Health: Birth Defects

Lord Turnberg Excerpts

Wednesday 6th November 2013 Lords Chamber

[Lord Turnberg (Lab)]

My Lords, I, too, am grateful to my noble friend Lord Rooker for bringing the subject to our attention and for introducing it in his usual robust and forthright way. It is a privilege, too, of course, to follow the noble Baroness, Lady Grey-Thompson, who spoke so movingly of her personal experiences.

It is pretty obvious that spina bifida in its severe form is indeed a nasty disorder. It affects one or two in every 1,000 pregnancies, causes paralysis of the legs, problems with bladder and bowel control and, in some children, learning difficulties. It can cause serious lifetime problems and distress both for the children and their families. On top of all that, it poses a considerable economic burden on the families and on the health service.

Yet we can prevent—according to my figures—about 70% of cases with a simple dietary manoeuvre; that is, by increasing the intake of folic acid in women before they become pregnant. It was in 1991, 22 years ago, that a study by the Medical Research Council was the first to show that we could prevent these neural tube defects by giving mothers 4 milligrams of folic acid a day, before and during their pregnancy. The incidence went down by about 70% which was a remarkable discovery first made here in the UK. Even much smaller doses were shown to be equally effective. Since then, it has been more or less routine practice to recommend that folic acid should be given to all pregnant women.

However, the problem that soon arose was that simply prescribing it to women who were already pregnant did little or nothing to prevent the disorder. It had to be given before they were pregnant, because the defect arises very early in pregnancy. The neural tube closes at 23 to 27 days after conception; that is before the first period is missed. By the time a woman realises she is pregnant, it is usually too late. She has to take the folic acid before she is pregnant for it to be effective and that immediately eliminates all those women who do not plan their pregnancies. That is particularly the case, for example, in single women and it is exacerbated in those with poor dietary habits whose intake of green vegetables, the natural source of folic acid, is limited. In fact, there is a linear relationship between the level of folic acid in the red cells and plasma and the incidence of neural tube defects. The higher the folate level, the lower the incidence—that is a clear relationship.

So how can we make sure that all women take it before they become pregnant? We inevitably come to the conclusion that we should fortify our food. The Government’s own Expert Advisory Group and COMA, the Committee on Medical Aspects of Nutrition, have been repeatedly recommending that we fortify our flour with folic acid over many years. The idea is that everyone eating average amounts of bread will take about 280 micrograms, about a quarter of a milligram, of folate per day. It is a very small amount but sufficient to prevent spina bifida in a majority of cases. We in the UK have unfortunately not taken that advice, even though more than 70 other countries around the world, including the USA and Canada, supplement their flour with folic acid.

Of course, there is always a reluctance to add things to the diet that everyone is going to eat. Noble Lords have talked about this. Worries about side-effects and unexpected adverse events are always raised and it is usually wise to be cautious. In the case of folic acid there were worries about the possibility of two sorts of danger: that it could cause cancer; and that it might cause a peripheral neuropathy in those elderly people who were also deficient in vitamin B12. This is a disorder of the nerves going to the arms and legs, a condition caused by a combination of B12 deficiency and folic acid excess. So delay in taking up the recommendations of COMA was inevitable until these dangers could be eliminated.

Now we know from a huge number of studies that they have indeed been eliminated. In the meta-analysis that noble Lords have referred to of a large number of trials by Vollset and his colleagues in the last year, trials covered almost 50,000 individuals given a largish dose of 5 milligrams a day for five years or more and there was no sign of an increase in the overall number of all cancers or of any individual specific type of cancer. Incidentally, these trials were done largely in the belief that folic acid might prevent coronary artery disease. It did not show that, but it did show that cancers did not increase, which was a useful side-effect. Nor has there been any sign that the B12 deficient neuropathy I mentioned has increased in the population of America or Canada where they have been fortifying their flour since 1998, 15 years ago. Incidentally, the manufacturers of breakfast cereals—All-Bran and the like—routinely fortify them with a range of vitamins, including folic acid. Perhaps the noble Baroness, Lady Grey-Thompson, could take breakfast cereals; that might help her.

It is hard now to refute the scientific evidence, gathered from huge populations, that supplementing the diet of everyone by an average of 280 micrograms a day of this vitamin is harmless to the population at large. It clearly reduces the incidence of this nasty and burdensome disease in our children. It is more than 20 years since we discovered that we could prevent neural tube defects by this simple measure. The discovery was made here in the UK and it is high time we caught up with much of the rest of the world and took advantage of what we now know.