- Lucy Bassett
- Oct 29
- 5 min read
They say it’s for our health — but what if this “health policy” is quietly harming many of us?
From April 2024, every bag of flour in the UK — (unless you go out of your way to find unfortified varieties) — now contains synthetic folic acid. A pharmaceutical chemical added to prevent spina bifida in unborn babies. But here’s the uncomfortable truth: the science behind it is shaky, and the risks may outweigh the benefits for much of the population.
Folate vs Folic Acid — What’s the Difference?
Nature’s version of vitamin B9 is folate, found in foods like liver, eggs, leafy greens, and fermented vegetables. It’s easily absorbed and used by the body in its active form, 5-MTHF (methylfolate).
Folic acid, on the other hand, is a synthetic pharmaceutical compound created in a lab. Before your body can use it, it must go through several conversion steps. Many people — especially those with MTHFR or DHFR gene variants — can’t process it properly.
When this happens, unmetabolised folic acid (UMFA) builds up in the blood, which can block natural folate pathways and even interfere with how the brain receives folate. This disruption is now being linked to a range of health issues, including autism spectrum disorders, low B12 absorption, immune dysfunction, and more.
The Research Doesn’t Tell the Whole Story
While folic acid fortification was introduced to reduce neural-tube defects, critics — including pathologist Dr Clare Craig — argue the evidence base used to justify universal fortification is not as robust as it’s presented. Much early trial evidence came from high-risk women (those with prior affected pregnancies), and critics say extrapolating those results to the whole population risks unintended harms for people who cannot process synthetic folic acid efficiently. Some commentators raise concerns about possible adverse outcomes and call for more transparency, targeted approaches, and long-term monitoring. At present, population studies show a fall in NTDs after fortification, but questions remain about long-term and subgroup effects and about whether a one-size-fits-all policy is the best option
The Science Behind the Harm
A 2025 paper by Dr Clare Craig and Dr Timothy Kelly, titled “Disruption of Cerebral Folate Metabolism as a Unifying Framework for Autism Spectrum Disorder Risk and Causation” (Craig & Kelly, 2025), sheds new light on why synthetic folic acid may be doing more harm than good.
Their research explains that when synthetic folic acid floods the system — as it now does through mandatory fortification — it can overwhelm the body’s natural folate metabolism, preventing the active form of folate from reaching the brain where it’s needed most.
They outline several key mechanisms of disruption:
MTHFR or DHFR polymorphisms (genetic mutations) that reduce folate conversion efficiency
Excess folic acid intake from fortified foods and supplements
Autoimmune reactions that block folate transport into the brain
Medications such as methotrexate or valproate that interfere with folate metabolism
The result? An impaired ability to deliver folate to the developing brain — precisely when it’s most critical. This disruption can affect how the brain forms and functions, influencing processes like myelination, synaptic pruning, and neurotransmitter balance.
The authors suggest that both deficiency and overload of folic acid can be harmful — it’s not just about the total amount, but whether the right form of folate reaches the brain in time.
The NHS Itself Warns About Folic Acid
Even the NHS advises that people with the following should avoid folic acid unless specifically advised by a doctor:
Low B12 or pernicious anaemia
A history of cancer
Certain heart conditions such as congestive heart failure
Those on anticonvulsant or cancer medications
People on haemodialysis
Yet, despite these warnings, every loaf of bread, every cake, every biscuit, every bowl of cereal made with standard flour now carries synthetic folic acid — whether you want it or not.
The Ancestral Way — How We Used to Get Folate
Before fortification, humans never needed synthetic folic acid. We obtained folate naturally through nutrient-dense ancestral foods: Liver and organ meats, eggs, leafy greens, raw and fermented dairy, vegetables grown in rich, living soil. These foods contain folate in its bioavailable, active form, along with synergistic nutrients like vitamin B12, choline, and vitamin A — all essential for methylation and healthy development.
When we eat real food, we don’t need lab-made vitamins. Our bodies recognise and utilise natural nutrients perfectly — as nature intended.
What You Can Do
If you’d like to reduce your exposure to synthetic folic acid, here are some practical steps:
Choose unfortified flour – Seek out stoneground or artisan flours from small mills. Many still sell non-fortified options (always check the label).
Bake your own bread – Using unfortified flour or alternative grains such as spelt, rye, or buckwheat. Sourdough fermentation further improves digestibility and nutrient availability.
Avoid fortified cereals and processed foods – Breakfast cereals, shop-bought pastries, and most white breads contain folic acid. Choose simple, traditional whole foods instead.
Get your folate naturally – Eat liver, eggs, leafy greens, and fermented foods regularly. These contain natural folate in active form.
Be cautious with supplements – If you’re taking a multivitamin or prenatal, check the label. Consider supplements containing methylfolate (5-MTHF) or folinic acid instead of folic acid, under professional guidance.
If you have MTHFR or B12 issues, avoid folic acid – It can worsen your symptoms by masking B12 deficiency or blocking natural folate pathways.
Support your gut and soil health – A healthy microbiome can produce folate naturally, and nutrient-rich soil creates nutrient-rich food — the ultimate ancestral loop.
In Summary
Mandatory folic acid fortification might sound like a good idea on paper — but it’s a blunt, one-size-fits-all policy based on weak science.
For those who can’t process synthetic folic acid properly, it may do more harm than good. It’s time to question whether blanket fortification is really in the best interest of the population — or whether we’re being quietly medicated without consent.
When we return to traditional, real food, we don’t need synthetic vitamins. Our bodies — and our babies — thrive best on the wisdom of nature.
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Further Reading & References
Kelly, T. A. & Craig, C. (2025). Disruption of Cerebral Folate Metabolism as a Unifying Framework for Autism Spectrum Disorder Risk and Causation. (Preprint / white paper — not yet peer-reviewed).ResearchGate link
Weston A. Price Foundation. The Case Against Folic Acid Fortification (Wise Traditions).Article page
MRC Vitamin Study Research Group (1991). Prevention of Neural Tube Defects: Results of the Medical Research Council Vitamin Study. The Lancet, 338(8760): 131–137.PubMed abstract
De Wals, P., et al. (2007). Reduction in Neural-Tube Defects after Folic Acid Fortification in Canada. New England Journal of Medicine, 357: 135–142.NEJM DOI pageFull PDF (McGill University)
Crider, K. S., Bailey, L. B., & Berry, R. J. (2011). Folic Acid Food Fortification — Its History, Effect, Concerns, and Future Directions. Nutrients (MDPI). Full article
Lucock, M. (2009). Folic Acid Fortification: A Double-Edged Sword. Public Health Nutrition, 12(12): 2368–2381. PubMed summary
Tam, C., et al. (2012). Circulating Unmetabolized Folic Acid: Relationship to Folate Status and Maternal/Fetal Health. American Journal of Clinical Nutrition.Full text (PMC)
Frye, R. E., et al. (2020). Treatment of Folate Metabolism Abnormalities in Autism. Frontiers in Neuroscience. Review on folinic acid treatment (PMC)
NHS UK. Who Can and Cannot Take Folic Acid. NHS guidance