Ministers request folic acid-colorectal cancer review
another look at studies on folic acid fortification and colorectal
cancer risk before making a decision on mandatory fortification of
some food products.
The addition of folic acid to bread or flour has been under consideration in the UK for a number of years as a way to reduce the incidence of pregnancies affected by neural tube defects (NTDs) by between 11 and 18 per cent. Between 700 and 900 pregnancies in the UK are affected by NTDs each year, not including miscarriages. In June the FSA made the decision to recommend mandatory fortification to health ministers, although no decision has been made as to whether this would be at the flour milling or bread-making stage. Now, however, Chief Medical Officer of England Sir Liam Donaldson has asked the FSA's board to have its Scientific Advisory Group on Nutrition (SACN) consider in further detail two recently published studies on folic acid and colorectal cancer risk. In one of the studies (see full reference below), scientists from Dartmouth Medical School in the US said that the view of folate supplementation help to prevent colorectal tumours is misleading, and that supplementation may even aggravate the risk of such tumours. "Our study indicates that folate, when administered as folic acid for up to six years, does not decrease the risk of adenoma formation in the large intestine among individuals with previously removed adenomas," said Bernard Cole and his colleagues. They admitted that "the evidence for an increased risk of adenomas is equivocal and requires further research", but urged "in view of the fortification of the US food supply with folate...this line of investigation should have a high priority". The second study (see reference below) looks at trends in colorectal cancer incidence in the USA and Canada, where fortification was made mandatory in 1998. SACN did actually considered a broad range of evidence for the relationship between folic acid and cancer prior to including results from these two studies "SACN concluded at this stage that the evidence for a relationship between folic acid and increased or reduced cancer risk was unclear," said the agency. A spokesperson for the FSA told FoodNavigator.com that SACN's further consideration of the research does not mean that the FSA is redrawing its advice. She was not able to give an indication of how long the review of the studies will take, nor when the heath ministers are likely to make a decision on fortification. The latter decision lies with the Department of Health. This is not the first time that a possible negative impact of folic acid fortification has been brought into the debate. Indeed, it first looked like the FSA would issue its positive advice on fortification in summer 2006. The SACN then said, however, that it needed more time to look at additional evidence on the risks and benefits of fortification, particularly in relation to increasing folate intake over 1mg per day. The FSA last considered mandatory fortification in 2002, but the SACN decided not to adopt it at that time because of concerns that folate consumption in excess of 1000 micrograms (1mg) per day could delay the detection of vitamin B12 deficiency (which can have severe neurological consequences) in older people. Since then, some research has indicated that B12 deficiency would be masked only with folate consumption of more than 5000 micrograms per day. When the SACN's advice was finally forthcoming, it came with the condition that there be controls on voluntary fortification, and clear guidance be given on the appropriate use of supplements containing folic acid. It is estimated that around 13.3 million people in the UK currently consume too little folate, natural dietary sources of which include grains, lentils, chick peas and green leafy vegetables. No other European country has yet introduced the measure, but Ireland is at an advanced stage in the process. References: Journal of the American Medical Association 2007; 297:2351-2359 Title: "Folic acid for the prevention of colorectal adenomas"Authors: Cole BF, Baron JA, Sandler RS, et al. Journal: Cancer Epidemiol Biomarkers Prev 2007; 16(7):1325-9 Title: "A temporal association between folic acid fortification and an increase in colorectal cancer rates may be illuminating important biological principles: a hypothesis"