expert opinion

The Mandatory Fortification of Staple Foods with Folic Acid

May 16, 2011

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Prof. Dr. med. Wolfgang Herrrmann and Prof. Dr. rer. med. Rima Obeid, Klinische Chemie und Laboratoriumsmedizin (Clinical Chemistry and Laboratory Medicine), Saarland University Hospital, Germany.

“The incidence of neural tube defects (NTDs), in which the spinal column of a child does not close and certain regions of the brain fail to develop, ranges from 0.5 to 14 per 1,000 live births. The most common maternal risk factors for giving birth to a child with a neural tube defect are folate deficiency, obesity and diabetes. Folate deficiency during pregnancy is a risk factor for birth defects other than NTDs. Women of childbearing age should have a satisfactory folate status before conceiving in order to prevent folate-sensitive NTDs. The recommended dietary intake (RDI) for folate has been set at 400 µg. This recommendation does not take into account the special requirements of young women or those of older people. The natural daily intake of folate in the different European countries is on average between 230 and 280 µg. In 1992 the US Center for Disease Control and Prevention called for an additional intake of 400 to 800 µg folic acid per day for all women of childbearing age.

Overall, different international strategies such as educational measures, prevention programs and recommending consumption of food supplements to increase the folate intake of young women have not proved very successful. Hence some countries have decided to fortify staple foodstuffs with folic acid. Mandatory fortification of foods with folic acid for the prevention of NTDs was introduced in the USA in 1998. Since then, more than 50 countries have followed suit. In these countries a marked reduction in the number of NTDs was already observed just one year after the introduction of fortification. The proportion of NTDs that can be prevented by an adequate intake of folic acid is around 20 to 60% of all NTDs. The European registry for birth defects EUROCAT reports a significantly higher prevalence of NTDs in most European countries compared to countries with fortification programs. Thus for example, the incidence of NTDs in Germany is very high in comparison with EUROCAT data: the EUROCAT mean is 7.88 per 10,000 births (between 2004 and 2008), while in Germany it is approximately 12.36 per 10,000 births.

Folate intake can be significantly increased by fortifying foods; usually the amount is around 50 percent of total daily recommended folate intake. Increasing folate intake by fortifying staples such as grain products for the entire population has been the subject of sometimes controversial debate. While folate deficiency is associated with increased risk of developing cancer or other diseases (in addition to NTDs), concerns have been expressed about the possible risk that very high folic acid intake may promote the growth of pre-neoplastic lesions (early stages of tumors). In animal experiments high doses of folic acid have prevented the development of new tumors while promoting the progression of pre-existing tumors. Up to now clinical studies have furnished no uniform evidence of a consistent relationship between complementary folic acid consumption and an increased risk of cancer, which would indicate that it plays no causal role – especially at concentrations below the upper tolerable limit of 1 mg folic acid per day. The usual fortification programs do not exceed or even reach this upper limit. Evidently folic acid plays no proven part in causing cancer, unlike demographic factors (age) or environmental factors (such as smoking or alcohol consumption).

In summary, in countries with a high incidence of neural tube defects, like Germany for instance, the occurrence of such defects could be reduced by 30 to 50 percent through mandatory folic acid fortification. Furthermore, substantial health cost savings could be achieved. The costs of folic acid fortification itself are low (USA: around 1.5 to 3 dollars per ton of wheat flour). Folic acid fortification should be accompanied by regulations to prevent the uncontrolled use of food supplements containing folic acid and limit other, elective fortifications in order to ensure that consumption of folic acid does not exceed the upper tolerable limit in certain parts of the population. Since it is not indicated by consistent results or causal relations, the debated accelerated tumor progression can be ruled out for amounts of fortification prescribed in current programs. The effectiveness and positive cost/benefit ratio of folic acid supplementation for the prevention of NTDs support mandatory folic acid fortification of foodstuffs.”

References

  1. Herrmann W. and Obeid R. The mandatory fortification of staple foods with folic acid: A current controversy in Germany. Dtsch Arztebl Int. 2011; 108(15): 249–254.