Increasing folic acid in food could prevent birth defects in the UK

A joint study by Queen Mary University and the School of Advanced Study at the University of London has found that there is no need for an upper limit on folate intake.

The researchers concluded that bread and flour fortified by folic acid, the synthetic form of folate, could help prevent birth defects such as spina bifida and anencephaly. These neural tube defects are prevalent in the UK, affecting one in 500-1,000 pregnancies.

On the basis of a Medical Research Council investigation in 1991, which found that increasing folic acid intake before and during pregnancy prevented most neural tube defects, 81 countries including the US have enacted mandatory minimums for folic acid in cereals.

The UK, however, is yet to introduce mandatory fortification despite several recommendations from the Scientific Advisory Committee on Nutrition. This was due to fears that consumers would exceed the upper limit proposed by the US Institute of Medicine (IOM).

While the IOM found that there was no evidence of folic acid or food folate being related toxicology to detrimental reproductive or developmental health, or cancer, it considered the possible exacerbation of neuropathy in individuals with vitamin B12 deficiency treated with folic acid instead of B12, as harmful.

The new research suggests the IOM’s overall findings are inaccurate, with researchers stating: “The conclusion that ‘higher dose’ folic acid is neurotoxic is based on a flawed analysis of uncontrolled observational studies and hence without evidential value.

“Having such a limit, which has been set at 1mg per day, has acted as a barrier to the wider introduction of mandatory fortification of flour with folic acid to prevent neural tube defects. For both reasons, the upper limit should be discarded.”

The NHS advises pregnant women in the UK to take a daily folic acid supplement but a study based in England found this is often ignored, particularly by younger women and those in ethnic minorities.

The NHS recommends consuming foods rich in natural folic acid including green leafy vegetables, brown rice, granary bread and fortified breakfast cereals, but warns that is ‘almost impossible’ to get enough folic acid from eating these foods only, also recommending the taking of folic acid supplements.

“Failing to fortify flour with folic acid to prevent neural tube defects is like having a polio vaccine and not using it,” said lead author professor Sir Nicholas Wald from the Wolfson Institute of Preventive Medicine at Queen Mary. “With the upper limit removed there is no scientific or medical reason for delaying the introduction of mandatory folic acid fortification in the UK.”

It is reported that an average of two women terminate a pregnancy every day in the UK due to neural tube defects, and  two women giving birth to a baby with a defect each week.

Royal College of Paediatrics and Child Health professor Neena Modi called the research ‘a gamechanger for fortification’, going on to comment that “the government now needs to implement this simple, highly effective public health measure.”