Scientists from Queen Mary University of London and the University of London want folic acid added to flour in the UK as they claim it will help protect babies from neural tube defects – anencephaly and spina bifida, which affect one in every 500 - 1,000 pregnancies.
According to the scientists, while women who could become pregnant are advised to take a daily folic acid supplement, many do not do so.
Despite successive recommendations from the Scientific Advisory Committee on Nutrition, and the reduction of neural tube defects in babies in countries that fortify cereals with folic acid, the UK has not introduced mandatory fortification. One reasons given is that this might lead to increased intake of folic acid, a B vitamin, above maximum levels, known as an ‘upper limit’, suggested in 1998 by the US Institute of Medicine (IOM) – now the National Academy of Medicine.
However, a new study by the scientists, published today, suggests the IOM research was ‘flawed’ and there is no need for an upper limit of 1mg/day, just as there is no upper limit for other B vitamins (B1, B2, B5 or B12).
According to the scientists, the IOM analysed the results of studies carried out half a century ago on individuals with B12 deficiency who had been wrongly treated with folic acid and claimed that neurological damage tended to occur more frequently in patients treated with higher doses of folic acid. The IOM concluded that treating individuals with vitamin B12 deficiency with higher doses of folic acid might lead to an increased risk of neurological damage.
But the authors of the new study, who re-analysed the IOM’s data, say they could not find a relationship between the dose of folic acid and the appearance of neurological symptoms. They claim nerve damage was not caused by folic acid, but by not treating B12 deficiency with B12.
The scientists say that now the upper limit is removed, there is no scientific or medical reason for delaying the introduction of mandatory folic acid fortification in the UK and other countries that haven’t adopted this method.
Even with fortification, they still advise pregnant women to take folic acid supplements to achieve a greater level of protection for their unborn child.
Professor Joan Morris, co-author of the new study, said, ‘From 1991, when the protective effect of folic acid was first shown, to 2017, an estimated 3,000 neural tube defects could have been prevented if the UK had adopted the same level of folic acid fortification as in the United States. It’s a completely avoidable tragedy.'
Professor Sir Nicholas Wald, who led a Medical Research Council trial in 1991 that showed increasing folic acid intake immediately before and early in pregnancy prevented most cases of neural tube defects, added, ‘Failing to fortify flour with folic acid to prevent neural tube defects is like having a polio vaccine and not using it.
‘Every day in the UK, on average two women have a termination of pregnancy because of a neural tube defect and every week two women give birth to an affected child.’
Commenting on the new study, Professor Neena Modi, president of the Royal College of Paediatrics and Child Health (RCPCH), said, ‘Folic acid taken in the early stages of pregnancy will prevent around seven of 10 neural tube defects. This new research is a game changer for fortification in allaying concerns about exceeding an upper limit of 1mg/day.
‘In the early stages of pregnancy when neural tube defects arise, many women do not know they are pregnant, others may be unaware of the importance of taking folic acid, or may forget, so fortification of flour, which is harmless if consumed by children and adults, is a logical answer to a problem which can have catastrophic consequences.
‘Around 80 countries already fortify foods and report significant reductions in neural tube defects. It’s a move backed by royal colleges, including the RCPCH, in addition to food manufacturers and other experts. Government now needs to implement this simple, highly effective public health measure.’
A Department of Health and Social Care spokesperson said, ‘We want mums-to-be to have healthy pregnancies, and NHS guidance is that women planning a pregnancy should take a daily supplement of 400 micrograms of folic acid before conception and until the 12th week of pregnancy. We also recommend eating more folate rich foods to reduce the risk of neural tube defects.’
- The study – ‘Public health failure in the prevention of neural tube defects: time to abandon the tolerable upper intake level of folate’, is published in Public Health Reviews.