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Food additives and their impact on our health

Very small premature baby’s foot held in a hand
Fortifying flour with folic acid may reduce the number of neural tube defect pregnancies – but, say Prof AD Smith and Prof P Saravanan, mandatory fortification also has its dangers. Photograph: Getty Images

With the happy news of the impending royal birth (Harry and Meghan expecting baby in the spring, 16 October) and finally the decision to fortify flour with folate 27 years after the evidence in favour of this (All UK flour to be given folic acid additive, 15 October), surely now is the time for the government to act on its own recent evidence for the need to support the compulsory fortification of salt or bread with iodine.

Iodine deficiency in pregnancy is the commonest treatable cause of low IQ in the world. Recent figures supplied this year by the UK National Diet and Nutrition Survey state that, in 2015-16, although iodine levels in the UK population were satisfactory, they did not meet the criterion for iodine sufficiency in pregnant and lactating women. UK females of reproductive age are unlikely to be iodine-sufficient in pregnancy. This could to lead to a very significant drop in IQ measured in children before the age of nine. The UK is one of only 20 countries in the world that does not have a compulsory iodisation of a food ingredient, for example iodised salt or addition of iodised salt to bread.

The royal trip to the antipodes includes Fiji, where there is iodised salt, and Australia, where there is iodine in the bread. Both these strategies ensure adequate iodine nutrition in pregnancy, unlike the situation in the UK. We urge government action before another 27 years have elapsed.
Prof John Lazarus Cardiff University; chair, UK Iodine Group
Dr Sarah Bath University of Surrey
Dr Emilie Combet University of Glasgow
Prof Kate Jolly University of Birmingham
Janis Hickey British Thyroid Foundation
Mike Marsh Kings College Hospital, London
Prof Margaret Rayman University of Surrey
Dr Malcolm Prentice Croydon NHS Trust
Dr Alex Stewart Public Health England (retd)
Dr Peter Taylor Cardiff University
Dr Mark Vanderpump Past president, British Thyroid Association

• You report that the government has taken a decision to introduce mandatory fortification of flour with folic acid in order to reduce the number of neural tube defect (NTD) pregnancies. But the decision will depend on a report of the committee on toxicology of chemicals in food. We hope that this committee will recognise that folic acid (a synthetic chemical not significantly present in natural food) may have harmful effects.

In countries like the US that have had mandatory fortification since 1998 there is evidence that elderly people exposed to high folic acid levels – in particular those with poor vitamin B12 status – have an increased risk of cognitive impairment. Furthermore, the exposure of pregnant women to additional folic acid should be taken into account: our current evidence is that more than 30% of pregnant women in UK already have supraphysiological blood folate levels. A public health decision of this magnitude should consider the risks as well as the benefits. It has been estimated that fortification may prevent about 96 NTD pregnancies each year in the UK, but in so doing some 670,000 people will be exposed to extra folic acid for each NTD prevented.
Prof AD Smith
University of Oxford
Prof P Saravanan
University of Warwick

• The anticipated change of heart by the government on mandatory folic fortification is to be welcomed. While insight into the nutritional benefits of folic acid in preventing neural tube defects in babies has been in the public domain for many years, it is clearly necessary that this additional proactive step is taken if its impact is to be fully realised.

Cerebral palsy is another disorder that can be prevented by adopting a simple nutritional path, and which may also come to need a similarly proactive approach from government. Research enabled by the Little Foundation offers a better understanding of its causes, pointing to poor levels of docosahexaenoic acid (DHA) in the mother before conception leading to vascular problems for the early-stage foetus that result in the “strokes” that are now seen as the most frequent cause.

Our research indicates that this imbalance could be addressed by increasing the amount of omega-3 in the diet. We hope to mount clinical trials that will show the clear potential for reducing incidence of cerebral palsy by a significant percentage, saving many families heartache and governments many millions in care costs.

As with folic acid, there is already an acceptance of the benefits of an omega-3-rich diet – the World Health Organization and the Food and Agriculture Organization of the United Nations already recommend minimum levels of DHA (200mg / day) during pregnancy – but will this, too, need additional government intervention?
Khalid Hameed
Crossbench peer, House of Lords; chair, The Little Foundation

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