Experts have warned the baking industry against adding folic acid to flour or bread, linking an excess of the vitamin with increased risk of cancer.
A new paper published in the British Journal of Nutrition found that fortified folic acid is broken down by the liver, however when eaten in its natural form, for example in green vegetables, it is broken down in the stomach.
The authors of the study claimed that if the liver received too much folic acid then it would be released into the blood undigested. An excess in the blood stream has been linked to bowel and breast cancer.
In June this year the Food Standards Agency (FSA) had agreed that a form of mandatory fortification of flour or bread with folic acid should be recommended to UK health ministers as part of a package of measures to help prevent neural tube defects (NTDs) in new born babies.
Fortification could prevent between 77 and 162 NTD pregnancies a year.
However, uncertainty regarding cancer risk had already led the Agency to order further research from the Scientific Advisory Group on Nutrition (SACN), which guided its decision to recommend fortification (see British Baker, October 26, pg 4).
An expert group of members of SACN and cancer experts, is now examining two studies on colorectal cancer risk which were not published at the time of SACN’s original report.
Previously, the SACN concluded that evidence for a relationship between folic acid and cancer risk was unclear.