Adding the nutrient to flour has been the subject of debate in Britain as a possible way to lower the number of births affected by neural tube defects (NTDs), which affects some 900 pregnancies a year. England's Chief Medical Officer Sir Liam Donaldson in October asked the Food Standards Agency's (FSA) Scientific Advisory Group on Nutrition (SACN) to consider in more detail at two studies by Cole and Mason. The FSA had recommended to go ahead with a program of mandatory fortifiction of bread or flour with folic acid to reduce incidence of NTDs, but a postponement was called over fears that the studies shone light on a connection between folic acid and colorectal cancer. However, Dr Roger Bayston, Association for Spina Bifida and Hydrocephalus and colleagues have assessed the papers and concluded that they provide "no grounds for concern" to go ahead with fortification. The group is now calling on the government to proceed with folic acid fortification. Science The Cole paper was based on results of a randomised trial of folic acid in prevention of growths on the colon on a group of patients who had them removed. But Dr Bayston said the the conclusions have been misinterpreted. He said: "The paper does not show that folic acid supplementation poses a hazard. "It relates to colorectal adenomas (benign tumours), not carcinomas. The incidence of adenomas in those who were and were not allocated folic acid supplements was almost identical." The paper by Mason looks at a temporal association between folic acid fortification and an increase in colorectal cancer in the USA and Canada. Mandatory fortification was in place in the US by the beginning of 1998 and in Canada the following year. Dr Bayston said the study suggests that there is a possibility of a casual link, but the data does "not support this." He adds that the rise in colorectal cancer incidence started before the introduction of fortification on any large scale and "could not have been caused by fortification." They concluded that the FSA and Chief Medical Officer can be "confident in recommending that the UK government introduce the mandatory fortification of flour, which could prevent about 400 pregnancies affected by neural tube defects each year, reducing both the number of terminations of pregnancy and of children born with these defects." Raging The debate over whether folic acid fortification should go ahead has raged for more than five years. 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.