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The MTHFR gene is all the rage nowadays

MTHFR is popping up on my social media feeds almost every day. There have been frequent reports telling tales that a huge proportion of the population is deficient in MTHFR leading to a range of illnesses such as Schizophrenia, heart disease, and brain damages. This obviously worried me: could I be a carrier of this defect gene? What if my spawn carries it?! Help!!!

…but I don’t like to be worried so I decided to find out more.

MTHFR and scaremongering

The best medicine against these kinds of worries is to have a look at the evidence; to approach the matter with a curious and open mind, but not so open that the brain falls out…

Things we understand and can name properly often stops being threatening as we can start making strategies and take control. It is a bit like in Stephen Kings mini-series “It”; that secretive and nasty clown made me crap my pants, but as soon as they showed the plain, big, fat spider in the end, it was not so scary anymore. OK, I realize that this metaphor was really unsuitable for arachnophobes, but I hope you get my gist…

MTHFR – a golden goose

MTHFR is a gene that is involved in the production of proteins. Its full name sounds even fancier than some European royals: Methylene TetraHydro Folate Reductase; a proper tongue-twister. This name, as you will see soon, makes MTHFR a perfect candidate gene for scaring people and to make money of their fears.  It has turned into a golden goose for snake oil salesmen; a traditional case of weaving a fabric of fear using half-known factoids and half-understood terminology coupled with fancy new techniques and to finally offer a solution for a modest fee.

MTHFR comes in many varieties

The MTHFR gene is as varied as eye color. Just as we look different on the outside, our insides do too. Just because we are different does not mean that we are ill.

It has turned into a golden goose for snake oil salesmen; a traditional case of weaving a fabric of fear using half-known factoids and half-understood terminology coupled with fancy new techniques and to finally offer a solution for a modest fee.

Some people might have a bit lower production of MTHFR and might be completely fine with this just as I am completely fine despite having abnormally high bilirubin due to a strange version of a less well-known enzyme in my liver. I am also fine despite having clubbed thumbs and very small ears. I’m fine. Really. Other people have true deficiencies of MTHFR and are truly ill. However, these individuals are rare, very rare.

I have seen gene tests being offered to find out which variety of MTHFR you and your loved ones have. Of course, for a hefty fee, but who wants to be stingy with money when it comes to our health and well being?

MTHFR Doctor Anna colorful eye

Why MTHFR is so sexy

Most people know what Folate (= folic acid) is (the “F” in MTHFR), often marketed as Vitamin B9. People generally know about folate because it is recommended to take during pregnancy in order to prevent so-called neural tube defects (NTDs) of the baby’s spinal chord and brain. This is scary shit. The fear of hurting one’s owns child can make anyone vulnerable to quacks and charlatans, particularly when they come marching with big words, promises, and simple solutions. I know this very well. Been there myself.

…but stop… just because folate intake during the first 12 weeks of a pregnancy can prevent NTDs in fetuses, it does not mean that the same protective mechanism holds true for children and adults. Cells divide extremely rapidly in a fetus which results in an increased need for folate (1). This is mostly not the case for us non-fetuses.

OK, so we have a combination of a compound people know a bit about combined with a potential danger of damaging children. We are up to a good start.

MTHFR Doctor Anna child

MTHFR – a little learning is a dangerous thing

The next thing that makes MTHFR sexy is its involvement in epigenetics. Epigenetics is the study of heritable changes to gene expression that do not involve the hard code of DNA (GCTA). I hate the word “epigenetics“. I hate it because I loved it so much when I first learned about in grad school and now I see this concept being thrown around like a dirty towel in a locker room. What I hate most is how people are being conned day in and day out by quacks serving half-knowledge and vitamin pills. It makes me sad. It also makes me angry.

Epigenetics is mentioned on many quackery sites claiming that a defective MTHFR gene is the source of all evil that can befall the human body. The reason for this mention is that MTHFR is involved in a reaction that eventually produces a compound called methionine by breaking down a toxic amino acid called homocysteine. Methionine can act as a methyl group donor that is involved in all sorts of processes in the body.

SO WHAT?! Well, in short: homocysteine is toxic, so it is bad to have that swamping your system and methionine is needed to many processes involved in the regulation of genes, in this case: epigenetics.

What is this methylation about?

Methylation of DNA can alter our gene expression, so it is easy to think: more methionine means “more effect on gene expression” (in a positive way).  But does increasing methionine really lead to higher methylation rates?

I would like to show you an example of unexpected effects of increasing certain compounds in the body (2):
“Because of the circular nature of the methionine cycle, however, methionine excess may actually impair DNA methylation by inhibiting remethylation of homocysteine. ” (Waterland, 2006).

Genetics is tricky and seemingly “obvious” things can turn out to be wrong. Excess methionine may not be good.


Doctor Anna 1C metabolism
The complexity of the metabolic pathway of MTHFR. Michiel Adriaens, Frank, Thomas Kelder, et al.

MTHFR – stop worrying so much!

Don’t fall for quacks and their expensive tests, dodgy vitamin pills, and exceedingly boring diets.

If you are very worried and have health issues, go talk to your doctor but be very aware of that a gene test may say very little of what actually is going on in your body.

I bet you, worrying about these things probably gives you more cancer than moderate MTHFR deficiency will ever do.

If one is very concerned about MTHFR, it is much better to do a blood test to see if the compound homocysteine is abnormally high. Homocysteine is what builds up in the bloodstream if MTHFR is not working the way it should. If it is not elevated, then you are fine irrelevant of what type of gene version you have. Well, you might even be fine even with elevated homocysteine because the body can be one resilient bastard.

…and here comes the bomb: The most common reason for homocystinuria (to have too high homocysteine in your body) is not even MTHFR-, but CBS deficiency (cystathionine beta-synthase)! CBS is just less sexy and hasn’t been picked up by the quacks (yet). Stay skeptical!

Doctor Anna amino acids

Vaccines and MTHFR

There has been a lot of talk about people with certain types of MTHFR having a higher risk of contracting vaccine injuries. This makes me want to scream and shout and shake people really hard until they come to their senses! There is simply no evidence showing this. The whole base they build this argument on is, mildly speaking, shaky as you have seen in this article. It is based on misinformation, fear, and greed.

There is no reason not to vaccinate unless you are immunocompromised. As a matter of fact, all of us should vaccinate, not only in order to protect ourselves but also those who are immunocompromised.  To use MTHFR as a reason not to protect yourself, your family and the rest of your fellow human beings is dumb as its best and deadly as its worst. MTHFR is not a problem for the larger part of the population, whereas polio, tetanus, and other deadly diseases very much are if the vaccination rates keep dropping like this. Stop being stupid and go vaccinate.

Doctor Anna polio
This is the reality of polio. Vaccinate!

My humble opinion

Yes, MTHFR is important and those with actual severe deficiencies need medical help. Absolutely, but these individuals are rare, very rare.  I can think of many other things to worry about before freaking out about this. You can read more about this uncommon condition on the NIH website for rare diseases.

I don’t blame people falling for this. It is a jungle out there and who really knows what to believe. One good trick for setting your compass straight is to look towards the experts in the field, those who have learned the trade for decades: the scientists. You would not go to a chef for expert electronics advice nor would you go to an electrician to become a Michelin starred chef. Go to scientists for scientific advice. We are here to help.

Stay curious and Sci Hard!

– Doctor Anna in collaboration with Dr. Alexandra Vasile
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If you are interested in debunking and skepticism? read also my article on the effect of vitamin C on the common cold!

Doctor Anna oranges

MTHFR – additional reading:

(1) Cochrane meta study: Effects and safety of periconceptional oral folate supplementation for preventing birth defects
(2) Waterland, Robert A. “Assessing the effects of high methionine intake on DNA methylation.” The Journal of nutrition 136.6 (2006): 1706S-1710S.
Fragkioudaki, Sofia, et al. “MTHFR gene variants and non-MALT lymphoma development in primary Sjogren’s syndrome.” Scientific Reports 7 (2017).
Dean, Laura. “Methylenetetrahydrofolate reductase deficiency.” (2012).
ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing
A Genetic Test You Don’t Need
Your Guide to Understanding Genetic Conditions


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