​A new study published November 2025 investigated the diets and other factors of many people with ADHD in 150 countries over a 28-year period, and found some interesting factors regarding some causes or treatments which can help to reduce ADHD symptoms.

The study acknowledges that food choices and nutrients are critical factors in neurological conditions, and this study looked into the individual macronutrients of protein, carbs and fats with ADHD prevalence and prevalence (Ni, Senior, Raubenheimer, Simpson & Nanan, 2025).

Some of the findings of this study included:
1. Increasing carbohydrates (from sugar, grains, fruits etc) in the diet increases prevalence of ADHD symptoms
2. Increasing dietary fats reduces ADHD symptoms and prevalence, as healthy fats can help with improved nerve function and omega-3 fats can reduce neuro-inflammation which can drive ADHD symptoms
3. Increased plant-based protein actually increased ADHD symptoms and prevalence, probably due to soy protein which is high in phyto-oestrogens which can affect male hormone balance and is known to increase ADHD in other studies. Animal proteins contain a larger range of amino acids which are beneficial in making the neurotransmitters needed for good mental health balance.

In summary, reducing carbohydrates and increasing healthy fats can be protective of ADHD symptoms and can reduce incidences, as can increased animal food based proteins. I have seen similar improvements and reduction of ADHD symptoms in many patients or children who have improved their diets and macronutrient percentages.

Improving the quality and variety of foods can improve nutrient density, reduce nutrient deficiencies, reduce digestive system symptoms which are common in ADHD, reduce food intolerances, reduce inflammation and oxidative damage which can affect brain function, improve sleep, and other health benefits.

Your food choice or nutrition intake isn’t the only driver of ADHD symptoms and mood or emotional dysregulation issues, but it’s a good start! There are many other root causes and factors involved in this complex chronic condition, which can be different in each person, and all root causes and factors need to be identified and addressed in each person in order to get further reduction of symptoms.

If ADHD symptoms can be reduced with changes in your diet, or macronutrient levels, or even with improved levels of vitamins and minerals, then ADHD is not genetic! There can be some genetic predisposition, which this study suggests, but environmental factors such as nutrition, heavy metals, toxins and chemicals, stress and trauma, and more, are modifiable and preventable factors which can be addressed to reduce and even reverse ADHD. There’s a lot which can be done to improve the health and quality of life of people with ADHD (and their families)! This is what I can help you with!

Stay healthy!

References:

​Ni, D., Senior, A., Raubenheimer, D., Simpson, S.J. & Nanan, R. (2025). Food environment with high plant-based fat supply is associated with Attention-Deficit/Hyperactivity Disorder (ADHD) protection: a global study with more than 150 countries. Frontiers in Nutrition. 12:1658228. DOI: 10.3389/fnut.2025.1658228

I’ve come across two published studies which are concerning, but they give some clues and science into the causes and development of Autism conditions (and likely also ADHD).

Both studies looked into the levels of vitamin B12 and folate, being two of the main B-vitamins, in both pregnant women and newborn babies, and the relationship to the development of Autism.

One study (Raghavan et. al., 2018) investigated 1257 mother-child pairs to find out the mother’s multivitamin intake during the pregnancy, and testing blood levels of vitamin B12 and folate in the mother and baby 2-3 days after birth. Approximately 86-90% of women in the study were taking multivitamin supplements. This study found that even low to moderate intake of multivitamin supplementation was associated with an increased risk of Autism development. High blood levels of folate was found to have a 250% increased risk of ASD development. Similarly, very high vitamin B12 levels was also found to be associated with a similar level of ASD development. The highest risk of development of Autism conditions were in mothers who had elevated levels of folate AND vitamin B12.

A second study (Raghavan et. al., 2020) confirmed the previous study’s findings that mothers with high folate levels had a 200% risk of development of Autism and/or ADHD in their babies, but when combined with similarly high vitamin B12 levels, the risk of Autism/ADHD development jumped dramatically to 1,760% compared to mothers with optimal folate and B12 levels. This was confirmed when the baby’s cord blood were analysed, showing when there were high unmetabolised folic acid levels, there was a 200% increase of Autism risk, or 1000% increase in African-American babies. The authors ruled out that the high folate levels were not from natural folate from plant foods, but only from folic acid in supplements and/or fortified or processed foods.

How is this possible, when vitamin B12 and especially folate (as folic acid) are highly recommended and even prescribed by doctors to prevent neural tube defects in babies?

There are a number of reasons for these findings. The main issue is that while vitamin B12 and folate are absolutely essential vitamins for DNA replication, and the growth and development of the foetus and babies, there’s a huge difference between these vitamins in foods vs. in supplements. And some folic acid products being prescribed by doctors contain 10-20 times the normal dose of folate! This can be far too much and exceeds the body’s ability to metabolise the folate and B12, to cause very high and toxic levels of folic acid in the mother’s body (and likely in the foetus too).

Pregnant women, or those trying to conceive, are usually recommended to take a high dose folic acid supplement, either on its own or in a pregnancy multivitamin. But folic acid is not folate!

Folic acid is a completely different and synthetic form of folate, which isn’t found in foods. It’s found in fortified wheat flour by law, and hence in breads and bakery products, processed foods, pasta, and more foods, and often in cheap over the counter multivitamin supplements. Folic acid isn’t metabolised in the same way in your body as natural folate from foods, and is a much slower process. Regular or high doses of folic acid can then build up in the mother and foetus/baby to high levels. This can cause an issue called “Unmetabolised Folic Acid Syndrome”, which can cause a number of symptoms including mental health issues.

Other studies have found that folic acid can actually BLOCK the folate receptors on cell walls, to further slow down the metabolism of natural folate from foods. But because metabolism of folic acid is slower and further exacerbated by folic acid blocking the use of natural folate, the high levels of folate when blood is tested, is actually a functional deficiency of folate! Having a deficiency of folate, even with supplementing and especially from folic acid, can then CAUSE neural tube defects and Autism conditions.

If the mother or baby has any of the MTHFR genetic variants, this can reduce the metabolism of folate even more, to cause higher levels of unmetabolized folic acid which can further contribute to a functional deficiency of folate (and B12) and increase the development of Autism and ADHD conditions.
Similarly to folic acid, there are poorly bioavailable synthetic forms of vitamin B12, especially of cyanocobalamin, which as its name suggests is a cyanide form of vitamin B12, where cyanide is a byproduct of the body’s metabolism of this form of B12. Again it’s a slower metabolic process than natural B12 from animal based foods. Cyanocobalamin is used in cheap retail multivitamin supplements, and should be avoided as should folic acid.

Having functional deficiencies of folate and/or vitamin B12 causes reduced methylation functions in the body, which can increase levels of homocysteine, a toxic metabolic byproduct, which can cause high levels of oxidative damage in the body. The brain and nerves are the most sensitive parts of the body to oxidative damage, which can affect moods, behaviours and mental health. Hence this is another mechanism for folate and B12 deficiencies contributing to the development of ASD conditions.

What’s the solution then?

There are a number of things which can be done to reduce the risks of Autism/ASD/ADHD conditions, but the first is the avoid intake of folic acid in supplements, fortified and processed foods, and avoid the cyanocobalamin form of vitamin B12 too. There are other better and safer forms of these B-vitamins, if supplementation is needed or if dietary intake is inadequate or if the digestive system needs support.
As per other articles I’ve written on Autism, ASD conditions and ADHD, having a folate and/or vitamin B12 deficiency isn’t the only cause or factor in the development of these conditions. But these deficiencies ARE a very common cause in ASD conditions, in my clinical experience. It would be very rare for a child, teen or adult with Autism or ASD conditions or ADHD to not be deficient in folate and/or vitamin B12 in their diet, or blood test results showing them as not being deficient in these important B-vitamins, or having very high levels which suggests that their use is being blocked to cause the same symptoms as a deficiency.

If someone has Autism or ADHD, the information and findings from these studies suggests that the incidences of Autism conditions could be reduced and prevented with better forms of these essential B-vitamins, especially in pre-conception or during, or even that symptoms in those with Autism/ADHD conditions could be reduced to improve their mental health and quality of life!

These studies show the importance of getting tested for B-vitamin status prior to trying to conceive and get pregnant, as well as during the pregnancy, and getting good nutritional advice from experts (ie, NOT from doctors), and using better forms of the B-vitamins or pregnancy supplements during these times.
Stay healthy!

References:

Raghavan, R., Riley, A. W., Volk, H., Caruso, D., Hironaka, L., Sices, L., Hong, X., Wang, G., Ji, Y., Brucato, M., Wahl, A., Stivers, T., Pearson, C., Zuckerman, B., Stuart, E. A., Landa, R., Fallin, M. D., & Wang, X. (2018). Maternal Multivitamin Intake, Plasma Folate and Vitamin B12 Levels and Autism Spectrum Disorder Risk in Offspring. Paediatric and perinatal epidemiology, 32(1), 100–111. DOI: 10.1111/ppe.12414

​Raghavan, R., Selhub, J., Paul, L., Ji, Y., Wang, G., Hong, X., Zuckerman, B., Fallin, M. D., & Wang, X. (2020). A prospective birth cohort study on cord blood folate subtypes and risk of autism spectrum disorder. The American journal of clinical nutrition, 112(5), 1304–1317. DOI: 10.1093/ajcn/nqaa208

A lot of people with Autism/ADHD have sensitivity issues which can affect their physical health, mental health, body functions, and quality of life. This is quite a common finding I see in clinical practice. Sometimes health issues like sensitivities can have a very simple explanation and a very simple solution!

A sensitivity, as the name suggests, is related to your senses, such as of smell and taste, and more. People often refer the sensitivities as “intolerances” which is not the same thing. The sensitivities result from internal reactions to external sources, through our senses.

People with Autism/ADHD and related conditions can often have sensitivities to:

- Sight, including of sunlight and bright light – causing watery eyes, irritation, headaches and migraines, and the need to wear sunglasses, which causes even more health issues (but that’s a topic for another article!)
- Smells – of strong smells causing irritation, runny nose, headaches and migraines, and nausea or even vomiting (including morning sickness!)
- Sounds – loud noises causing shock and stress, ear pain, tinnitus (annoying ringing in the ears) and more
- Touch – of physical touching, or irritation to different fabrics, materials and surfaces, tight-fitting clothes, and tags on clothes, shoes etc
- Taste – changes in the taste of foods, of either no taste, or being repulsed by the taste of foods, and even the feeling of textures of foods can be off-putting and causing food restrictions (and nutrient deficiencies)
- Alcohol – having a stronger and quicker response to alcohol than others
- Medications - having a stronger and quicker response to some medications than others
- Emotional sensitivities – responding quickly and excessively to even minor stresses or emotions.

This is why I always ask questions about sensitivity issues in my initial consultations with patients! The more and stronger the sensitivities there are in someone, it gives me big clues as to what might be causing their sensitivities and other symptoms too.

Sensitivities are much more prevalent and severe in people with ASD and ADHD, and often affecting more than one of their senses. Typical sensitivities in ASD/ADHD include being sensitive to the sun or light (and preferring to be in the dark), a poor sense of taste and smell, or hyper-reacting to tastes and smells, sensitive to loud or sudden noises such as in schools or shopping centres, food texture issues preventing eating of many foods, and other reactions.

The over-stimulation of the senses bombards the nerves and the nervous system (Attitude Mag, 2025). This in turn causes so much information being sent to the brain and overloads it, causing an inability to concentrate or focus on important tasks, the person becoming overwhelmed quickly, and having an initial feeling of plenty of energy (seen as hyperactivity) but burning out quickly to fatigue. Combine this hyperstimulation with an inability to calm, and you have many of the characteristics of ASD/ADHD!

The sensory overload to the brain can also contribute to the inability to calm the brain and nervous system, and can often be diagnosed as Sensory Processing Disorder, another common co-morbid diagnosis in many people with Autism/ADHD.

It's not particularly well known that ONE major nutrient deficiency can affect all our senses! This nutrient deficiency can cause dysfunction in our senses, from reduced function to hypersensitivity.

That nutrient deficiency is the essential mineral of zinc!

Of course, zinc isn’t the only nutrient deficiency in ASD/ADHD, but it is extremely common in these conditions, and it has a huge impact on ASD/ADHD symptoms. For example, a zinc deficiency can cause other Autism/ADHD symptoms including:

1. Affecting stomach function – to cause reduced digestion. And leading to reduced nutrient absorption and other nutrient deficiencies. This can also lead to digestive symptoms of reflux, indigestion, heartburn, gas, bloating, and constipation or diarrhoea
2. Anaemia and iron deficiency – zinc is needed for protein metabolism and iron metabolism. Anaemia is extremely common in those with ASD/ADHD in approximately 80% of cases in my experience
3. Neurotransmitter and hormone imbalances – zinc is needed to make the neurotransmitters and other hormones too, therefore low zinc can affect moods and behaviours and mental health
4. Sleep issues – zinc is needed to make melatonin, the sleep hormone, hence a zinc deficiency can affect sleep
5. Skin issues and joint issues– zinc is needed for skin and connective tissue with collagen production. Low zinc can cause poor skin integrity, rashes and lesions, growing pains, hypermobile joints, all common with ASD/ADHD
6. Low immune system function – zinc is needed for production of the white blood cells for your immune system and protection from infections. Low zinc causes reduced immunity and increased or more frequent infections
7. Thyroid function – zinc is needed for optimal thyroid function and to make the thyroid hormones which control your whole body’s metabolic rate and all organ and cell functions. It’s very common to see many people with ASD/ADHD with low functioning thyroid, and this causing a lot of their symptoms.

​Correcting a zinc deficiency can therefore reduce all of these issues, and give other benefits to your health too, and can greatly reduce the Autism/ADHD symptoms.

This should be the biggest shock to people with Autism/ADHD or parents of children with these conditions. Or one of the biggest omissions in testing or treatment for people and children with Autism/ADHD.

But you can’t or shouldn’t just go out and get some zinc if you have ASD or ADHD! You need to get this tested first, along with other blood tests which are related to low zinc levels, such as checking for anaemia and immune function, iron levels, thyroid function, stomach function, and more. This will help with getting a baseline of your zinc levels to check against later, as well as helping with your likely dosing needs.

There are also some tricks with taking zinc, such as the therapeutic doses, the forms or types of zinc (ie zinc oxide, zinc picolinate, zinc citrate, zinc amino acid chelate, or others) and/or from foods, as some of these forms are useless and not bio-available, and some are much better! The timing and dosing of the zinc is very important to reduce possible side effects.

This is where I can help, with recommending specific testing first, and dietary improvements, and improving digestive system function, and recommending the right form of zinc and dosing for each person.
More more info on this website, including the Bookings page, where I can help you in your journey to reducing your symptoms and improving your health!

References:
Attitude Mag. (2025). My Hypersensitivity Is Real: Why Highly Sensitive People Have ADHD. Retrieved 5th November 2025 from

Part 1 of Autism/ADHD and MTHFR:

On the genetics topic again with Autism and ADHD, to explain why these conditions are mostly nothing to do with them being caused by genetics, and why there are always other factors which cause Autism/ADHD or contribute to their presentation and symptoms.

You may or may not have heard of the MTHFR gene. This is an acronym for Methylene Tetra Hydro Folate Reductase, which is a gene we all have, and in turn produces a protein/enzyme in the body, also called MTHFR. This enzyme is needed for the metabolism of folate (vitamin B9) from its inactive form in foods into the active form of folate, called methylfolate, so your body can use it.

A large percentage of the population, approximately 40%, have a variant to one or both of the main types of MTHFR genes. This is NOT a genetic mutation at all, as mutations are changes to genes being different to what your parents had, or a genetic change within your lifetime, typically due to viruses, chemical toxicities, or radiation. A genetic variant is often a historical change or difference to a gene which is not “normal”, usually due to a single DNA building block/protein being replaced by another. These variants can be passed onto children and their children.

Two of the main MTHFR gene variants occur to the MTHFR C677T and A1298C genes.

The MTHFR genes are also related to energy production, genetic expression, production of neurotransmitters for good mental health balance, and detoxification. Hence any variant to the MTHFR genes can have a minor, moderate or even a severe impact on these body functions. All of these functions are typically compromised in people with Autism/ADHD.

But why are Autism/ADHD conditions not genetic, if they can be related to genetic variants to the MTHFR genes?!

Because of epigenetics. This is the science of how your environmental factors can interact with your genes to turn them on or turn them off to contribute to your health or to cause disease symptoms and conditions. Hence you may have a genetic predisposition to certain symptoms or health issues, but only if triggered by your epigenetic/environmental factors. These include stress, toxicities, poor sleep, nutrient deficiencies, inflammation and oxidative damage, and more. Or if you do all the right things and reduce these factors, even though you might have the genetic variants and their predisposition to symptoms, you can effectively turn off the genetic variants and reduce or eliminate your risk of their related symptoms and conditions.

Hence your epigenetic/environmental factors are far more responsible for your health (or your symptoms and conditions) than your genetics alone! This is why Autism/ADHD is not normal at all, not caused by genetics alone, and why when the epigenetic/environmental factors or triggers are reduced, avoided or fixed, the symptoms and conditions of Autism/ADHD can reduce, or be cleared and reversed.

You can test for your MTHFR status with a genetic test, which reports on whether you have none, one or both variants of the MTHFR gene, and also whether you have one or both copies of the variation from both your parents. However, there are limitations to getting the MTHFR genetic test, with one being that it’s not the only test which is needed to be done to find the causes or results of the MTHFR variant contributing to your health issues. The tests needed can differ from person to person, depending on your symptoms and conditions. However, this is something that I can help you with.

See my follow up this article on this topic, with part 2 on issues with the MTHFR variants and Autism/ADHD.

This is Part 2 of my article on MTHFR and Autism/ADHD:
​
This article follows on from my previous article on the MTHFR gene and its relationship to Autism and ADHD conditions.

Many published studies show the links between having the MTHFR genetic variants and Autism/ADHD symptoms and conditions, for a number of reasons:

1. Having an MTHFR variant can cause a functional deficiency of folate, which in turn can affect the metabolism of other vitamins such as B12, B6 and others, thus potentially causing a number of nutrient deficiencies and their related deficiency symptoms
2. MTHFR metabolic issues can affect energy levels, to cause weakness, fatigue, brain fog, poor memory and concentration, which are common in Autism/ADHD
3. MTHFR issues affect the production of hormones and neurotransmitters, to cause mood and behaviour changes, and other mental health symptoms such as depression, anxiety, anger and violence and more
4. MTHFR variants can affect detoxification functions, and causing increased toxicity, which can affect brain function to affect moods and behaviours and mental health
5. MTHFR variants reduce the ability of the body to metabolise homocysteine, resulting in increased inflammation and oxidative stress in the body, which in turn affects moods and behaviours and mental health
6. Some MTHFR variants, specifically the C677T variant, are associated with the increased risk of Autism disorders, Bipolar Disorder and Schizophrenia (Li et. al., 2020; Meng et. al., 2022), being serious neurological disorders which are commonly seen along with Autism/ADHD
7. The MTHFR A1298C variant is also related to Bipolar Disorder and ADHD, but not Autism disorders
8. Some MTHFR variants can increase the risks of, or worsen, heart and circulation issues.

Studies show that there is a link to having the MTHFR variants with these neurodevelopmental and neurological conditions, which includes Autism and ADHD, and therefore related to the metabolism of folate (and vitamin B12, B6 and others) (Meng et. al., 2022). Folate from foods, which the MTHFR gene metabolises, is needed for the development and function of the nervous system and the brain, hence the importance of your foods and nutrition for preventing and even treating Autism/ADHD! Or on the other hand, poor food choices and nutrient deficiencies can contribute to mental health symptoms and Autism/ADHD. Folate is particularly needed for DNA replication when cells divide and create new cells during periods of growth and development, especially in pregnancy for a foetus, or in the growing childhood years.

Sadly a common recommendation from doctors is for women who are trying to conceive, or pregnant women, to take high doses of folic acid to prevent neural tube defects such as spina bifida, without actually checking the MTHFR genetic status of the woman first. Folic acid is NOT the same as folate from foods!

Folic acid is the synthetic form of folate in all non-organic wheat flour based products, processed foods, and in cheap (and nasty) supplements. Metabolising folic acid in the body is a much slower process than from natural folate in foods, which can create a deficiency of methylfolate (the active form the body uses) when it’s needed. If you have any of the MTHFR genetic variants, this will compound the problem of metabolising folic acid (and natural folate), to further slow down the body’s use of methylfolate, creating more of an issue of a deficiency of methylfolate, and leading to its related symptoms. Even worse, is that folic acid from wheat flour products, processed foods and supplements, can actually BLOCK the folate receptors on the cells, to even further slow down the ability of cells to use the methylfolate. Hence folic acid can make MTHFR related symptoms and conditions MUCH worse, including in those with Autism/ADHD and related other conditions.

But what do children and people with Autism/ADHD like to eat?! Lots and lots of beige foods of breads, bakery products, pasta, cereals, wheat flour crumbed chicken nuggets, and processed foods – ALL very high in folic acid! And you wonder why they have mood and behaviour issues, mental health symptoms, and Autism/ADHD.

Folic acid isn’t just a problem in children or people with MTHFR genetic variants, or with Autism/ADHD. Folic acid still slows down the metabolism of natural folate in everyone, but having an MTHFR issue makes it several times worse.

Folic acid must really be avoided by everyone!

There are, of course, other causative factors to Autism/ADHD conditions than someone’s MTHFR status. But having an MTHFR variant can contribute in many ways to the mood and behaviour issues and other symptoms of Autism/ADHD.

Stay healthy!

References:

Li, Y., Qiu, S., Shi, J., Guo, Y., Li, Z., Cheng, Y., & Liu, Y. (2020). Association between MTHFR C677T/A1298C and susceptibility to autism spectrum disorders: a meta-analysis. BMC Pediatrics, 20, 449. DOI: 10.1186/s12887-020-02330-3

Meng, X., Zheng, J. L., Sun, M. L., Lai, H. Y., Wang, B. J., Yao, J., & Wang, H. (2022). Association between MTHFR (677C>T and 1298A>C) polymorphisms and psychiatric disorder: A meta-analysis. PloS one, 17 (7), e0271170. DOI: 10.1371/journal.pone.0271170