Issues with neurodevelopment are on the rise, and it looks like our modern environment could be at least part of the cause. In fact, a recent article in one of the world’s most respected medical journals ‘The Lancet’ talks about a ‘pandemic of developmental neurotoxicity’ in our modern times. So, in this article we look at what some of the common issues that arise when brain development gets ‘pushed off course’ by some of these ‘toxins’, what the latest science suggests are some of the main culprits and where they are most commonly found:

What is developmental neurotoxicity? These are factors that can cause alterations in the development of a child’s brain during the period of rapid early development.

‘Disorders of neurobehavioural development affect 10-15% of all births and the prevalence of rates of Autism Spectrum Disorder, Attention Deficit Disorder seem to be increasing worldwide…Strong evidence exists that industrial chemicals widely disseminated in the environment are important contributors to what we have called the global silent pandemic of neurodevelopmental toxicity.’ (1)

Main question is: how can you reduce the risks of disruption when it comes to brain development?

The first starting point is to understand what the issue is and where the greatest risks come from:

As always, the root causes of these issues are only partly understood. However, we do know that it is not entirely down to genetics and ‘although genetic factors play a role, they cannot explain recent increases in reported prevalence and none of the genes discovered so far seem to be responsible for more than a small proportion of the cases.’ (1)

Once again, our friend Epigenetics (where the environment switches on or off parts of our genetic code) looks to be playing a contributing role with certain environmental factors or more specifically industrial chemicals being more powerful than others:

‘Overall, genetic factors seem to account for no more than perhaps 30-40% of all cases of neurodevelopmental disorders. Thus, non-genetic, environmental exposures are involved in causation, in some cases probably by interacting with genetically inherited predispositions.’ (1)

A developing brain is particularly vulnerable:

Taking a step back, the time of most rapid and fundamental development is from conception to early childhood. So, it makes sense that this is the time of greatest vulnerability. The science backs this up:

‘During these sensitive life stages, chemicals can cause permanent brain injury at low levels of exposure that would have little or no adverse effect in an adult.’ (1)

How and why?

Although the placenta provides some protection, research shows that the placenta does not block the passage of many environmental toxicants. Further, more than 200 foreign chemicals have been detected in umbilical cord blood and breastmilk.

Additionally, the blood brain barrier (which protects the brain) provides only partial protection against the entry of chemicals into the central nervous system.

MRI scans from individuals prenatally exposed to excess amounts of methylmercury have shown evidence of changes in brain function. (1)

So which chemicals are the worst offenders?

Knowing our enemy (or some of them at least!) is always the first port of call. The research published in the Lancet came in two parts over several years. The first part (from 2006) documented the following as most risky for a small and developing brain:

• Lead (one of the reasons leaded petrol has been banned)

• Methylmercury (think old tooth fillings and found in fish)

• Polychlorinated Biphenyls (PCBs)

• Arsenic (inorganic)

• Toluene (found in hair dyes and certain nail polish amongst other things)

According to the most recent research, since 2006, epidemiological studies have documented six additional developmental neurotoxicants – with pesticides/herbicides featuring particularly prominently:

• Manganese (found in higher concentrations in soy based infant formula, drinking water and from air pollution)

• Fluoride (added to water supply in certain areas)

• Chlorpyrifos (organophosphate pesticide)

• DDT (now banned)

• Trichloroethylene (often found in dry cleaning fluids)

• Polybrominated Diphenyl Ethers (flame retardants)

Phthalates, BPA and air pollution are also of concern:

‘An increased risk of Attention Deficit Disorder has been linked to prenatal exposure to Manganese, organophosphates, and phthalates. Phthalates have also been linked to behaviours that resemble ASD. Prenatal exposure to automotive air pollution (containing Manganese or MMT as a fuel additive) in California has been linked to an increased risk in ASD.’ (1)

Once again, Pesticides are things to watch:

‘Of the newly identified neurodevelopmental toxicants, pesticides constitutes the largest group, as was already the case in 2006.’

We have written extensively on the harm that too much exposure can cause – click here for more and here for some ways (not just buying organic food) that you can reduce your exposure:

‘Three prospective epidemiological birth cohort studies provide new evidence that prenatal exposure to organophosphate pesticide can cause developmental neurotoxicity.’ (1)

How can these potentially toxic materials continue to be used given the risks? Often one of the pushbacks to this research is that surely if these elements are dangerous then they wouldn’t be used? In an ideal world yes and of course we have made progress with banning DDT and Leaded Petrol for example. However, as the research in the Lancet points out, firstly a ‘huge amount of proof is needed for regulation’ and there is also ‘large gaps in the testing of chemicals for developmental neurotoxicity’ which means a lack of data. There is also a systemic belief that ‘new chemicals and technology is safe until proven otherwise’ which is a ‘fundamental problem’. Take asbestos as a prime example. Finally never underestimate the power of corporate lobby. The US/Trump has sided with Dow Chemical who produce Chlorpyrifos (a pesticide) which although has been banned in other parts of the world is still allowed to be sold in the US….

So, taking matters into your own hands where do you find these risks and how can you reduce your exposure??

Pesticides aside, let’s take a look at some of the other risk factors that have been identified and what you can do to avoid:

Methylmercury:

Mercury is widely regarded as a neurotoxin – click here for more. Now, the things we have to watch for are in seafood and if we have old style mercury teeth fillings. Crucially little people seem to be affected more by smaller amounts:

‘Developmental neurotoxicity due to methylmercury occurs at much lower exposures than the concentrations that affect adult brain function’ (1)

Now before you stop eating fish or get your fillings removed a word of caution: firstly fish is an excellent source of DHA/Omega-3 which is crucial for brain development, clicks here for more. So in fact it is about being smart with our consumption. How? Eating in moderation and eating fish lower down the food chain (mercury bioaccumulates meaning it doesn’t break down so if a big fish eats a smaller fish then it will have both it’s mercury and that of the small fish) so think sardines, anchovies, salmon and mackerel and wild is best. Secondly, if you are pregnant do not get your fillings removed as it can release more into the body short term and if you are going to get them removed or replaced make sure you go to a specialist who is properly qualified in this type of procedure.

One other route to consider is algae – or more specifically Chlorella – which has been shown to be pretty effective binding to heavy metals like mercury within the body and helping their safe passage out. Click here for much more on this.

Inorganic Arsenic:

Most people have heard of Arsenic as a deadly poison. The reality is in organic form it is part of the earth’s natural makeup, the trouble comes with the inorganic form and too much can cause damage. It is found within cigarettes and some pesticides, the risk is that it can be found in higher concentrations in drinking water in some parts of the world:

According to the World Health Organisation (WHO): ‘arsenic contamination of groundwater is widespread and there are a number of regions where arsenic contamination of drinking water is significant. It is now recognised that at least 140m people in 50 countries have been drinking water containing arsenic at levels greater than the WHO provisional guideline value of 10 micrograms/litre. (2)

How can you avoid this? Pretty simply, it is about consistently using a good water filter, particularly if you are breastfeeding or making a baby formula. More to follow on which are the best to use and why.

Toluene:

This can be found in certain hair dyes, nail polish, remover solvents and treatments.

How can you avoid this? this is of course one of the reasons that many women do not dye their hair during pregnancy. This is not contained in all dyes and nail varnish of course, however it is worth bearing in mind as the nail does absorb. You can check out the Environmental Working Group’s excellent ‘Skin Deep’ resource for what your particular brand contains as some brands have now stopped using Toluene: https://www.ewg.org/skindeep/. If in doubt just go without, after all, it’s only nine months.

Manganese:

Like arsenic, this is a naturally occurring element and in fact a small amount is needed by the body. However, once again too much can prove to be neurotoxic particularly for a developing brain. Very young children are also disproportionately affected.

This tends to be found in air pollution (a fuel additive MMT is responsible for this), certain fungicides, water and formula can have elevated levels – particularly Soy.

Formula: what you need to know:

We all know breastfeeding is best – particularly for building future immunity but also for brain health, click here for more. However, sometimes it is not possible and formula is necessary (my son had some for example) so, here is what to watch out for when it comes to manganese in infant formula:

According to the Institute of Medicine’s recommendations, infants can consume about 3 micrograms (which is 0.003 milligrams or mg which is what you’ll see on the nutritional values on the back of the pack) during the period of 0-6 months. However, many infant formulas contain more than this, particularly soy formula which has a higher concentration.

Now, before you panic – don’t! A study conducted in infant monkeys suggest that soy based infant formula, which contains a naturally higher concentration of manganese than human or cow’s milk, may produce mild effects on neurological development, although such effects have NOT been documented in humans. Minimising exposure is however a smart strategy however:

So how to avoid: well, obviously minimising exposure to air pollution particularly car exhaust fumes is a good start and then when it comes to formula choosing a formula lower in Manganese and avoiding Soy is a smart strategy. Here are the breakdowns according to brand for 0-6 month formula from highest to lowest:

This is per 100ml feed:

SMA Soy Formula: 0.02 mg = 20 micrograms

Holle: 0.015 mg = 15 micrograms

SMA Infant Formula: 0.012 mg = 12 micrograms

Nanny Care: 0.0084 mg = 8.4 micrograms

Cow&Gate: 0.008 mg = 8 micrograms

Aptamil: 0.008 mg = 8 micrograms

Hipp Organic: 0.0065 mg = 6.5 micrograms

So not only is Hipp Organic Organic (clue in the title!) but it also has the lowest Manganese which is a smarter approach. It is the only one I have used for my son.

BPA and Phthalates:

These are known endocrine disruptors (which means that your hormones can be disrupted causing an imbalance in the body). They are added to many different types of plastic, cosmetic and other consumer products – click here for more – but in a nutshell:

‘Prenatal exposure to phthalates have been linked to behavioural abnormalities characterised by shorter attention span and impaired social interactions. The neurodevelopmental toxicity of these compounds seem to affect mainly boys and could therefore relate to endocrine disruption in the developing brain.’ (1)

How to avoid: given their prevalence in our environment it is all about keeping your exposure as low as possible. For a lot more detail click here but when it comes to phthalates typically they are in added fragrance so simply going for fragrance free products is a great start. When it comes to BPA avoiding plastic is great for the environment of course and here are a few quick tips to assess whether the plastic you are using could contain BPA.

Finally – all of this may seem overwhelming, but actually its all about being aware, being smart about it and reducing your exposures wherever you can. It can seem overwhelming but the principals are pretty simple: avoid pesticides, air pollution and filter your water and air wherever possible. When it comes to cosmetics and things we put into our bodies go with as few artificial ingredients as possible and certainly fragrance free, as well as avoiding plastics. Not rocket science! For the quick summary of how to reduce your risks click here and as always knowledge is power.

References:

1. GRANDJEAN P, LANDRIGAN P: Neurobehavioural effects of developmental toxicity: Lancet Neurology: 2014: 13: 330-38

2. World Health Organisation: www.who.int

3. Institute of Medicine: www.iom.edu.np

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