Joint report of Chief Science Advisor and Royal Society Te Apārangi finds that
the evidence supports mandatory fortification of packaged bread with folic acid
In 2017 the Ministry of Health requested the Prime Minister’s Chief Science Advisor (PMCSA), Sir Peter Gluckman, and the
Royal Society Te Apārangi to formally review the health benefits and potential risks associated with folic acid
fortification of food. The report was provided to the Ministry of Health in June 2018, prior to the end of Sir Peter’s
mandate. It is available at http://www.pmcsa.org.nz/wp-content/uploads/The-health-benefits-and-risks-of-folic-acid-fortification-of-food.pdf
Many countries mandate the fortification of staple foods with folic acid to reduce the rates of neural tube defects.
However, New Zealand relies on industry-led voluntary fortification of bread. This report was requested to provide
government decision makers and the public with a comprehensive and up-to-date understanding of the available scientific
evidence on the health benefits and any potential risks to human health of folic acid fortification of food.
The scientific review was conducted in accord with a general process agreed between the PMCSA and the Society for such
reports. The PMCSA appointed an experienced Research Fellow to undertake the primary research and literature reviews.
The report was overseen by a Royal Society-appointed panel of experts and a respected member of civil society as a lay
observer, and was co-chaired by Sir Peter and Emeritus Professor Robert Beaglehole. There were multiple iterations and
discussions over several months, leading to a draft report that was subjected to Ministry feedback and then
international peer review.
Findings and conclusions
The report concludes that there is compelling evidence that mandatory folic acid fortification is associated with lower
rates of neural tube defects, and that taking folic acid supplements at the recommended doses in pregnancy has no
adverse effects on pregnancy outcome or the child’s health.
No evidence was found to link the use of folic acid supplements or fortification to increased risks of
neurological/cognitive decline, diabetes, or cardiovascular disease; nor was there evidence that unmetabolised folic
acid is harmful.
The Panel reviewed data related to potential effects on cancer risk. Most data suggest no effect on cancer risks at the
doses used in fortification. Some limited evidence from genetic studies of people with different folate metabolism
suggests that higher folate levels may be associated with reduced risks of breast and overall cancer, but at the same
time may also be associated with higher risks of prostate and colorectal cancer. The Panel discussed this issue in great
depth over many months, and took this complex evidence into account in preparing its unanimous advice.
The Panel noted with concern continuing evidence of low levels of folate in women of childbearing age. Based on an
overall assessment of the evidence, and also considering the need to ensure that disadvantaged people including Māori
receive benefit, the Expert Panel unanimously concluded that the benefits of mandatory fortification of packaged bread
with folic acid outweigh any possible adverse effects. Adopting this recommendation will ensure many more women will
have adequate folate status to reduce the risk of neural tube defect, but ensures access to artisan breads for people
who might be concerned about possible, but unproven, adverse effects.
While the absolute number of babies born or pregnancies terminated with neural tube defects are low, the social
emotional and economic costs of such births are high, and folate fortified bread will reduce the number affected.
It is acknowledged that bread intake is not high in all communities and thus other means of fortification or
supplementation should be encouraged. In addition, the Panel strongly encourages the continued use of folic acid
supplements by pregnant women as recommended by their healthcare professionals, and encourages all women of childbearing
age to ensure that their folate intakes are adequate.