Fortification of grain with folic acid can have a significant effect on reducing the incidence of neural tube defects in children, according to research published this week in the Canadian Medical Association Journal.
The link between the B vitamin and a reduction in the risk of defects such as spina bifida has been known for some time, and many countries have authorised the fortification of flour with folic acid in a bid to ensure a regular intake. Canada approved such a move in 1996, ruling that all grain should be fortified with the vitamin by 1998.
The researchers from Dalhousie University in Halifax, Nova Scotia, looked at the incidence of neural tube defects (NTDs) in the province after November 1998. The team, led by Vidia L. Persad, found that the level of NTDs after fortification was implemented dropped by more than 50 per cent to 1.17 per 1000 births.
They also discovered that simply supplementing the diet with folic acid was not enough to have a significant effect on reducing NTDs.
"Our results help to validate the decision to have food fortified with folic acid and may encourage the implementation of fortification in countries that have not yet implemented such strategies," Persad wrote in the journal. "The recommendations for folic acid supplementation alone did not appear to succeed in reducing the incidence of open NTDs in Nova Scotia, whereas the fortification of grain products with folic acid did result in a significant reduction in the incidence."
A similar study, published in the same journal but focusing on the province of Ontario, showed a 50 per cent reduction in the incidence of NTDs to 8.6 per 10,000 by 1999 as a result of folic acid fortification.
The news will be welcomed by supporters of fortification in many countries, not least the UK, where the Food Standards Agency recently decided not to recommend the fortification of grain on the grounds that not enough was known about the potential adverse effects.
Writing in an editorial accompanying the research, Dr. Rezan Kadir and Dr. Demetrios Economides of the Royal Free Hospital School of Medicine in London said: "It is an effective and inexpensive way to ensure adequate folate levels in all prospective mothers and maximises the effect of folic acid in preventing NTDs."
They also fired a broadside across the bows of the FSA. "The concerns about the safety of food fortification for people at risk of vitamin B 12 deficiency are overexaggerated and not substantiated. The interference with antiepileptic medications is unlikely with the level of fortification required to increase the average daily folic acid intake by 400 µg. Folic acid supplementation of 4 mg is recommended and given to women taking these medications in pregnancy without major concern of their epileptic control.
In addition, there is increasing evidence of potential benefits of folic acid fortification for adults: it prevents folate deficiency anaemia, and it is associated with population-wide reductions in plasma homocysteine concentrations and, at least theoretically, should lead to a reduction in deaths from cardiovascular disease."
Whether these results will be sufficient to convince the authorities in the UK to finally approve folic acid fortification is as yet unknown, but they will certainly be more grist to the mill of the pro-fortification lobby.