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MTHFR and why not to take folic acid during pregnancy

What follows is the extract of an interview we carried out with another nutritionist on MTHFR.


I do know a little about MTHFR as I read Dr Ben Lynch’s site MTHRF.Net. It’s fascinating stuff!

What exactly is MTHFR and how does this affect you if you are trying to get pregnant?

Thank you Oliver! It’s a complicated subject but I’ll do my best to explain it here.

The MTHFR gene helps people metabolise Folate, which is a water soluble B vitamin also called Vitamin B9.

A quick science bit: in the human body there are around 34 MTHFR genes that we currently know of and all the research focuses on just two of them – the one at the position C677T on the gene and one at A1298C position – and mostly it’s the C677T that’s winning the popularity contest in research fields. (I say this as I have MTHFR A1298C).

There are situations — namely during pregnancy — when women with a particular variation in the MTHFR gene C677T and A1298C should eat more Folate to prevent birth defects and/ or early miscarriage. Many GPs and Midwives advise pregnant women to take Folic Acid supplements because this nutrient is seen to be vital for early foetal development. This has been the message up until now and in women without MTHFR issues, this seems to improve the prevention of Neural Tube Defects (NTDs) and Spina Bifida. However, this isn’t the best advice for those with mutations in the MTHFR gene.

Foods high in Folate, such as leafy greens, are in an ‘active’ form, meaning they are absorbed straight into the body. However, if you have two mutated or changed copies of the MTHFR gene, you’ll be more at risk of chronic disease and may have difficulties in conceiving and sustaining a pregnancy as the gene is only working to allow 50 or 30% of the folate to be converted to help DNA replication.

Folic acid is a man-made synthetic and ‘inactive’ therefore needs to be broken down many times before it is in the active L-Methlyfolate version available to your body.

So, if you take Folic Acid supplements and you have a mutation in the MTHFR gene, natural Folate will be stopped from being absorbed by cells in your body because the Folic Acid is basically getting in the way as it needs to be converted before it can get into the cell. Folate is really important for DNA replication, which is why it is recommended in the early stages of pregnancy, if cells are not getting Folate this can mean that the foetus doesn’t get enough Folate for embryo development and future growth. Therefore, taking folic acid can be extremely detrimental to you if you have mutations in MTHFR genes. Some folic acid will get into the cell as if it is converted then you have access to it. However those with mutations in some cases are down up to 50-70% in this conversion process, so already starting off in deficit!

Many might say, ‘Well I won’t have a prenatal with Folic Acid in – job done!’ Unfortunately, Folic Acid is in almost every brand of pre-natal and wellbeing supplement in supermarkets and chemists as many companies haven’t caught up with this issue yet. Also, if you eat a diet that has bread, pasta and other processed food, invariably Folic Acid has already been added.

In regards to Folic Acid, I understand that if you have a mutation in the genes this won’t be great for you. I also see Folic Acid added in loads of packets of food, alternatives to non-dairy milk and other weird things I wouldn’t have thought!

You’re right Oliver , it sneaks into everything! So you have to be a ‘health detective’. Places like the USA, Canada, and Australia and some South American countries added Folic Acid as a mandatory step into baked goods in the late 1990s as the spinal column starts to form in week 5 and the neural tube closes in the space of 1 week! So their argument was it is useful for those in early stages. The reason the UK hasn’t made it a mandatory step is because in the 1990s some of our scientists had reservations about Folic Aid causing colon cancer so put a strong case against it as they were worried about the conversion of this synthetic substance into the active form needed by the body. In the meantime if your doctor or midwife suggests Folic Acid, do some research, the folate I’m talking about is a superior form as it is active! Also there are loads of studies on academic journals like pub med attesting to folic acid being detrimental to people with MTHFR and with polls looking at as many as 1 in 6 of us having this gene, its one to look into for chromosomal issues.

Association between the MTHFR C677T polymorphism and recurrent pregnancy loss: a meta-analysis.

Association between MTHFR 1298A>C polymorphism and spontaneous abortion with fetal chromosomal aneuploidy.

Ok, loads of new info for most people I would say…. What are the next steps if you have been having multiple miscarriages or have been trying for more than two years without getting pregnant?

If you are concerned I would do some research and get a blood test for MTHFR (from your GP or a Haematologist) to see if you have the mutation.

How can we work around these mutations Angela?

As mentioned earlier, this whole area is new and is called Epigenetics medicine. Epigenetics looks at how our external forces such as environment, stress levels and lifestyle can influence our genes. Years ago it was thought that we inherited everything from our family line. However, through looking at epigenetics we now know this isn’t always the case. We may have the same genes as our family with the same risk of certain conditions, but we can influence how these genes are affected by how we live our lives; by the food we eat, the toxins we’re exposed to, the exercise we choose, our habits and stress levels.

Nutrigenomics is the study of how foods affect our genes and how individual genetic differences can affect the way we respond to nutrients in the foods we eat as genes may remain triggered or silent even if mutated and are only activated if lifestyle choices and other things turn them on. A good example of this is a large number of the Italian population have 2 copies of the MTHFR gene and their incidence of chronic diseases is less than the US and the UK. What we do know is that the Mediterranean diet is widely tipped as the healthiest in the world.

The high prevalence of thermolabile 5-10 methylenetetrahydrofolate reductase (MTHFR) in Italians is not associated to an increased risk for coronary artery disease (CAD).

To conclude on epigenetic management what would you say is key?

1) Start eating more uncooked leafy greens and beans, but not baked beans!

2) Look into the ‘Clean 15 and dirty dozen’ in regards to foods that are heavily contaminated with pesticides and eat less chemicals

3) Look at things you can change – food, lifestyle and pollution.

4) Stress will cause you to burn out, so meditate, do yoga, do things you love and take a break!

5) Look at your family and do a check on their health, particularly if there are oestrogen based cancers, cysts, fibroids, PCOS and endometriosis. See a nutritionist to get you off to a good start – it will save you time and stress as this is something that needs to be under control before starting the baby game, as pregnancy increases oestrogen massively!

6) Read all you can on this subject and how it relates to fertility.

7) Get some basic blood and genetic tests done.

8) Throw away any food and supplements that have inactive B vitamins such as Folic Acid or cyanocobalamin b12 (read the labels) and take a proactive stance on your health!

Thanks to Angela Heap of Fertile Ground nutrition

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