top of page

Reflections on the increase in Autism, ADHD, anxiety and depression: Part 2- Exposure to neurotoxins and ultra-processed foods

Posted: June 30, 2024 | Author: erikpeper

Adapted from: Peper, E. & Shuford, J. (2024). Reflections on the increase in Autism, ADHD, anxiety and depression: Part 2- Exposure to neurotoxins and ultra-processed foods. NeuroRegulation, 11(2), 219–228.

Published with the permission of Dr Erik Pepper

Look at your hand and remember that every cell in your body including your brain is constructed out the foods you ingested. If you ingested inferior foods (raw materials to be built your physical structure), then the structure can only be inferior. If you use superior foods, you have the opportunity to create a superior structure which provides the opportunity for superior functioning.                                        -Erik Peper


Mental health symptoms of attention deficit hyperactivity disorder (ADHD), Autism, anxiety and depression have increased over the last 15 years. An additional risk factor that may affect mental and physical health is the foods we eat.  Even though, our food may look and even taste the same as compared to 50 years ago, it contains herbicide and pesticide residues and often consist of ultra-processed foods. These foods (low in fiber, and high in sugar, animal fats and additives) are a significant part of the American diet and correlate with higher levels of inattention and hyperactivity in children with ADHD. Due to affluent malnutrition, many children are deficient in essential vitamins and minerals. We recommend that before beginning neurofeedback and behavioral treatments, diet and lifestyle are assessed (we call this Grandmother therapy assessment). If the diet appears low in organic foods and vegetable, high in ultra-processed foods and drinks, then nutritional deficiencies should be assessed. Then the next intervention step is to reduce the nutritional deficiencies and implement diet changes from ultra-processed foods to organic whole foods. Meta-analysis demonstrates that providing supplements such as Vitamin D, etc. and reducing simple carbohydrates and sugars and eating more vegetables, fruits and healthy fats during regular meals can ameliorate the symptoms and promote health.

The previous article, Reflections on the increase in Autism, ADHD, anxiety and depression: Part 1-bonding, screen time, and circadian rhythms, pointed out how the changes in bonding, screen time and circadian rhythms affected physical and mental health (Peper, 2023). However, there are many additional factors including genetics that may contribute to the increase is ADHD, autism, anxiety, depression, allergies and autoimmune illnesses (Swatzyna et al., 2018). Genetics contribute to the risk of attention deficit hyperactivity disorder (ADHD); since, family, twin, and adoption studies have reported that ADHD runs in families (Durukan et al., 2018; Faraone & Larsson, 2019).  Genetics is in most cases a risk factor that may or may not be expressed.  The concept underlying this blog is that genetics loads the gun and environment and behavior pulls the trigger as shown in Figure 1.

Figure 1. Interaction between Genetics and Environment

The pandemic only escalated trends that already was occurring. For example, Bommersbach  et al (2023) analyzed the national trends in mental health-related emergency department visits among USA youth, 2011-2021. They observed that in the USA, Over the last 10 years, the proportion of pediatric ED visits for mental health reasons has approximately doubled, including a 5-fold increase in suicide-related visits.  The mental health-related emergency department visits increased an average of 8% per year while suicide related visits increased 23.1% per year. Similar trends have reported by Braghieri et al (2022) from the National Survey on Drug Use and Health as shown in Figure 2.

Figure 2. Mental health trends in the United States by age group in 2008–2019. The data come from the National Survey on Drug Use and Health. Reproduced with permission from Braghieri, Luca and Levy, Ro’ee and Makarin, Alexey, Social Media and Mental Health (July 28, 2022) or

The trends reported from this data shows an increase in mental health illnesses for young people ages 18-23 and 24-29 and no changes for the older groups which could be correlated with the release of the first iPhone 2G on June 29, 2007. Thus, the Covid 19 pandemic and social isolation were not THE CAUSE but an escalation of an ongoing trend. For the younger population, the cellphone has become the vehicle for personal communication and social connections, many young people communicate more with texting than in-person and spent hours on screens which impact sleep (Peper, 2023). At the same time, there are many other concurrent factors that may contributed to increase of ADHD, autism, anxiety, depression, allergies and autoimmune illnesses.

Without ever signing an informed consent form, we all have participated in lifestyle and environmental changes that differ from that evolved through the process of evolutionary natural selection and promoted survival of the human species.  Many of those changes in lifestyle are driven by demand for short-term corporate profits over long-term health of the population. As exemplified by the significant increase in vaping in young people as a covert strategy to increase smoking (CDC, 2023) or the marketing of ultra-processed foods (van Tulleken, 2023).  

This post focusses how pesticides and herbicides (exposure to neurotoxins) and changes in our food negatively affects our health and well-being and is may be another contributor to the increase risk for developing ADHD, autism, anxiety and depression.  Although our food may look and even taste the same compared to 50 years ago, it is now different–more herbicide and pesticide residues and  is often ultra-processed. lt contains lower levels of nutrients and vitamins such as Vitamin C, Vitamin B2, Protein, Iron, Calcium and Phosphorus than 50 years ago (Davis et al, 2004; Fernandez-Cornejo et al., 2014). Non-organic foods as compared to organic foods may reduce longevity, fertility and survival after fasting (Chhabra et al., 2013).

Being poisoned by pesticide and herbicide residues in food

Almost all foods, except those labeled organic, are contaminated with pesticides and herbicides.  The United States Department of Agriculture reported that “Pesticide use more than tripled between 1960 and 1981. Herbicide use increased more than tenfold (from 35 to 478 million pounds) as more U.S. farmers began to treat their fields with these chemicals” (Fernandez-Cornejo, et al., 2013, p 11). The increase in herbicides and pesticides is correlated with a significant deterioration of health in the United States (Swanson, et al., 2014 as illustrated in the following Figure 3.  

Figure 3. Correlation between Disease Prevalence and Glyphosate Applications (reproduced with permission from Swanson et al., 2014.

Although correlation is not causation and similar relationships could be plotted by correlating consumption of ultra-refined foods, antibiotic use, decrease in physical activity, increase in computer, cellphone and social media use, etc.; nevertheless, it may suggest a causal relationship. Most pesticides and herbicides are neurotoxins and can accumulate in the person over time this could affect physical and mental health (Bjørling-Poulsen et al., 2008; Arab & Mostaflou, 2022). Even though the United States Environmental Protection Agency (EPA) has determined that the residual concentrations in foods are safe, their long-term safety has not been well established (Leoci & Ruberti, 2021). Other countries, especially those in which agribusiness has less power to affect legislation thorough lobbying, and utilize  the research findings from studies not funded by agribusiness, have come to different conclusions…  

For example, the USA allows much higher residues of pesticides such as, Round-Up, with a toxic ingredient glyphosate (0.7 parts per million) in foods than European countries (0.01 parts per million) (Wahab et al., 2022; EPA, 2023; European Commission, 2023) as is graphically illustrated in figure

Figure 4: Percent of Crops Sprayed with Glyphosate and Allowable Glyphosate Levels in the USA versus the EU

The USA allows this higher exposure than the European Union even though about half of the human gut microbiota are vulnerable to glyphosate exposure (Puigbo et al., 2022). The negative effects most likely would be more harmful in a rapidly growing infant than for an adult.  Most likely, some individuals are more vulnerable than others and are the “canary in mine.” They are the early indicators for possible low-level long-term harm.  Research has shown that fetal exposure from the mother (gestational exposure) is associated with an increase in behaviors related to attention-deficit/hyperactivity disorders and executive function in the child when they are 7 to 12 years old (Sagiv et al., 2021).  Also, organophosphate exposure is correlated with ADHD prevalence in children (Bouchard et al., 2010). We hypothesize this exposure is one of the co-factors that have contributed to the decrease in mental health of adults 18 to 29 years. 

At the same time as herbicides and pesticides acreage usage has increased, ultra-processed food have become a major part of the American diet (van Tulleken, 2023). Eating a diet high in ultra-processed foods, low in fiber, high sugar, animal fats  and additives has been associated with higher levels of inattention and hyperactivity in children with ADHD; namely, high consumption of sugar, candy, cola beverages, and non-cola soft drinks and low consumption of fatty fish were also associated with a higher prevalence of ADHD diagnosis (Ríos-Hernández et al., 2017).

In international studies, less nutritional eating behaviors were observed in ADHD risk group as compared to the normal group (Ryu et al., 2022). Artificial food colors and additives are also a public health issue and appear to increase the risk of hyperactive behavior (Arnold et al., 2012).  In a randomized double-blinded, placebo controlled trial 3 and 8/9 year old children had an increase in hyperactive behavior for those whose diet included extra additives (McCann et al., 2007).  The risk may occur during fetal development since poor prenatal maternal is a critical factor in the infants neurodevelopment and is associated with an increased probability of developing ADHD and autism (Zhong et al., 2020; Mengying et al., 2016).

Poor nutrition even affects your unborn grandchild

Poor nutrition not only affects the mother and the developing fetus through epigenetic changes, it also impacts the developing eggs in the ovary of the fetus that can become the future granddaughter (Wilson, 2015). At birth, the baby has all of her eggs.  Thus, there is a scientific basis for the old wives tale that curses may skip a generation. Providing maternal support is even more important since it affects the new born and the future grandchild. The risk may even begin a generation earlier since the grandmother’s poor nutrition as well as stress causes epigenetic changes in the fetus eggs. Thus 50% of the chromosomes of the grandchild were impacted epigenetically by the mother’s and  grandmother’s dietary and health status .

Highly processed foods

Highly refined foods have been processed to remove many of their nutrients. These foods includes white bread, white rice, pasta, and sugary drinks and almost all the fast foods and snacks. These foods are low in fiber, vitamins, and minerals, and they are high in sugars, unhealthy fats, and calories. In addition, additives may have been added to maximize taste and mouth feel and implicitly encourage addiction to these foods. A diet high in refined sugars and carbohydrates increases the risk of diabetes and can worsen the symptoms of ADHD, autism, depression, anxiety and increase metabolic disease and diabetes (Woo et al., 2014; Lustig, 2021; van Tulleken, 2023). Del-Ponte et al. (2019) noted that a diet high in refined sugar and saturated fat increased the risk of symptoms of ADHD, whereas a healthy diet, characterized by high consumption of fruits and vegetables, would protect against the symptoms.

Most likely, a diet of highly refined foods may cause blood sugar to spike and crash, which can lead to mood swings, irritability, anxiety, depression and cognitive decline  and often labeled as “hangryness” (the combination of anger and hunger) (Gomes et al., 2023; Barr et al., 2019). At the same time a Mediterranean diet improves depression significantly more than the befriending control group (Bayles et al., 2022).  In addition, refined foods are low in essential vitamins and minerals as well as fiber. Not enough fiber can slow down digestion, affect the human biome, and makes it harder for the body to absorb nutrients. This can lead to nutrient deficiencies, which can contribute to the symptoms of ADHD, autism, depression, and anxiety. Foods do impact our mental and physical health as illustrated by foods that tend to reduce depression (LaChance & Ramsey, 2018; MacInerney et al., 2017). By providing appropriate micronutrients such as minerals (Iron, Magnesium Zinc), vitamins (B6, B12, B9 and D), Omega 3s (Phosphatidylserine) and changing our diet, ADHD symptoms can be ameliorated.

Many children with ADHD, anxiety, depression are low on essential vitamins and minerals.  For example, low levels of Omega-3 fatty acids and vitamin D may be caused by eating ultra-refined foods, fast foods, and drinking soft drink. At the same time, the children are sitting more in indoors in front of the screen and thereby have lower sun exposure that is necessary for the vitamin D production.

“Because of lifestyle changes and sunscreen use, about 42% of Americans are deficient in vitamin D. Among children between 1 to 11 years old, an estimated 15% have vitamin D deficiency. And researchers have found that 17% of adolescents and 32% of young adults were deficient in vitamin D.” (Porto and Abu-Alreesh, 2022).

Reduced sun exposure is even more relevant for people of color (and older people); since, their darker skin (increased melanin) protects them from ultraviolet light damage but at the same time reduces the skins production of vitamin D.  Northern Europeans were aware of the link between sun exposure and vitamin D production.  To prevent rickets (a disease caused by vitamin D deficiency) and reduce upper respiratory tract infections the children were given a tablespoon of cod liver oil to swallow (Linday, 2010).  Cod liver oil, although not always liked by children, is more nutritious than just taking a Vitamin D supplements. It is a whole food and a rich source of vitamin A and D as well as containing a variety of Omega 3 fatty acids (eicosapentaenoic acid (EPA) (USDA, 2019).

Research studies suggest that ADHD can be ameliorated with nutrients, and herbs supplements (Henry & CNS, 2023). Table 1 summarizes some of the nutritional deficits observed and the reduction of ADHD symptoms when nutritional supplements were given (adapted from Henry, 2023; Henry & CNS, 2023). 

Nutritional deficits observed in people with ADHD

Decrease in ADHD symptoms with nutritional supplements

Vitamin D: In meta-analysis with a total number of 11,324 children, all eight trials reported significantly lower serum concentrations of 25(OH)D in patients diagnosed with ADHD compared to healthy controls. (Kotsi et al, 2019)

After 8 weeks children receiving vitamin D (50,000 IU/week) plus magnesium (6 mg/kg/day) showed a significant reduction in emotional problems as observed in a randomized, double blind, placebo-controlled clinical trial (Hemamy et al., 2021).

Iron:  In meta-analysis lower serum ferritin was associated with ADHD in children (Wang et al., 2017) and the mean serum ferritin levels are lower in the children with ADHD than in the controls (Konofal et al., 2004).

After 12 weeks of supplementation with Iron (ferrous sulfate) in double-blind, randomized placebo-controlled clinical trial, clinical trials  symptoms of in children with ADHD as compared to controls were reduced (Tohidi et al., 2021Pongpitakdamrong et all, 2022).

Omega 3’s: Children with ADHD are more likely to be deficient in omega 3’s than children without ADHD (Chang et al., 2017).

Adding Omega-3 supplements to their diet resulted in an improvement in hyperactivity, impulsivity, learning, reading and short term memory as compared to controls in 16 randomized controlled trials including 1514 children and young adults with ADHD (Derbyshire, 2017)

Magnesium: In meta-analysis, subjects with ADHD had  lower serum magnesium levels compared with to their healthy controls  (Effatpahah et al., 2019)  

8 weeks of supplementation with Vitamin D and magnesium caused a significant decrease in children with conduct problems, social problems, and anxiety/shy scores (Hemamy et al., 2020).

Vitamin B2, B6, B9  and B12deficiency has been found in many patients with Attention Deficit and Hyperactivity Disorder (Landaas et al, 2016; Unal et al., 2019).

Vitamin therapy appears to reduce symptoms of ADHD and ASD (Poudineh et al., 2023; Unal et al., 2019). An 8 weeks supplementing with Vitamin B6 and magnesium decreased hyperactivity and hyperemotivity/aggressiveness.  When supplementation was stopped, clinical symptoms of the disease reappeared in few weeks (Mousain-Bosc et al., 2006).

Table 1. Examples of vitamin and mineral deficiencies associated with symptoms of ADHD and supplementation to reduction of ADHD symptoms.

Supplementation of vitamins and minerals in many cases consisted of more than one single vitamin or mineral. For an in-depth analysis and presentation, see the superb webinar by Henry & CNS (2023):  (Henry & CNS, 2023).

Whole foods are more than the sum of individual parts (the identified individual constituents/nutrients). The process of digestion is much more complicated than ingesting simple foods with added vitamins or minerals.  Digestion is the interaction of many food components (many of which we have not identified) which interact and affect the human biome. A simple added nutrient can help; however, eating whole organic foods it most likely be healthier.  For example, whole-wheat flour is much more nutritious. Whole wheat is rich in vitamins B-1, B-3, B-5, riboflavin, folate well as fiber while refined white flour has been bleached and stripped of fiber and nutrients to which some added vitamins and iron are added.


When working with clients, follow Talib’s principles as outlined in Part 1 by Peper (2023) which suggests that to improve health first remove the unnatural which in this case are the ultra-processed foods, simple carbohydrates, exposure to pesticides and herbicides (Taleb, 2014). The approach is beneficial for prevention and treatment. This recommendation to optimize health is both very simple and very challenging. The simple recommendation is to eat only organic foods and as much variety as possible as recommended by Professor Michael Pollan in his books, Omnivore’s Dilemma: A Natural History of Four Meals and Food Rules  (Pollan, 2006; Pollan, 2011).

Do not eat foods that contain herbicides and pesticide residues or are ultra-processed.   Although organic foods especially vegetable and fruits are often much more expensive, you have choice: You can pay more now to optimize health or pay later to treat disease. Be safe and not sorry.  This recommendation is similar to the quote, “Let food be thy medicine and medicine be thy food,” that has been attributed falsely since the 1970s to Hippocrates, the Greek founder of western medicine (5th Century, BC) (Cardenas, 2013).

There are many factors that interfere with implementing these suggestions; since, numerous people live in food deserts (no easy access to healthy unprocessed foods ) or food swamps (a plethora of fast food outlets) and  54 million Americans are food insecure (Ney, 2022). In addition, we and our parents have been programmed by the food industry advertising to eat the ultra- processed foods and may no longer know how to prepare healthy foods such as exemplified by a Mediterranean diet. Recent research by Bayles et al (2022) has shown that eating a Mediterranean diet improves depression significantly more than the befriending control group. In addition, highly processed foods and snacks are omnipresent, often addictive and more economical.

Remember that clients are individuals and almost all research findings are based upon group averages. Even when the data implies that a certain intervention is highly successful, there are always some participants for whom it is very beneficial and some for whom it is ineffective or even harmful.  Thus, interventions need to be individualized for which there is usually only very limited data. In most cases, the original studies did not identify the characteristics of those who were highly successful or those who were unsuccessful.  In addition, when working with specific individuals with ADHD, anxiety, depression, etc. there are multiple possible causes.  

Before beginning specific clinical treatment such as neurofeedback and/or medication, we recommend the following:

  1.  “Grandmother assessment” that includes and assessment of screen time, physical activity, outdoor sun exposure, sleep rhythm as outlined in Part 1 by Peper (2023). Then follow-up with a dietary assessment that investigates the prevalence of organic/non organic foods, ingestion of fast foods, ultra-processed foods, soft drinks, high simple carbohydrate and sugar, salty/sugary/fatty snacks, fruits, vegetables, and eating patterns (eating  with  family or by themselves in front of screens). Be sure to include an assessment of emotional reactivity and frequency of irritability and “hangryness”.

  2. If the assessment suggest low level of organic whole foods and predominance of ultra- refined foods, it may be possible that the person is deficient in vitamins and minerals. Recommend that the child is tested for the vitamin deficiencies. If vitamin deficiencies identified, recommend to supplement the diet with the necessary vitamins and mineral and encourage eating foods that naturally include these substances (Henry & CNS, 2023). If there is a high level of emotional reactivity and “hangryness,” a possible contributing factor could be hypoglycemic rebound from a high simple carbohydrate (sugar) intake or not eating breakfast combined with hyperventilation (Engel et al., 1947; Barr et al., 2019). Recommend eliminating   simple carbohydrate breakfast and fast food snacks and substitute organic foods that include complex carbohydrates, protein, fats, vegetables and fruit. Be sure to eat breakfast.

  3. Implement “Grandmother Therapy”. Encourage the family and child to change their diet to eating a whide variety of organic foods (vegetables, fruits, some fish, meat and possibly dairy) and eliminate simple carbohydrates and sugars.  This diet will tend to reduce nutritional deficits and may eliminate the need for supplements. 

  4. Concurrent with the stabilization of the physiology begin psychophysiological treatment strategies such as neurofeedback biofeedback and cognitive behavior therapy.

22 views0 comments


bottom of page