Folic acid: an update on scientific developments
Over 60 scientific experts from the European Union, Switzerland, the United States and Canada gathered at a scientific meeting held in Uppsala on 21-22 January 2009 to discuss and debate the latest scientific developments regarding folate and folic acid. Jointly organised by the European Food Safety Authority (EFSA) and the Swedish National Food Administration, this event is part of an ongoing EFSA European Scientific Cooperation project on the analysis of the risks and benefits of fortifying food with folic acid. As part of its considerations, the Scientific Cooperation Working Group (ESCO WG) is reviewing the evidence regarding the potential risk of high intakes of folic acid and the need for a review of current guidance on tolerable upper levels of folic acid for all population groups.
During this meeting, participants shared and discussed the most recent scientific information and data available on the possible relationship between dietary intake (from foods including fortified foods and food supplements) of folate and folic acid and cancer risks such as colon, breast and prostate cancer. In an open debate, scientists presented, reviewed and discussed information and latest findings concerning: folate metabolism, epidemiology, animal and mechanistic studies and human studies including both observational studies and intervention trials.
Discussions continued in break-out groups where experts were asked to assess the available evidence with a view to identify a possible association between folic acid intake and cancer risk. Scientists considered issues such as: population groups concerned; intake levels; dose-response relationships; as well as the different sources of dietary folate and folic acid. Scientists also assessed whether data were sufficient to support further qualitative and/or quantitative risk assessment and identified areas of investigation for further research.
Participants reaffirmed the indisputable evidence of benefits of folic acid for reducing the risk of neural tube defects (NTDs) and improving folate status. Scientists agreed that whilst there is a suggestion from animal and mechanistic studies of a relationship between high folic acid intakes and cancer risk, epidemiological data and human studies are inconsistent and not conclusive. Scientists also noted that present data are too sparse to allow a complete risk assessment.
In conclusion, participants reconfirmed the importance of the long standing recommendation for women who might become pregnant to supplement their dietary folate intake with an additional 400 μg of folic acid per day to protect against the risk of NTDs. With respect to the general population, dietary intakes of folic acid (from fortified foods, drinks and supplements) should not exceed the tolerable upper intake level of 1mg/day set by the Scientific Committee on Food.
The outcome of the discussions at the Uppsala meeting are summarized in the meeting report which helped to further inform the work and final report of the ESCO Working Group on the risk and benefits of folic acid. Following discussion by the EFSA Advisory Forum and Scientific Committee in April 2009, the report of the ESCO Working Group was published on the EFSA website in November 2009.