Prenatal Folic Acid and Autism
September 27, 2018 6:38 PM   Subscribe

Can the knowledgeable among you please chime in about Folic Acid/Folate and fetal development, and the connection to Autism? I promise, I am no anti-vaxxer, and just researching this feels wrong somehow. But it seems like studies have found that while Folic Acid supplementation prevents some birth defects, it also corresponds to much higher rates of Autism for at least some populations of women.

I get that no one wants to encourage women to not take prenatal vitamins, and that they have unquestionably helped avoid certain birth defects, but is there any new research about it all? Are there new conclusions about why Black and Latina women are most affected by this phenomenon?

I assume it is a matter of low-income populations/food deserts/and the available cheap industrial food being fortified with even more Folic Acid, and adding that to prenatals just leads to too much of a good thing. But is there any evidence of this or new studies about the possible metabolic aspects for these demographics?

I'm trying hard to find the best current information, and the correct dosage guidelines, but it's hard going. To begin with, most prenatals seem to already have more than the recommended amount of Folic Acid, so that doesn't seem to helpful. Would the dosage guidelines be different for a very petite woman who only weighs about 87lbs? Any info would be appreciated.

Also, I understand that it's not necessarily a bad thing to have Autism, and it's been around forever and it's just the diagnosis that is finally common now, etc. etc. But I'd like to have the most full information I can find on the subject, and I'm finding it really hard to get evidence-based answers. Tldr: it sure looks like Folic Acid supplements cause Autism for at least some segments of the population, and rather than 'shut up and take the pills,' I'd like a little more information/primary sources to allay my concerns, if anyone has any.
posted by anonymous to Health & Fitness (6 answers total) 3 users marked this as a favorite
Respectfully, the specific article you link is one that I found fairly methodologically... poor. There are a lot of logical leaps and uncited statements in it, but putting all of that aside, even that article acknowledges that there are studies that show that folic acid supplementation is associated with reduced, not increased, rates of autism. This is a much more rigorous and clearly articulated review on the subject, which concludes: "our review of the literature suggests that folic acid supplementation in pregnancy may protect against impaired neurodevelopment including ASDs in children, and may improve cognitive function, intellectual, and motor function."

Finally, I don't mean to quibble, but I think an important distinction should be made vis a vis your tl;dr: even the article you linked absolutely does not show that folic acid supplements cause autism. Proving causality scientifically is an extraordinarily rigorous and difficult thing to do; at best they suggest a potential association (but honestly I think they fail at that as well).
posted by telegraph at 6:51 PM on September 27, 2018 [23 favorites]

I think that I would need to see a lot more studies supporting this hypothesis before I could draw any real conclusions about it. In the meantime it's kind of just even more scaremongering on top of all the other things that pregnant women need to think about. I would say that the benefits of taking folic acid outweigh the risks that the study is claiming exist.

The guidelines I have read recommend supplementing 500 mcg (0.5 mg) of folic acid during pregnancy. The study you linked to seems to be concerned about unmetabolised folic acid and states "Consumption of more than 1 mg of folic acid appears to reliably result in unmetabolized FA".

If you are really concerned about this study, I would say that supplementing 500 mcg via a prenatal vitamin would mean that you are at least meeting the recommended folic acid intake but have enough leeway that eating fortified foods wouldn't put you over the 1 mg that they say is a risk. Folic acid fortified foods don't really contain an alarming amount of the vitamin. The serving of breakfast cereal I eat each day contains 150 mcg of folic acid. A couple of slices of bread each day might add another 100 mcg. If I take a prenatal with 500 mcg and eat the bread and cereal, I am consuming ~750 mcg. On top of that I am probably eating quite a lot of folate rich foods, but I would not count that since it's a different form of the vitamin and is processed by the body differently.

"What? No, are you shitting me? Folic acid is good for mothers to be. What are you talking about? It's insane. Stop even thinking about it."

You might disagree with the study and the question, but this answer is really not helpful.
posted by kinddieserzeit at 9:29 PM on September 27, 2018 [10 favorites]

This is a much more rigorous and clearly articulated review on the subject,

Mmmm kinda not really. It's a qualitative review of 22 cohort studies, only 7 of which had even 1000 individuals enrolled and they make the weakest of links from that to their conclusions. And it has 9 authors. There ain't much too that paper other than pub credits and a "more study by us is needed". The paper the OP linked to is a much better paper.

Folic acid supplements aren't as benign as you'd hope considering how hard they are pushed on women at all ages. It is CRITICALLY important to have adequate levels in early pregnancy but that doesn't mean the more the better. For example:
---Folic acid supplements are significantly associated with cancers in several studies. Methotrexate is pretty much just a folate blocker.
---Folic acid supplements can cause neurological injury when given to people with low B12, that's well established. And you can have plenty of serum B12 and not use it well due to some genetic traits so it's not always obvious who will be harmed. This had happened to several of my relatives as we have (and now know about) some weird gene variant that isn't normally harmful.
---methylation pathways are pretty variable between individuals as our inner processes go and are probably epigenetic to some extent. It's interesting stuff actually and we don't know much about it. Most of the consumer science on it is crap but there are some decent papers. Comprehensively, these results suggest that DNA methylation diversity is a source of variability in human groups at macro and microgeographical scales and that population demographic and adaptive histories, as well as the individual ancestry, actually influence DNA methylation profiles.

Having said that: this is one of those topics that's impossible to research on the internet as it's either MTHFR conspiracy theories, people peddling alternative supplements or people accusing you of being a bad mom to a child you haven't conceived yet. I'd say find a good genetic counselor and see if you have any of the known methylation or B12 issues and go from there. If you're an average person you probably have nothing to worry about either way. That's probably the only professional available to you as a layperson for an extended talk. Just make sure it's someone knowledgeable about your specific concern (they can't all know everything).
posted by fshgrl at 11:50 PM on September 27, 2018 [9 favorites]

Catherine DeSoto is an autism quack from way back.
posted by lakeroon at 3:56 AM on September 28, 2018 [1 favorite]

My child has autism and I like to read. There is a lot of research being published about autism. To keep up, I follow Spectrum News which is a joint effort by several legitimate research and advocacy organizations. Here is the latest article (March 2018) about folate, autism, and recently published research. tl;dr: folate may protect against autism or possibly ease symptoms, more research needed.
posted by stowaway at 7:40 AM on September 28, 2018 [1 favorite]

tl;dr: folate may protect against autism or possibly ease symptoms, more research needed.

Its a lot more nuanced than that if you read it and the associated studies. It's a decent article but they casually interchange folic acid and related folonic acid for starters. No point in taking one of you need the other because you have a specific antibody. And they do not talk about the difference between dietary folate and folic acid, dietary folate isn't associated with most of the negative side effects of folic acid. Timing isn't mentioned much either, other than in relation to one study.

OP, see a counselor. You can get tested if autism runs in your family or you're high risk. Then you know where you stand.
posted by fshgrl at 10:07 AM on September 28, 2018 [2 favorites]

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