which provides different versions of the test. It contains some good information about the nature of the different forms of the rating system, which is why I provided the link. This blogger declares no financial ties or commercial interests to this organization). There are multiple versions of this diagnostic test, but they all focus on scoring an individual on a numerical scale in a number of different areas such as inattention, hyperactivity, conduct issues, etc. Using this test as a diagnostic criteria, specific numerical cutoff scores (higher numerical scores indicate more ADHD symptoms) are used to help determine whether a child qualifies as being ADHD. In addition, there must be a persistence of these symptoms for at least 6 months in order for an accurate clinical diagnosis to occur. Of course, some subjectivity is involved in this process, since the rating scale is typically done by teachers, parents or other caregivers who may have internal biases as to whether they think the child has ADHD, but the overall accuracy and success of the test has been relatively well-documented. Keep in mind that there are other factors which trained professionals also use in making a diagnosis, but the Conner's rating scale scores often play a critical role in the process.

Returning to our topic of discussion, there has been relatively little research done on the actual mechanisms of the effect of food allergies on ADHD symptoms. However, there was a 1997 study done by Uhlig and coworkers which is of potential interest. This group studied the effects of food allergies on changes in brainwave frequencies throughout sixteen different regions of the brain. Note that we have discussed the topic of brainwave pattern differences in individuals with ADHD in an earlier post titled Genes and ADHD Brainwave Patterns. A summary of the components key findings of the study are listed below:

• Twelve children with known food allergies (not severe enough to pose a danger) had their brain wave patterns measured via EEG (electroencephalography) in sixteen different brain regions after both a 5 day period of consuming the allergy-provoking foods and a two-week period of avoiding these foods, and the results were compared between the two measurements.

• 10 of the 12 children had previously been tested and shown to have Conner's rating scale scores that were below the threshold for ADHD when the provoking foods were avoided and above the threshold when the foods were included in the diet. In other words, with all other things being equal, consumption allergy-provoking foods caused enough of a change in symptoms to push all twelve of the individuals over the threshold and into ADHD territory. A quick summary of the huge difference in most of the scores can be seen in the table below (note that the "cutoff" score for ADHD is 15 or above for the scale being used, these numbers are highlighted in black):

Note that significant changes in the Conner's rating scale were seen in all 12 children, and 10 of the 12 children's scores crossed the ADHD threshold score of 15 with regular consumption of provoking foods, including one who made a huge jump from 6 all the way up to 25. This shows how intolerance to specific foods can have a huge impact on Conner's rating scale scores and can easily push a child over the limit and can lead to an ADHD diagnosis. If these foods (with which the individual is often unaware of being provoking and a cause of an increase in ADHD symptoms) are consumed on a consistent basis, it is easy to see how 6 continuous months of symptoms can occur and lead to an ADHD diagnosis. While this is based on a small sample, and was not the main purpose of the study, these findings really do raise questions as to how many cases of ADHD arise simply from food-related intolerances, and can be changed by removal of the provoking foodstuffs from the diet (we will be investigating more on this topic in later blog posts).

• The most common foods provoking ADHD symptoms in the study were beet sugar, food colorings, wheat and milk.

• Frequencies corresponding to eight different brain wave states were obtained in 16 different regions of the brain. A summary of the numerical frequencies of these eight different states (in Hertz, or cycles per second) and their corresponding brain wave types and approximate brain activity levels are listed below:

• Out of all of the frequencies listed above, the beta-1 brainwave frequency was believed to be impacted the most by food allergies. Interestingly, it appears that the beta-1 brainwave frequency changes appeared to be concentrated the most in the right frontal and temporal regions of the brain (keep in mind that the different parts of the brain do not operate at uniform frequencies, for example, some regions may be in a predominantly beta-1 state while others are operating at a theta state). This area is also one of the brain regions most associated with ADHD, as we have seen in earlier posts. An outline of the areas with the greatest change in beta-1 activity is given in the diagram below:
  

The approximate locations of the 16 different brain regions probed for beta-1 brainwave frequency changes in the Uhlig study are given above (as one would see from a top-down view of the head). The larger blue squares indicate brain regions of greatest change in beta-1 activity between the two EEG scans (one after prolonged consumption and the other after prolonged avoidance of allergy-provoking foods). The smaller blue squares indicate regions of smaller (but still statistically significant) changes between the two EEG measurements. The white squares indicate brain regions that saw minimal change in beta-1 activity.

We should also note that the brain regions most affected by food sensitivities also happen to be the same areas most connected to ADHD, as we have seen in previous posts, such as the one on differences in brain region blood flow patterns in ADHD.

• While the Uhlig study showed significant changes in beta-1 activity due to food-sensitivity effects, alpha activity changes were minimal. Other studies have indicated that diseases with reduced blood flow to the brain (which can include ADHD) are more associated with changes in delta and theta brainwave activities. As mentioned in the brainwave chart in this post, theta activity, which is essentially a daydreaming state, is (not surprisingly) seen more consistently in individuals with ADHD than in the general population. On another interesting note, adults with anxiety-type depression have also been shown to exhibit an increase in beta-1 activity in similar brain regions.
  

In this blogger's opinion: The above point suggests that there may be at least two different major causes of ADHD, which are associated with different brainwave states. The "food-sensitivity ADHD", which is associated with beta-1 frequency changes suggests an entirely different mechanism of cause and action than does the "reduced bloodflow ADHD", which is characterized by theta and delta brainwave frequency changes. This, of course, is simply a hypothesis, but looking down the road with regards to diagnostic and treatment measures, we could be using EEG to diagnose whether the underlying cause as to whether someone's ADHD is either the food-sensitivity derived beta state or the reduced bloodflow-derived theta or delta state. In other words, by examining to see whether the beta-1 activity in the front part of the brain or the theta or delta activity is more disrupted, we could possibly use brainwave frequency changes distinguish between multiple underlying causes of ADHD. Of course, this presupposes that brainwave frequency differences are contributing causes of (as opposed to indicators of) ADHD.

There are two key points we should take away from this article:

1. Consumption of foods of which one may have an allergy or sensitivity to can have a huge effect on ADHD symptoms, as we saw from the Conner's rating scale score differences in this post. The fact that most children fell below the threshold score for ADHD when they avoided the provoking foods, but above it when they consistently consumed them should raise an alarm. While the ADHD/food allergy connection has been around for years, the sheer magnitude of the difference in scores (albeit from a smaller sample, which often will produce greater fluctuations in score differences because extreme individual cases stand out more). Of course not all ADHD cases are due to food allergies, but this study should lend credence to the potential effectiveness of eliminating specific foodstuffs (remember that beet sugar was the most common food sensitivity in the study) in treating at least some of the cases. Furthermore, monitoring for changes in beta-1 brainwaves, especially in the brain areas mentioned above via EEG may be an extremely effective tool of the future for diagnosing (and eventually treating) food-related ADHD symptoms.
   
2. The pronounced changes in beta-1 activities highlight the surprisingly strong connection between the digestive system and the nervous system, as changes in conditions in the gut can result in extensive changes in neurological symptoms. We will discuss this connection in greater detail, as well as its implications on ADHD at a later time.
   

read more...

Genes and ADHD Brainwave Patterns

There is mounting evidence surrounding the genetic basis for ADHD. Some studies place the blame on genes, as heritability of ADHD may be as high as 75 percent. Some of the specific ADHD genes under investigation can be seen here.

EEG has been a hot topic of discussion as of late for individuals suffering from attentional difficulties. Short for electroencephalography, EEG is an electrical measuring device used to monitor brainwave patterns and frequencies. In general, the higher the frequencies, the more "alert" the individual is:

Some common states and their EEG ranges can be found below. Note that the numbers are in hertz or cycles/second

Delta: 1-4, sleep
Theta: 5-7, daydreaming
Alpha: 8-12, relaxation (watching TV)
SMR (Sensorimotor Rhythm): 12-15, Focused relaxation, live sporting events, easy video games
Beta: 13-24- concentration
High Beta: over 25-30, anxiety and related symptoms

Individuals with ADD or ADHD often (not surprisingly) have more difficulty staying in the Beta range and are seen excessively in the Theta state. EEG programs are available in which the individual attempts to remain in a beta state for as long as possible. Essentially, they "train" the brain to hold a higher frequency, often through some type of interactive computer game which stops when beta frequencies are no longer maintained.

To be perfectly honest, I know relatively little about the intricacies of this procedure. However, based on what I've gathered so far on the subject, this practice seems to have had a moderate amount of success. Some consider it to be too costly or over-prescribed, while others swear by the results. Based on what I've read, typical treatment is often comprised of weekly interactive EEG treatments for a period of 1-2 years. At this point, I am not in a position to give advice on this alternative treatment measure for ADHD and related disorders, but I do find at least the theory behind it to be highly plausible.

Returning to the genetic basis surrounding EEG measurements for a moment, we see that the degree of heritability is thought to be highest somewhere around the high alpha and low beta states (right around the Sensorimotor Rhythm region mentioned above) and begins to decrease at both higher (high Beta) and lower (Delta and Theta) states. Given the difficulties of achieving a consistent Beta state for ADHD'ers, we can see that these difficulties may fall right in the eye of this storm of heritability and genetic predisposition.

A comparative study was done examining EEG patterns of un-medicated children with ADHD who had siblings or parents with the disorder. This study measured baseline brainwave frequencies and brainwave patterns when the subjects underwent a Continuous Performance Task.

In a nutshell, Continuous Performance Task tests measure both inattention and impulsivity, both of which are landmark ADHD characteristics.

How the Continuous Performance Task test typically works:
An individual may be asked to press a computer button only after seeing a specific letter or shape. If that letter or shape is shown only rarely, then the individual enters a "bored" state (which is often connected to Theta activity, which is typically higher in ADHD individuals to begin with). As a result, he or she may space out and miss when the letter or shape is finally presented on the screen. This "miss" is called an error of omission, and is reflective of inattention.

On the flip side, if the letter or shape is constantly being shown, the individual may attempt to "guess" when it is next displayed and push the response button prematurely. This is an error of commission, and is more connected to impulsivity.

Correlations in EEG patterns between siblings was much higher for measures taken in a state of cognitive activation (i.e. when undergoing the continuous performance task listed above) than EEG baseline patterns. This suggests that ADHD genetic differences are much more pronounced during cognitively challenging situations, than during rest. In other words, similarities in brainwave patterns of ADHD siblings are greater during cognitive tasks than while at rest.

• The only statistically significant EEG pattern seen between siblings at the resting or baseline state was that of the theta state in the frontal region of the brain. This is interesting to note, because this region, which includes a brain domain called the prefrontal cortex, which is thought to be one of the major "hot spots" for chemical imbalances in an ADHD brain.

• During these performance tasks, which involve periods of concentration, it was noted that correlations between sibling brain wave patterns were extremely high; higher than a cause which was purely genetic would indicate (since non-identical twin siblings only share half of the same genetic material). This suggests that among these siblings, both genetics and overlapping environmental factors are both at work.

• While all brain wave states during concentration tasks were thought to be genetically connected, it appears that changes in the alpha state (and somewhat with the theta state)were the most pronounced. This was believed to be due to an overall decrease in these overall frequency states during concentration tasks, which suggests that in order to maintain concentration for a cognitive tasks, the brains of these individuals were forced to work "harder" by operating at a higher frequency (Beta) state. To overstate the obvious, this supports the idea that ADHD brains must work harder to maintain an attention span by bumping up to a higher state.

• One note of particular interest: It appears that genetics (i.e. having at least one parent with the disorder) plays a much greater role in errors of omission (see description near the top of this post) than in errors of commission. Since errors of omission are more associated with inattentive behavior and errors of commission are more associated with impulsive behavior, it suggests that genes are more likely involved in individuals who are more of the predominantly inattentive ADHD subtype than they are for the hyperactive-impulsive ADHD subytpe.

• While genetics appeared to be connected to overlaps in brain wave states and how hard the brains of ADHD siblings had to work to maintain attention, there was little statistical evidence linking actual cognitive task performance to family-based genetic heritability. In other words, while the brains of these children with ADHD had to work harder to complete the cognitive task, the overall abilities to actually perform the task were not thought to be tied to familial inheritance (such as from the parents).

• This above point suggests two things: 1.) Individuals with ADHD are able to over-ride genetic predispositions and maintain an attention span, albeit at a higher cost, and 2.) EEG is a powerful diagnostic tool that is a more accurate predictor of genetic heritability of ADHD than are physically detectable symptoms (such as observed bouts of inattention, hyperactivity or distractibility).

While these findings are encouraging, it is important to note that EEG-based treatment of ADHD is still in a period of relative infancy. However, like the experience of watching a duck on the water (who appears to be calmly floating along while his legs are thrashing below the water's surface) EEG offers the unique ability to detect the "thrashing below the surface" of an ADHD brain. The studies above strongly suggest that there may be a much greater genetic component to this thrashing than we previously expected.

read more...