The chairman of the UK Food Standard's Agency (FSA) has responded to criticism of the agency's decision not to introduce folic acid fortification in a letter to The Times newspaper.
Last week Professor N. J. Wald of the Department of Environmental and Preventive Medicine at St. Bartholemew's hospital in London and Professor A. V. Hoffbrand of the Royal Free and University College Medical School in London wrote to the paper to urge the agency to reconsider its decision.
They said that the government's advisory committee COMA - of which they are both members - had debated the fortification issue for more than two years, and concluded that the addition of folic acid to flour would reduce the incidence of spina bifida, heart attacks and strokes.
However, Sir John Krebs, chairman of the Food Standards Agency, said in his letter that although the benefits in relation to spina bifida were well documented, the committee was also able to take into account the latest evidence on the possible adverse effects on the elderly.
"Fortification with folic acid could mask vitamin B12 deficiency in up to half a million elderly people. This is three times the level known to COMA when it made its recommendation. The fact that no evidence of adverse effects has yet to be reported in the United States cannot be interpreted as meaning that such effects do not exist, as no data have yet been collected," he wrote.
Krebs continued: "I wholeheartedly agree that public health is essentially a collective strategy. That does mean taking into account the needs of the whole population that could be affected, and balancing the risks and benefits. The agency agreed that the evidence base was insufficient to commend compulsory fortification to health ministers. I am sure that the public would expect nothing less from an agency committed to basing its decisions on sound science whilst acknowledging the uncertainties in present knowledge."
COMA is an advisory scientific committee on nutrition which is in favour of universal folic acid fortification of flour.